Academic literature on the topic 'Primary neuron'

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Journal articles on the topic "Primary neuron"

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Sun, Wensheng, Ellisha N. Marongelli, Paul V. Watkins, and Dennis L. Barbour. "Decoding sound level in the marmoset primary auditory cortex." Journal of Neurophysiology 118, no. 4 (October 1, 2017): 2024–33. http://dx.doi.org/10.1152/jn.00670.2016.

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Neurons that respond favorably to a particular sound level have been observed throughout the central auditory system, becoming steadily more common at higher processing areas. One theory about the role of these level-tuned or nonmonotonic neurons is the level-invariant encoding of sounds. To investigate this theory, we simulated various subpopulations of neurons by drawing from real primary auditory cortex (A1) neuron responses and surveyed their performance in forming different sound level representations. Pure nonmonotonic subpopulations did not provide the best level-invariant decoding; instead, mixtures of monotonic and nonmonotonic neurons provided the most accurate decoding. For level-fidelity decoding, the inclusion of nonmonotonic neurons slightly improved or did not change decoding accuracy until they constituted a high proportion. These results indicate that nonmonotonic neurons fill an encoding role complementary to, rather than alternate to, monotonic neurons. NEW & NOTEWORTHY Neurons with nonmonotonic rate-level functions are unique to the central auditory system. These level-tuned neurons have been proposed to account for invariant sound perception across sound levels. Through systematic simulations based on real neuron responses, this study shows that neuron populations perform sound encoding optimally when containing both monotonic and nonmonotonic neurons. The results indicate that instead of working independently, nonmonotonic neurons complement the function of monotonic neurons in different sound-encoding contexts.
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Shin, Seung Min, Yongsong Cai, Brandon Itson-Zoske, Chensheng Qiu, Xu Hao, Hongfei Xiang, Quinn H. Hogan, and Hongwei Yu. "Enhanced T-type calcium channel 3.2 activity in sensory neurons contributes to neuropathic-like pain of monosodium iodoacetate-induced knee osteoarthritis." Molecular Pain 16 (January 2020): 174480692096380. http://dx.doi.org/10.1177/1744806920963807.

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The monosodium iodoacetate knee osteoarthritis model has been widely used for the evaluation of osteoarthritis pain, but the pathogenesis of associated chronic pain is not fully understood. The T-type calcium channel 3.2 (CaV3.2) is abundantly expressed in the primary sensory neurons, in which it regulates neuronal excitability at both the somata and peripheral terminals and facilitates spontaneous neurotransmitter release at the spinal terminals. In this study, we investigated the involvement of primary sensory neuron-CaV3.2 activation in monosodium iodoacetate osteoarthritis pain. Knee joint osteoarthritis pain was induced by intra-articular injection of monosodium iodoacetate (2 mg) in rats, and sensory behavior was evaluated for 35 days. At that time, knee joint structural histology, primary sensory neuron injury, and inflammatory gliosis in lumbar dorsal root ganglia, and spinal dorsal horn were examined. Primary sensory neuron-T-type calcium channel current by patch-clamp recording and CaV3.2 expression by immunohistochemistry and immunoblots were determined. In a subset of animals, pain relief by CaV3.2 inhibition after delivery of CaV3.2 inhibitor TTA-P2 into sciatic nerve was investigated. Knee injection of monosodium iodoacetate resulted in osteoarthritis histopathology, weight-bearing asymmetry, sensory hypersensitivity of the ipsilateral hindpaw, and inflammatory gliosis in the ipsilateral dorsal root ganglia, sciatic nerve, and spinal dorsal horn. Neuronal injury marker ATF-3 was extensively upregulated in primary sensory neurons, suggesting that neuronal damage was beyond merely knee-innervating primary sensory neurons. T-type current in dissociated primary sensory neurons from lumbar dorsal root ganglia of monosodium iodoacetate rats was significantly increased, and CaV3.2 protein levels in the dorsal root ganglia and spinal dorsal horn ipsilateral to monosodium iodoacetate by immunoblots were significantly increased, compared to controls. Perineural application of TTA-P2 into the ipsilateral sciatic nerve alleviated mechanical hypersensitivity and weight-bearing asymmetry in monosodium iodoacetate osteoarthritis rats. Overall, our findings demonstrate an elevated CaV3.2 expression and enhanced function of primary sensory neuron-T channels in the monosodium iodoacetate osteoarthritis pain. Further study is needed to delineate the importance of dysfunctional primary sensory neuron-CaV3.2 in osteoarthritis pain.
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Reyes, Laura D., Tessa Harland, Roger L. Reep, Chet C. Sherwood, and Bob Jacobs. "Golgi Analysis of Neuron Morphology in the Presumptive Somatosensory Cortex and Visual Cortex of the Florida Manatee (Trichechus manatus latirostris)." Brain, Behavior and Evolution 87, no. 2 (2016): 105–16. http://dx.doi.org/10.1159/000445495.

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The current study investigates neuron morphology in presumptive primary somatosensory (S1) and primary visual (V1) cortices of the Florida manatee (Trichechus manatus latirostris) as revealed by Golgi impregnation. Sirenians, including manatees, have an aquatic lifestyle, a large body size, and a relatively large lissencephalic brain. The present study examines neuron morphology in 3 cortical areas: in S1, dorsolateral cortex area 1 (DL1) and cluster cortex area 2 (CL2) and in V1, dorsolateral cortex area 4 (DL4). Neurons exhibited a variety of morphological types, with pyramidal neurons being the most common. The large variety of neuron types present in the manatee cortex was comparable to that seen in other eutherian mammals, except for rodents and primates, where pyramid-shaped neurons predominate. A comparison between pyramidal neurons in S1 and V1 indicated relatively greater dendritic branching in S1. Across all 3 areas, the dendritic arborization pattern of pyramidal neurons was also similar to that observed previously in the afrotherian rock hyrax, cetartiodactyls, opossums, and echidnas but did not resemble the widely bifurcated dendrites seen in the large-brained African elephant. Despite adaptations for an aquatic environment, manatees did not share specific neuron types such as tritufted and star-like neurons that have been found in cetaceans. Manatees exhibit an evolutionarily primitive pattern of cortical neuron morphology shared with most other mammals and do not appear to have neuronal specializations for an aquatic niche.
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Turner, Emily C., Nicole A. Young, Jamie L. Reed, Christine E. Collins, David K. Flaherty, Mariana Gabi, and Jon H. Kaas. "Distributions of Cells and Neurons across the Cortical Sheet in Old World Macaques." Brain, Behavior and Evolution 88, no. 1 (2016): 1–13. http://dx.doi.org/10.1159/000446762.

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According to previous research, cell and neuron densities vary across neocortex in a similar manner across primate taxa. Here, we provide a more extensive examination of this effect in macaque monkeys. We separated neocortex from the underlying white matter in 4 macaque monkey hemispheres (1 Macaca nemestrina, 2 Macaca radiata, and 1 Macaca mulatta), manually flattened the neocortex, and divided it into smaller tissue pieces for analysis. The number of cells and neurons were determined for each piece across the cortical sheet using flow cytometry. Primary visual cortex had the most densely packed neurons and primary motor cortex had the least densely packed neurons. With respect to differences in brain size between cases, there was little variability in the total cell and neuron numbers within specific areas, and overall trends were similar to what has been previously described in Old World baboons and other primates. The average hemispheric total cell number per hemisphere ranged from 2.9 to 3.7 billion, while the average total neuron number ranged from 1.3 to 1.7 billion neurons. The visual cortex neuron densities were predictably higher, ranging from 18.2 to 34.7 million neurons/cm2 in macaques, in comparison to a range of 9.3-17.7 million neurons/cm2 across cortex as a whole. The results support other evidence that neuron surface densities vary across the cortical sheet in a predictable pattern within and across primate taxa.
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Sutter, M. L., and C. E. Schreiner. "Physiology and topography of neurons with multipeaked tuning curves in cat primary auditory cortex." Journal of Neurophysiology 65, no. 5 (May 1, 1991): 1207–26. http://dx.doi.org/10.1152/jn.1991.65.5.1207.

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1. The physiology and topography of single neuron responses along the isofrequency domain of the middle- and high-frequency portions [characteristic frequencies (CFs) greater than 4 kHz] of the primary auditory cortex (AI) were investigated in the barbiturate-anesthetized cat. Single neurons were recorded at several locations along the extent of isofrequency contours, defined from initial multiple-unit mapping. For each neuron a high-resolution excitatory tuning curve was determined, and for some neurons high-resolution two-tone tuning curves were recorded to measure inhibitory/suppressive areas. 2. A physiologically distinct population of neurons was found in the dorsal part of cat AI. These neurons exhibited two or three distinct excitatory frequency ranges, whereas most neurons in AI responded with excitation to a single narrow frequency range. These were called multipeaked neurons because of the shape of their tuning curves. At frequencies between the excitatory regions, the multipeaked neurons were inhibited or unresponsive. 3. Multipeaked neurons exhibited several distinct threshold minima in their frequency tuning curves. Most of the multipeaked neurons (88%) displayed two frequency minima, whereas the rest exhibited three minima. 4. The frequency separation between threshold minima was less than 1 octave in 71% of the double-peaked neurons recorded. Occasionally, the frequency peaks of these neurons closely corresponded to a response to second and third harmonics without a response to the fundamental frequency. 5. Multipeaked neurons exhibited a wide range of total bandwidths (highest excitatory frequency minus lowest excitatory frequency expressed in octaves). Bandwidths of the isolated peaks within the same neuron were also quite variable. 6. Response latencies to tones with frequencies within each peak of a multipeaked neuron could vary considerably. In 71% (17) of the neurons, tones corresponding to the high-frequency peak (CFh) elicited a longer response latency (greater than 4 ms) than those corresponding to the low-frequency peak (CF1). 7. Inhibitory/suppressive bands, as demonstrated with a two-tone paradigm, were often present between the peaks. Typically, neurons with excitatory peaks of similar response latencies showed an inhibitory band located between the peaks. 8. Ninety percent of the topographically localized multipeaked neurons were in the dorsal part of AI (greater than 1 mm dorsal to the maximum in the sharpness-of-tuning map). Although these neurons were restricted to dorsal AI, only 35% of neurons in this region were multipeaked. 9. Multipeaked neurons could show decreased response latencies and thresholds to two-tone combinations.(ABSTRACT TRUNCATED AT 400 WORDS)
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Cao, Jinyan, and John Meitzen. "Perinatal activation of ERα and ERβ but not GPER-1 masculinizes female rat caudate-putamen medium spiny neuron electrophysiological properties." Journal of Neurophysiology 125, no. 6 (June 1, 2021): 2322–38. http://dx.doi.org/10.1152/jn.00063.2021.

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This study is the first to demonstrate that estradiol and estrogen receptor α and β stimulation during early development sexually differentiates the electrophysiological properties of caudate-putamen medium spiny neurons, the primary output neuron of the striatal regions. Overall, this evidence provides new insight into the neuroendocrine mechanism by which caudate-putamen neuron electrophysiology is sexually differentiated and demonstrates the powerful action of early hormone exposure upon individual neuron electrophysiology.
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Han, Jingfeng, Weiping Tao, Wei Cui, and Jiawei Chen. "Propofol via Antioxidant Property Attenuated Hypoxia-Mediated Mitochondrial Dynamic Imbalance and Malfunction in Primary Rat Hippocampal Neurons." Oxidative Medicine and Cellular Longevity 2022 (January 18, 2022): 1–16. http://dx.doi.org/10.1155/2022/6298786.

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Background. Hypoxia may induce mitochondrial abnormality, which is associated with a variety of clinical phenotypes in the central nervous system. Propofol is an anesthetic agent with neuroprotective property. We examined whether and how propofol protected hypoxia-induced mitochondrial abnormality in neurons. Methods. Primary rat hippocampal neurons were exposed to propofol followed by hypoxia treatment. Neuron viability, mitochondrial morphology, mitochondrial permeability transition pore (mPTP) opening, mitochondrial membrane potential (MMP), and adenosine triphosphate (ATP) production were measured. Mechanisms including reactive oxygen species (ROS), extracellular regulated protein kinase (ERK), protein kinase A (PKA), HIF-1α, Drp1, Fis1, Mfn1, Mfn2, and Opa1 were investigated. Results. Hypoxia increased intracellular ROS production and induced mPTP opening, while reducing ATP production, MMP values, and neuron viability. Hypoxia impaired mitochondrial dynamic balance by increasing mitochondrial fragmentation. Further, hypoxia induced the translocation of HIF-1α and increased the expression of Drp1, while having no effect on Fis1 expression. In addition, hypoxia induced the phosphorylation of ERK and Drp1ser616, while reducing the phosphorylation of PKA and Drp1ser637. Importantly, we demonstrated all these effects were attenuated by pretreatment of neurons with 50 μM propofol, antioxidant α-tocopherol, and ROS scavenger ebselen. Besides, hypoxia, propofol, α-tocopherol, or ebselen had no effect on the expression of Mfn1, Mfn2, and Opa1. Conclusions. In rat hippocampal neurons, hypoxia induced oxidative stress, caused mitochondrial dynamic imbalance and malfunction, and reduced neuron viability. Propofol protected mitochondrial abnormality and neuron viability via antioxidant property, and the molecular mechanisms involved HIF-1α-mediated Drp1 expression and ERK/PKA-mediated Drp1 phosphorylation.
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Carandini, Matteo, Horace B. Barlow, Lawrence P. O'keefe, Allen B. Poirson, and J. Anthony Movshon. "Adaptation to contingencies in macaque primary visual cortex." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 352, no. 1358 (August 29, 1997): 1149–54. http://dx.doi.org/10.1098/rstb.1997.0098.

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We tested the hypothesis that neurons in the primary visual cortex adapt selectively to contingencies in the attributes of visual stimuli. We recorded from single neurons in macaque V1 and measured the effects of adaptation either to the sum of two gratings (compound stimulus) or to the individual gratings. According to our hypothesis, there would be a component of adaptation that is specific to the compound stimulus. In a first series of experiments, the two gratings differed in orientation. One grating had optimal orientation and the other was orthogonal to it, and therefore did not activate the neuron under study. These experiments provided evidence in favour of our hypothesis. In most cells adaptation to the compound stimulus reduced responses to the compound stimulus more than it reduced responses to the optimal grating, and adaptation to the optimal grating reduced responses to the optimal grating more than it reduced responses to the compound stimulus. This suggests that a component of adaptation was specific to (and caused by) the simultaneous presence of the two orientations in the compound stimulus. To test whether V1 neurons could adapt to other contingencies in the stimulus attributes, we performed a second series of experiments, in which the component gratings were parallel but differed in spatial frequency, and were both effective in activating the neuron under study. These experiments failed to reveal convincing contingent effects of adaptation, suggesting that neurons cannot adapt equally well to all types of contingency.
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Hardwick, Laura J. A., and Anna Philpott. "xNgn2 induces expression of predominantly sensory neuron markers in Xenopus whole embryo ectoderm but induces mixed subtype expression in isolated ectoderm explants." Wellcome Open Research 3 (November 8, 2018): 144. http://dx.doi.org/10.12688/wellcomeopenres.14911.1.

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Proneural basic-helix-loop-helix (bHLH) proteins, such as Neurogenin2 (Ngn2) and Ascl1, are critical regulators at the onset of neuronal differentiation. Endogenously they have largely complementary expression patterns, and have conserved roles in the specification of distinct neuronal subtypes. In Xenopus embryos, xNgn2 is the master regulator of primary neurogenesis forming sensory, inter- and motor neurons within the neural plate, while xAscl1 is the master regulator of autonomic neurogenesis, forming noradrenergic neurons in the antero-ventral region of the embryo. Here we characterise neuronal subtype identity of neurons induced by xNgn2 in the ectoderm of whole Xenopus embryos in comparison with xAscl1, and in ectodermal “animal cap” explants. We find that the transcriptional cascades mediating primary and autonomic neuron formation are distinct, and while xNgn2 and xAscl1 can upregulate genes associated with a non-endogenous cascade, this expression is spatially restricted within the embryo. xNgn2 is more potent than xAscl1 at inducing primary neurogenesis as assayed by neural-β-tubulin. In ectoderm of the intact embryo, these induced primary neurons have sensory characteristics with no upregulation of motor neuron markers. In contrast, xNgn2 is able to up-regulate both sensory and motor neuron markers in naïve ectoderm of animal cap explants, suggesting a non-permissive environment for motor identity in the patterned ectoderm of the whole embryo.
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Wang, Xiao-Jing, Yinghui Liu, Maria V. Sanchez-Vives, and David A. McCormick. "Adaptation and Temporal Decorrelation by Single Neurons in the Primary Visual Cortex." Journal of Neurophysiology 89, no. 6 (June 2003): 3279–93. http://dx.doi.org/10.1152/jn.00242.2003.

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Limiting redundancy in the real-world sensory inputs is of obvious benefit for efficient neural coding, but little is known about how this may be accomplished by biophysical neural mechanisms. One possible cellular mechanism is through adaptation to relatively constant inputs. Recent investigations in primary visual (V1) cortical neurons have demonstrated that adaptation to prolonged changes in stimulus contrast is mediated in part through intrinsic ionic currents, a Ca2+-activated K+ current ( IKCa) and especially a Na+-activated K+ current ( IKNa). The present study was designed to test the hypothesis that the activation of adaptation ionic currents may provide a cellular mechanism for temporal decorrelation in V1. A conductance-based neuron model was simulated, which included an IKCa and an IKNa. We show that the model neuron reproduces the adaptive behavior of V1 neurons in response to high contrast inputs. When the stimulus is stochastic with 1/ f 2 or 1/ f-type temporal correlations, these autocorrelations are greatly reduced in the output spike train of the model neuron. The IKCa is effective at reducing positive temporal correlations at approximately 100-ms time scale, while a slower adaptation mediated by IKNa is effective in reducing temporal correlations over the range of 1–20 s. Intracellular injection of stochastic currents into layer 2/3 and 4 (pyramidal and stellate) neurons in ferret primary visual cortical slices revealed neuronal responses that exhibited temporal decorrelation in similarity with the model. Enhancing the slow afterhyperpolarization resulted in a strengthening of the decorrelation effect. These results demonstrate the intrinsic membrane properties of neocortical neurons provide a mechanism for decorrelation of sensory inputs.
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Dissertations / Theses on the topic "Primary neuron"

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Zanini, Marco. "Ciliogenesis Control Mechanisms in Cerebellar Neuron Progenitors." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS475/document.

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Pendant le développement du cervelet, les progéniteurs des neurones granulaires (PNG) nécessitent la présence du cil primaire pour proliférer en réponse à Sonic Hedgehog (SHH). En effet, la prolifération dérégulée des PNGs peut conduire à la formation d'une tumeur pédiatrique maligne appelée SHH-médulloblastome (MB), de ce fait comprendre comment le cil primaire est régulé dans les PNGs est crucial.Nous montrons que le facteur de transcription Atoh1 contrôle la présence du cil primaire dans les PNGs in vitro et in vivo. En particulier, la suppression du cil primaire par l’inactivation génétique de gènes impliqués dans la ciliogenèse (par exemple, Kif3a ou Ift88) empêche Atoh1 de maintenir les PNGs en prolifération, ce qui indique qu’Atoh1 favorise l’expansion des PNGs en maintenant la présence du cil primaire. D’un point de vue moléculaire, Atoh1 contrôle la formation du cil primaire en régulant le bon positionnement peri-centrosomal des satellites centriolaires (SC), complexes protéiques essentiels pour la ciliogenèse. L'inactivation de Atoh1 dans les PNGs perturbe en effet la distribution subcellulaire des SCs, altérant ainsi inévitablement la ciliogenèse. Cette nouvelle fonction de Atoh1 est gouvernée par la régulation transcriptionnelle directe d'un composant clé des SCs, Cep131. L’expression ectopique de Cep131 dans les PNGs restore les effets liés à l'inactivation d'Atoh1, rétablissant la localisation correcte du SC et comme conséquence la présence d’un cil primaire.De plus, nous avons montré que cette voie Atoh1-SC-cil primaire-SHH contrôlant la prolifération des PNGs est également conservée dans le contexte du SHH-MB, où Atoh1 est surexprimée et essentielle pour sa formation et sa maintenance.Ces données révèlent un mécanisme par lequel la ciliogenèse est régulée dans des progéniteurs de neurones, offrant de nouvelles informations sur la neurogenèse dans le cervelet et sur la pathogenèse du SHH-MB
Cerebellar granule neuron progenitors (GNPs) require the primary cilium to proliferate in response to Sonic Hedgehog (SHH) during cerebellar development. As aberrant proliferation of GNPs may lead to SHH-type medulloblastoma (SHH-MB), a pediatric brain tumor, understanding which mechanisms control ciliogenesis in GNPs represents a major interest in the field. Here, we show that the proneural bHLH transcription factor Atoh1 controls the presence of primary cilia in GNPs both in vitro and in vivo, thus maintaining GNPs responsive to the mitogenic effects of SHH. Indeed, loss of primary cilia induced via knockdown of specific ciliary components (e.g. Kif3a and Ift88) abolishes the ability of Atoh1 to keep GNPs in proliferation in vivo. Mechanistically, Atoh1 controls ciliogenesis by regulating the proper peri-centrosomal clustering of centriolar satellites (CS), large multiprotein complexes working as essential machineries for ciliogenesis. Knockdown of Atoh1 in GNPs perturbs CS subcellular distribution, leading to impairment of ciliogenesis. Luciferase reporter assays and chromatin immunoprecipitation experiments indicate that Atoh1 can directly regulate the expression of Cep131, a key CS core component. Importantly, ectopic expression of Cep131 in GNPs depleted of Atoh1, is sufficient to restore proper CS localization and consequent primary cilia formation, indicating that the Atoh1-Cep131-CS axis is responsible for ciliogenesis in GNPs.In addition, we further demonstrated that these functions of Atoh1 are conserved in the context of SHH-MB, where Atoh1 is typically overexpressed and acts as a lineage-dependent transcription factor.These data reveal a mechanism whereby ciliogenesis is regulated in neuron progenitors providing novel insights into cerebellar neurogenesis and pathogenesis of SHH-MB
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Houlton, R. E. "Influence of adaptation on single neuron and population coding in mouse primary visual cortex." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1417573/.

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In the visual system, prolonged exposure to a high contrast stimulus leads to a decrease in neuronal responsiveness, referred to as contrast adaptation. Contrast adaptation has been extensively studied in carnivores and primates, but has so far received little attention in mice. This thesis explores contrast adaptation and its mechanisms in mouse primary visual cortex (V1). Using extracellular tetrode recordings in mouse V1, I found contrast adaptation to be orientation unspecific. While this finding differs from reports in carnivores and primates, it is consistent with the notion that responsiveness of individual neurons is influenced by the activity history of the local network. Adaptation was also found to be cell-type specific, as putative parvalbumin (PV) expressing interneurons underwent less adaptation than other cell types. There is debate whether adaptation arises within the cortex or is inherited from the earlier stages in the visual pathway (e.g. visual thalamus or retina). In order to assess the relative contributions of cortical/subcortical mechanisms towards adaptation in mouse V1, I used optogenetic methods to suppress cortical activity (via activation of Channelrhodopsin-2 in PV interneurons) during an adapting stimulus. Suppressing cortical activity, and hence any activity-dependent cortical mechanisms, largely counteracted the effects of adaptation on neuronal responsiveness, consistent with a substantial cortical component of adaptation. Interestingly, whilst adaptation reduced both contrast and response gain, only the latter effect was influenced by cortical suppression. This suggests that the mechanisms mediating adaptation-induced alterations in contrast and response gain are different, and possibly occur at different loci within the visual pathway. The consequences of adaptation on V1 population responses were explored with two-photon calcium imaging. Adaptation to dynamic stimuli of multiple orientations caused a divisive scaling of responses, consistent with a reduction in response gain. Adaptation also decorrelated neuronal activity, leading to sparser and more distributed stimulus representations across the population. Whole-cell recordings further revealed that these effects were associated with decreased membrane depolarisation, and an increase in membrane potential variability.
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Lewis, Sara Ann. "Functions of Drosophila Pak (p21-activated kinase) in Morphogenesis: A Mechanistic Model based on Cellular, Molecular, and Genetic Studies." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/594389.

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Intellectual disability (ID) is a common phenotype of brain-development disorders and is heterogeneous in etiology with numerous genetic causes. PAK3 is one gene with multiple mutations causing ID. Affected individuals have microcephaly, and other brain-structure defects have been reported. Additionally, PAK3 is in a genetic network with eighteen other genes whose mutations cause ID, suggesting the molecular mechanisms by which PAK3 regulates of cognitive function may be shared by other genetic ID disorders. Studies in rodent models have shown that the orthologs of PAK3 are important for regulating dendrite spine morphology and postnatal brain size. In Drosophila melanogaster, the morphological processes of oogenesis, dorsal closure during embryogenesis, and salivary gland-lumen formation require Pak, the Drosophila ortholog of PAK3. Additionally, Pak is important for development of the subsynaptic reticulum of the neuromuscular junction, sensory axon pathfinding and terminal arborization in the Drosophila central nervous system (CNS). However, the role of Pak in mushroom body (MB) structure and intrinsic neurite arbor morphogenesis, as well as details of the underlying cellular and molecular mechanisms are unknown. To address this gap, I used Drosophila models of PAK3 gene mutations, Pak, and a combination of immunostaining, primary cell culture, and genetic interaction studies to elucidate these mechanisms. I performed a detailed characterization of the previously reported adult Pak phenotypes of decreased survival as well as leg and wing morphology. I found that decreased survival is a low-penetrance phenotype that is enhanced by chromosomes from the same mutagenesis. Defects of the adult wing include folding and misalignment between the layers, blisters, and missing or partial cross veins. The Pak-mutant legs are short and often misdirected in the pupal case with morphological defects in the shape of the leg segments themselves. The mushroom bodies are important insect learning and memory brain structures whose lobes are composed of axon bundles with individual axons bifurcating to form the α and β lobes. Mutations in Pak cause defects in the length, thickness, and direction of the MB α and β lobes. These defects increase in severity during metamorphosis, when neurogenesis and differentiation of these structures occur, suggesting that Pak stabilizes the branches of the α/β mushroom body neurons. Pak-mutant cultured neurons have reduced neurite arbor size with defects in neurite caliber. Initial outgrowth was normal, followed by a decrease in neurite branch number, again supporting the role of Pak in neurite-branch stability. There are defects in the cytoskeleton in growth cones at six hours post-plating as well as in neurons after three days in vitro. The Pak-mutant phenotype severity depends on the phosphorylation status of myosin regulatory light chain, supporting the mechanistic hypothesis that Pak regulates neurite-branch stability by inhibiting myosin light chain kinase. The neuronal phenotype of decreased branch stability suggests a mechanism of excessive retraction as the cellular pathogenesis underlying PAK3 mutation-associated brain disorders. I used western blotting to characterize the protein products of four nonsense mutations in Drosophila Pak to interpret genotype-phenotype relationships. Each allele has molecularly unique consequences: Pak¹¹, stop-codon read through and truncated protein; Pak¹⁶, no read through, but truncated protein; Pak⁶, read through with no truncated protein; Pak ¹⁴, neither readthrough nor truncated protein. Truncated proteins produced by Pak¹¹ and Pak¹⁶ alleles retained partial function for survival, wing blistering, leg morphology, and neurite length. Conversely, truncated protein increased the severity of the mushroom body defects. Truncated proteins have no effect on neuron branch number, wing folding, or vein defects. Together, these results demonstrate a role of Pak in regulating epithelial morphology, brain structure, and neurite arbor size and complexity. These closely resemble features of the human disorder, providing evidence that this is a good genetic model for this cause of ID.
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DI, BIASE ERIKA. "GM1 OLIGOSACCHARIDE ACCOUNTS FOR GM1 ROLE IN ENHANCING NEURONAL DEVELOPMENT ACTING ON TRKA-MAPK PATHWAY." Doctoral thesis, Università degli Studi di Milano, 2019. http://hdl.handle.net/2434/692335.

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Il ganglioside GM1 è un glicosfingolipide mono-sialilato presente nello strato esterno della membrana plasmatica cellulare ed è particolarmente abbondante nei neuroni. Numerosi studi in vitro e in vivo evidenziano il ruolo del GM1 non solo come componente strutturale ma anche come regolatore di diversi processi cellulari. Infatti, l'arricchimento di GM1 nei microdomini di membrana promuove il differenziamento e la protezione neuronale. Inoltre il contenuto di GM1 è essenziale per la sopravvivenza e il mantenimento dei neuroni. Nonostante vi siano numerose evidenze sugli effetti neuronotrofici mediati dal GM1, la conoscenza del meccanismo d'azione sottostante è scarsa. Recentemente, la catena oligosaccaridica del GM1 (oligoGM1) è stata identificata come responsabile delle proprietà neuritogeniche del ganglioside GM1 nelle cellule di neuroblastoma. Gli effetti mediati dall’oligoGM1 dipendono dal suo legame con il recettore specifico dell’ NGF, il TrkA, determinando così l'attivazione della via TrkA-MAPK. In questo contesto, il mio lavoro di dottorato mirava a confermare il ruolo dell’oligoGM1, come componente bioattiva dell’intero ganglioside GM1, capace di stimolare i processi di differenziaziamento e maturazione dei neuroni granulari cerebellari di topo. Come prima cosa, abbiamo eseguito analisi morfologiche in time -course sui neuroni primari coltivati in presenza o in assenza dei gangliosidi GM1 o GD1a (il quale rappresenta il diretto precursore catabolico del GM1), somministrati esogenamente. Abbiamo osservato che entrambi i gangliosidi aumentavano l’aggregazione e l'arborizzazione dei neuroni. Dopo successiva somministrazione dei rispettivi oligosaccaridi, abbiamo osservato che solo l’oligoGM1 favoriva la migrazione dei neuroni, mentre l’oligoGD1a non induceva nessun effetto discriminante rispetto alle cellule controllo. Questo risultato suggerisce l'importanza della specifica struttura saccaridica del GM1 nella mediazione degli effetti neuronotrofici del ganglioside. Quindi abbiamo caratterizzato biochimicamente l'effetto mediato dall’oligoGM1 nei neuroni e abbiamo osservato un più elevato tasso di fosforilazione delle proteine FAK e Src, le quali rappresentano i regolatori intracellulari chiave della motilità neuronale. Inoltre, in presenza dell’ oligoGM1 i neuroni granulari cerebellari mostravano un aumento del livello di marcatori neuronali specifici (ad es. β3-Tubulina, Tau, Neuroglicano C, Sinapsina), suggerendo uno stadio di maturazione più avanzato rispetto ai controlli. Inoltre, abbiamo scoperto che l'oligoGM1 accelera l'espressione del pattern di gangliosidi tipico dei neuroni maturi che è caratterizzato da alti livelli di gangliosidi complessi (cioè GM1, GD1a, GD1b e GT1b) e basso livello del ganglioside più semplice GM3. Per studiare il meccanismo d'azione dell'oligoGM1, abbiamo usato il suo derivato marcato con il trizio e abbiamo scoperto che l'oligoGM1 interagisce con la superficie cellulare senza entrare nelle cellule. Questa scoperta suggerisce la presenza di un bersaglio biologico sulla membrana plasmatica neuronale. È interessante notare che abbiamo riscontrato una precoce attivazione della via di segnalazione del TrkA associata alle MAP chinasi in seguito alla somministrazione dell’oligoGM1 nelle culture neuronali. Questo risultato suggerisce che questo evento rappresenti un punto di partenza degli effetti dell’ oligoGM1 nei neuroni. I nostri dati rivelano che gli effetti del ganglioside GM1 sul differenziamento e la maturazione neuronale sono mediati dalla sua porzione di oligosaccaride. Infatti, l’oligoGM1 interagisce con la superficie cellulare, innescando così l'attivazione di processi biochimici intracellulari che sono responsabili della migrazione neuronale, dell'emissione dei dendriti e della crescita degli assoni. Nel complesso, i nostri risultati sottolineano l'importanza dell’ oligoGM1 come un nuovo e promettente fattore neurotrofico.
The GM1 ganglioside is a mono-sialylated glycosphingolipid present in the outer layer of the cell plasma membrane and abundant in neurons. Numerous in vitro and in vivo studies highlight the role of GM1 not only as a structural component but also as a functional regulator. Indeed, GM1 enrichment in membrane microdomains promotes neuronal differentiation and protection, and the GM1 content is essential for neuronal survival and maintenance. Despite many lines of evidence on the GM1-mediated neuronotrophic effects, our knowledge on the underlying mechanism of action is scant. Recently, the oligosaccharide chain of GM1 (oligoGM1) has been identified as responsible for the neuritogenic properties of the GM1 ganglioside in neuroblastoma cells. The oligoGM1-mediated effects depend on its binding to the NGF specific receptor TrkA, thus resulting in the TrkA-MAPK pathway activation. In this context, my PhD work aimed to confirm the role of the oligoGM1, as the bioactive portion of the entire GM1 ganglioside, capable of enhancing the differentiation and maturation processes of mouse cerebellar granule neurons. First, we performed time course morphological analyses on mouse primary neurons plated in the presence or absence of exogenously administered gangliosides GM1 or GD1a (direct GM1 catabolic precursor). We found that both gangliosides increased neuron clustering and arborization, however only oligoGM1 and not oligoGD1a induced the same effects in prompting neuron migration. This result suggests the importance of the specific GM1 saccharide structure in mediating neuronotrophic effects. Then we characterized biochemically the oligoGM1-mediated effect in mouse primary neurons, and we observed a higher phosphorylation rate of FAK and Src proteins which are the intracellular key regulators of neuronal motility. Moreover, in the presence of oligoGM1 cerebellar granule neurons showed increased level of specific neuronal markers (e.g., β3-Tubulin, Tau, Neuroglycan C, Synapsin), suggesting an advanced stage of maturation compared to controls. In addition, we found that the oligoGM1 accelerates the expression of the typical ganglioside pattern of mature neurons which is characterized by high levels of complex gangliosides (i.e., GM1, GD1a, GD1b, and GT1b) and low level of the simplest one, the GM3 ganglioside. To study the mechanism of action of the oligoGM1, we used its tritium labeled derivative and we found that the oligoGM1 interacts with the cell surface without entering the cells. This finding suggests the presence of a biological target at the neuronal plasma membrane. Interestingly, we observed the TrkA-MAP kinase pathway activation as an early event underlying oligoGM1 effects in neurons. Our data reveal that the effects of GM1 ganglioside on neuronal differentiation and maturation are mediated by its oligosaccharide portion. Indeed, oligoGM1 interacts with the cell surface, thus triggering the activation of intracellular biochemical pathways that are responsible for neuronal migration, dendrites emission and axon growth. Overall, our results point out the importance of oligoGM1 as a new promising neurotrophic player.
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Vieira, Diogo Porfirio de Castro. "Análises de estabilidade e de sensibilidade de modelos biologicamente plausíveis do córtex visual primário." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-18032009-163830/.

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A neurociência computacional é uma vasta área que tem como objeto de estudo o entendimento ou a emulação da dinâmica cerebral em diversos níveis. Neste trabalho atenta-se ao estudo da dinâmica de neurônios, os quais, no consenso atual, acredita-se serem as unidades fundamentais do processamento cerebral. A importância do estudo sobre o comportamento de neurônios se encontra na diversidade de propriedades que eles podem apresentar. O estudo se torna mais rico quando há interações de sistemas internos ao neurônio em diferentes escalas de tempo, criando propriedades como adaptação, latência e comportamento em rajada, o que pode acarretar em diferentes papéis que os neurônios podem ter na rede. Nesta dissertação é feita uma análise sob o ponto de vista de sistemas dinâmicos e de análise de sensibilidade de seis modelos ao estilo de Hodgkin-Huxley e compartimentais de neurônios encontrados no córtex visual primário de mamíferos. Esses modelos correspondem a seis classes eletrofisiológicas de neurônios corticais e o estudo feito nesta dissertação oferece uma contribuição ao entendimento dos princípios de sistemas dinâmicos subjacentes a essa classificação.
Computational neuroscience is a vast scientific area which has as subject of study the unsderstanding or emulation of brain dynamics at different levels. This work studies the dynamics of neurons, which are believed, according to present consensus, to be the fundamental processing units of the brain. The importance of studying neuronal behavior comes from the diversity of properties they may have. This study becomes richer when there are interactions between distintic neuronal internal systems, in different time scales, creating properties like adaptation, latency and bursting, resulting in different roles that neurons may have in the network. This dissertation contains a study of six reduced compartmental conductance-based models of neurons found in the primary visual cortex of mammals under the dynamical systems and sensitivity analysis viewpoints. These models correspond to six eletrophysiological classes of cortical neurons and this dissertation offers a contribution to the understanding of the dynamical-systems principles underlying such classification.
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Fellows, Matthew R. "Spatiotemporal tuning for position and velocity in primate primary motor cortex neurons /." View online version; access limited to Brown University users, 2005. http://wwwlib.umi.com/dissertations/fullcit/3174598.

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Gaffuri, Anne-Lise. "Drosophila melanogaster, as a model system to study the cell biology of neuronal GPCRs." Thesis, Paris 5, 2012. http://www.theses.fr/2012PA05T063.

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Le récepteur cannabinoique de type 1 (CB1R) est l’un des récepteurs couplés aux protéines G les plus abondants du cerveau mammifère. CB1R a longtemps été décrit comme un récepteur présynaptique régulant de manière rétrograde la transmission synaptique. Cependant, depuis les vingt dernières années, de nouveaux rôles ont été découverts et il est maintenant clairement admis que l’action des endocannabinoides (eCBs) ne se limite pas à la régulationde la neurotransmission au niveau de synapses adultes déjà établies. En effet, les eCBs et le CB1R sont des acteurs majeurs de l’ensemble des phases du développement cérébral. Cependant, les mécanismes moléculaires impliqués n’ont toujours pas été identifiés. Les mécanismes cellulaires auxquels nous nous intéressons ne dépendant pas de l’environnement cellulaire, nous proposons donc de combiner la puissance génétique du modèle drosophile à l’accessibilité et la haute résolution offerte par la culture primaire de neurones. De plus, le récepteur CB1 ne possédant pas d’orthologue parmi les invertébrés, ce système offre la possibilité d’étudier la biologie du récepteur en s’affranchissant de la machinerie endocannabinoide. Cependant, actuellement, aucun protocole de culture primaire de neurones de drosophile ne permet d’obtenir des cellules hautement différenciées et polarisées à basse densité. Ainsi, nous avons tout d’abord développé, optimisé et validé un nouveau protocole permettant de d’obtenir des neurones fonctionnels, hautement différenciés et polarisés en culture de basse densité. Dans un second temps, nous avons démontré que l’activation durécepteur CB1, exprimé ectopiquement dans les neurones de drosophile, entrainait son internalisation, de manière identique à ce qui avait déjà été observé chez les mammifères. Puis, nous avons étudié l’effet de l’expression et de l’activation ectopique de CB1R sur le développement neuronal chez la drosophile. Ainsi, nous avons démontré que l’activation du récepteur module directement la dendritogénèse. Afin de compléter la caractérisation de notremodèle, nous avons démontré que l’activation transitoire du récepteur dans les corps pédonculés (le centre de la mémoire olfactive chez la drosophile) altérait spécifiquement la formation d’une forme consolidée de mémoire après un conditionnement aversif. En conclusion, la validation du modèle drosophile dans l’étude de la biologie cellulaire durécepteur CB1 ouvre de nouvelles perspectives quant à la détermination des mécanismes moléculaires régissant l’action du récepteur sur le fonctionnement neuronal
The type-1 cannabinoid receptor (CB1R), the neuronal receptor for the major psychoactive substance of marijuana, is one, of the most abundant G-protein coupled receptors in the mammalian central nervous system. CB1R is traditionally described as a presynaptic receptor that retrogradely regulates synaptic transmission. In addition to this now relatively wellcharacterized function, in the last two decades it has become widely recognized that endocannabinoid (eCB) actions in the brain are not limited to the regulation of neurotransmission at established adult synapses. Indeed, eCB and CB1R are now recognized to be involved in brain development at the synaptic, neuronal and network levels. However, precise mechanisms underlying these processes remain poorly described. Since cellular mechanisms that mediate CB1R-activition dependent neuronal remodeling and subneuronal targeting have been demonstrated to be cell-autonomous, we aimed to combine the power of Drosophila genetics with the experimental accessibility and single-cell resolution of lowdensity primary neuronal cultures, a tool currently lacking in Drosophila. Moreover, becauseDrosophila does not have a CB1R ortholog, CB1R cell biology may be observed independently from eCB machinery. Thus, we first developed and validated an in vitro culture protocol that yields mature and fully differentiated Drosophila neurons. Secondly, we showed that activation-dependent endocytosis of ectopically expressed CB1R is conserved in Drosophila neurons. Next, we investigated whether ectopic expression and activation of CB1R in Drosophila modulate neuronal development. As observed in mammals, we observed that activation of CB1R impairs dendritogenesis in a cell-autonomous manner. For further characterization of our model, we showed that, as with mammals, transient ectopic CB1R expression and activation in mushroom body neurons (the center of olfactory memory in Drosophila) modulate the formation of a consolidated form of aversive memory. In conclusion, the validation of this new animal model opens new perspectives to better characterize mechanisms underlying modulation of neuronal functions induced by CB1Ractivity
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Sprague, Jared Michael. "TRPV1 Sensitization in Primary Sensory Neurons." Thesis, Harvard University, 2014. http://dissertations.umi.com/gsas.harvard:11441.

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Pain is a major personal and community burden throughout the world with currently limited treatment options for persistent pain due to unacceptable side effects, dependence or frank inefficacy. It is necessary to understand the anatomical and molecular pathways leading to pain to better cope with the current challenge of treating it.
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McCue, Michael Patrick. "Acoustic responses from primary vestibular neurons." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/17330.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Whitaker College of Health Sciences and Technology, 1993.
Includes bibliographical references (leaves 93-99).
by Michael Patrick McCue.
Ph.D.
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Ruffo, Mark. "The role of the corticothalamic projection in the primate motor thalamus /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/10626.

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Books on the topic "Primary neuron"

1

Zenker, Wolfgang, and Winfried L. Neuhuber, eds. The Primary Afferent Neuron. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0579-8.

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1925-, Zenker W., and Neuhuber Winfried L, eds. The Primary afferent neuron: A survey of recent morpho-functional aspects. New York: Plenum Press, 1990.

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T, Thomas D. G., ed. Neuro-oncology: Primary malignant brain tumors. Baltimore: Johns Hopkins University Press, 1990.

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T, Thomas David G., ed. Neuro-oncology: Primary malignant brain tumours. London: Edward Arnold, 1990.

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Dabdoub, Alain, Bernd Fritzsch, Arthur N. Popper, and Richard R. Fay, eds. The Primary Auditory Neurons of the Mammalian Cochlea. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3031-9.

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Complex Encoding of Olfactory Information by Primary Sensory Neurons. [New York, N.Y.?]: [publisher not identified], 2020.

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A, Twijnstra, Keyser A, and Ongerboer de Visser, B. W., eds. Neuro-oncology: Primary tumors and neurological complications of cancer. Amsterdam: Elsevier, 1993.

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Montreal Neurological Hospital. Nursing Education Committee. Neuro nursing handbook: Four primary concerns: increased intracranial pressure, seizures, mobility loss, communication disorders. Edited by MacMillan Mary Irene and Robertson Caroline. [Montreal]: Montreal Neurological Hospital Nursing Department, 1988.

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Edwards, Clare M. The roles of central neural and local factors in primary Raynaud's disease. Birmingham: University of Birmingham, 1998.

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Der Anscheinsbeweis der Kausalität: Unter besonderer Berücksichtigung der neueren Rechtsprechung. Frankfurt am Main: P. Lang, 1994.

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Book chapters on the topic "Primary neuron"

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Akeson, Richard A. "Primary Olfactory Neuron Subclasses." In Molecular Neurobiology of the Olfactory System, 297–318. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4613-0989-5_13.

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Andres, K. H., and M. v Düring. "Comparative and Functional Aspects of the Histological Organization of Cutaneous Receptors in Vertebrates." In The Primary Afferent Neuron, 1–17. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0579-8_1.

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Davies, Alun M. "The Development of Primary Sensory Neurons." In The Primary Afferent Neuron, 109–17. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0579-8_10.

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Droz, B., I. Barakat, J. Kazimierczak, E. Philippe, and A. Rochat. "Remodeling of Neuronal Subpopulations in Dorsal Root Ganglion: Role of Chemical Factors and Intercellular Contacts." In The Primary Afferent Neuron, 119–25. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0579-8_11.

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Weihe, Eberhard. "Neuropeptides in Primary Afferent Neurons." In The Primary Afferent Neuron, 127–59. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0579-8_12.

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Molander, C., and G. Grant. "On the Organization of Cutaneous and Muscle Nerve Projections in the Rat Lumbar Dorsal Horn." In The Primary Afferent Neuron, 161–72. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0579-8_13.

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Neuhuber, Winfried L., Wolfgang Zenker, and Sergei Bankoul. "Central Projections of Cervical Primary Afferents in the Rat. Some General Anatomical Principles and their Functional Significance." In The Primary Afferent Neuron, 173–88. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0579-8_14.

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Neuhuber, Winfried L., and Dominique Irminger. "Visceral Afferent Projections to the Thoracolumbar Spinal Cord in Normal and Capsaicin-Treated Rats." In The Primary Afferent Neuron, 189–99. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0579-8_15.

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Mense, S. "Relationship between Functional and Morphological Properties in Single Primary Afferent Neurons." In The Primary Afferent Neuron, 201–11. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0579-8_16.

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Réthelyi, M. "Ultrastructure of Primary Afferent Terminals in the Spinal Cord." In The Primary Afferent Neuron, 213–25. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0579-8_17.

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Conference papers on the topic "Primary neuron"

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Michel, C., R. Nouvian, C. Azevedo-Coste, J. L. Puel, and J. Bourien. "A computational model of the primary auditory neuron activity." In 2010 32nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC 2010). IEEE, 2010. http://dx.doi.org/10.1109/iembs.2010.5626273.

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Peng, Wang, Xu Jie, Li Xin, He Xin, Li Yaohua, and Yu Shun. "Study on effect of α-Synuclein enhanced survival rate of rat primary cultured neuron." In 2011 International Conference on Human Health and Biomedical Engineering (HHBE). IEEE, 2011. http://dx.doi.org/10.1109/hhbe.2011.6028372.

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Flunkert, Stefanie, Tina Loeffler, Benedikt Fabry, Hoa Huu Phuc Nguyen, Robert Wronski, and Birgit Hutter-Paier. "B07 Metabolic characteristics of primary neuron cultures from bachd rats compared to induced lesion models." In EHDN 2018 Plenary Meeting, Vienna, Austria, Programme and Abstracts. BMJ Publishing Group Ltd, 2018. http://dx.doi.org/10.1136/jnnp-2018-ehdn.59.

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Xia, Jiucheng, Ting Long, and Danian Qin. "THE DIFFERENT DOSE EFFICIENCY OF LEPTIN TO NG108-15 CELL LINE AND PRIMARY HYPOTHALAMIC NEURON OF MOUSE." In 2016 International Conference on Biotechnology and Medical Science. WORLD SCIENTIFIC, 2016. http://dx.doi.org/10.1142/9789813145870_0062.

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Gonçalo, Ana Clara Mota, and Kaline dos Santos Kishishita Castro. "Treatment and main complications of Amyotrophic Lateral Sclerosis: a literature review." In XIII Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2021. http://dx.doi.org/10.5327/1516-3180.520.

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Background: Greek, the word sklerosis means hardening. In medicine, the term sclerosis refers to the stiffening of body tissues - scars. These scars (sclerosis), when located in motor neurons, are signs of Amyotrophic Lateral Sclerosis (ALS), a neurodegenerative disease that affects neurons located in the primary motor cortex, brain stem, spinal cord and pyramidal tract. ALS has no cure and its treatment options are currently limited. Objectives: Review on the major complications of ALS, as well as the therapeutic methods for its treatment. Methods: Study conducted trough articles found on The New English Journal of Medicine, SpringerLink and Scholar Google and dated between 2009 and 2021. Results: ALS is known for the gradual atrophy of the muscle fibers associated with muscle loss, dysarthria and dysphagia complicated by sialorrhea, depending on the condition. All forms of the disease lead to paralysis, which causes the main consequent complication for the early mortality of patients - respiratory failure. The treatment of ALS has only one specific approved drug: riluzole, which decreases motor neuron damage, reducing disease progression and increasing patient survival. New therapeutic methods are being studied, such as treatment with stem cells and STING- induced inflammation, but they remain with limited evidence. Conclusions: ALS still has extremely restricted targeted treatment. There’s evident need for further studies aimed at a greater understanding of therapies with the potential to become effective in delaying the progression of the disease.
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Chaplygina, A. V., V. I. Kovalev, D. Y. Zhdanova, and N. V. Bobkova. "CHEMICAL CONVERSION OF PRIMARY NEURONAL CULTURES." In NOVEL TECHNOLOGIES IN MEDICINE, BIOLOGY, PHARMACOLOGY AND ECOLOGY. Institute of information technology, 2022. http://dx.doi.org/10.47501/978-5-6044060-2-1.389-393.

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The paper discusses the use of direct chemical transformation of glial cells into neurons to solve the problems of neurodegenerative diseases. Original experimental data on the success-ful use of a conversion cocktail for astrocyte-neuronal conversion in a primary cell culture of the 5xFAD mouse hippocampus are presented.
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Ananiev, S. S., D. A. Pavlov, R. N. Yakupov, V. A. Golodnova, and M. V. Balykin. "The effect of transcranial magnetic stimulation on the excitability of the motor neuron pools of the muscles of the lower extremities." In VIII Vserossijskaja konferencija s mezhdunarodnym uchastiem «Mediko-fiziologicheskie problemy jekologii cheloveka». Publishing center of Ulyanovsk State University, 2021. http://dx.doi.org/10.34014/mpphe.2021-8-11.

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The study was conducted on 22 healthy men aged 18-23 years. The primary motor cortex innervating the lower limb was stimulated with transcranial magnetic stimulation. Using transcutaneous electrical stimulation of the spinal cord, evoked motor responses of the muscles of the lower extremities were initiated when electrodes were applied cutaneous between the spinous processes in the Th11-Th12 projection. Research protocol: Determination of the thresholds of BMO of the muscles of the lower extremities during TESCS; determination of the BMO threshold of the TA muscle in TMS; determination of the thresholds of the BMO of the muscles of the lower extremities during TESCS against the background of 80% and 90% TMS. It was found that magnetic stimulation of the motor cortex of the brain leads to an increase in the excitability of the neural structures of the lumbar thickening of the spinal cord and an improvement in neuromuscular interactions. Key words: transcranial magnetic stimulation, transcutaneous electrical stimulation of the spinal cord, neural networks, excitability, neuromuscular interactions.
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Allen, Kathleen B., and Bradley E. Layton. "Mechanical Neural Growth Models." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-79445.

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Critical to being able to control the growth patterns of cell-based sensors is being able to understand how the cytoskeleton of the cell maintains its structure and integrity both under mechanical load and in a load-free environment. Our approach to a better understanding of cell growth is to use a computer simulation that incorporates the primary structures, microtubules, necessary for growth along with their observed behaviors and experimentally determined mechanical properties. Microtubules are the main compressive structural support elements for the axon of a neuron and are created via polymerization of α-β tubulin dimers. Our de novo simulation explores the mechanics of the forces between microtubules and the membrane. We hypothesize that axonal growth is most influenced by the location and direction of the force exerted by the microtubule on the membrane, and furthermore that the interplay of forces between microtubules and the inner surface of the cell membrane dictates the polar structure of axons. The simulation will be used to understand cytoskeletal mechanics for the purpose of engineering cells to be used as sensors.
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Vijayakumaran, P. M., C. P. Nagaraj, C. Paramasivan Pillai, R. Ramakrishnan, and M. Sivaramakrishna. "Nuclear Instrumentation Systems in Prototype Fast Breeder Reactor." In 12th International Conference on Nuclear Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/icone12-49354.

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The nuclear instrumentation systems of the Prototype Fast Breeder Reactor (PFBR) primarily comprise of global Neutron Flux Monitoring, Failed Fuel Detection & Location, Radiation Monitoring and Post-Accident Monitoring. High temperature fission chambers are provided at in-vessel locations for monitoring neutron flux. Failed fuel detection and location is by monitoring the cover gas for fission gases and primary sodium for delayed neutrons. Signals of the core monitoring detectors are used to initiate SCRAM to protect the reactor from various postulated initiating events. Radiation levels in all potentially radioactive areas are monitored to act as an early warning system to keep the release of radioactivity to the environment and exposure to personnel well below the permissible limits. Fission Chambers and Gamma Ionisation Chambers are located in the reactor vault concrete for monitoring the neutron flux and gamma radiation levels during and after an accident.
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Sasoglu, F. Mert, Devrim Kilinc, Kathleen Allen, and Bradley Layton. "Parallel Force Measurement in Cell Arrays." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42472.

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The primary goal of this work is to establish a robust, repeatable method for growing forebrain nerve cells in a parallel manner by stretching them using a microfabricated PDMS beam array and printing arrays of neurons. The highly compliant, transparent, biocompatible PDMS micro beam array may offer a method for more rapid throughput in cell and protein mechanics force measurement experiments with sensitivities necessary for highly compliant structures such as axons. This work has two endpoints. One is to use a neural array as an experimental testbed for investigating neuronal cell growth hypotheses. The other endpoint is to build a neuronal-based, biosensor device capable of acting as a cell-based sensor. We present preliminary results for microbeams attaching to nerve cells. The attachment ratio the life-length and the axon lengths of the chick forebrain cells on microprinted spots will also be compared with an equivalent protein coated area of cells.
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Reports on the topic "Primary neuron"

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Wiggins, Vince L., Larry T. Looper, and Sheree K. Engquist. Neural Networks: A Primer. Fort Belvoir, VA: Defense Technical Information Center, May 1991. http://dx.doi.org/10.21236/ada235920.

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Schneider, E. A. A station blackout simulation for the Advanced Neutron Source Reactor using the integrated primary and secondary system model. Office of Scientific and Technical Information (OSTI), June 1994. http://dx.doi.org/10.2172/10159090.

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Depireux, Didier A., Jonathan Z. Simon, David J. Klein, and Shihab A. Shamma. Dynamics of Neural Responses in Ferret Primary Auditory Cortex: I. Spectro-Temporal Response Field Characterization by Dynamic Ripple Spectra. Fort Belvoir, VA: Defense Technical Information Center, January 1999. http://dx.doi.org/10.21236/ada439778.

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Xin, Wu, and Xue Tao. The efficacy and safety of neuromodulation in refractory epilepsy: a systematic review and network meta-analysis. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, April 2022. http://dx.doi.org/10.37766/inplasy2022.4.0042.

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Review question / Objective: To assess the efficacy and safety of different neuromodulation applied to the refractory epilepsy and provide a better choice for clinical practice. Condition being studied: Epilepsy is a frequent neurologic illness defined by bursts of hypersynchronized neural network activity that afflict about 1% of the global population. Unfortunately, roughly 30% of people with drug-resistant epilepsy (DRE) continue to experience seizures despite three anti-seizure drugs. In most cases, resective surgery, as the first-line treatment for DRE, is considered a curative therapy for achieving long-term seizure-free status, but about half of patients are not candidates for surgery due to a variety of factors such as multiple/diffuse/widespread seizure foci, epileptic foci arising from eloquent, primary generalized epilepsy, or patients unwilling to undergo surgery. Neuromodulation, albeit palliative, is an important alternative treatment for these individuals to prevent or decrease ictal episodes, which can affect the nervous system in a variety of ways.
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Engel, Bernard, Yael Edan, James Simon, Hanoch Pasternak, and Shimon Edelman. Neural Networks for Quality Sorting of Agricultural Produce. United States Department of Agriculture, July 1996. http://dx.doi.org/10.32747/1996.7613033.bard.

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The objectives of this project were to develop procedures and models, based on neural networks, for quality sorting of agricultural produce. Two research teams, one in Purdue University and the other in Israel, coordinated their research efforts on different aspects of each objective utilizing both melons and tomatoes as case studies. At Purdue: An expert system was developed to measure variances in human grading. Data were acquired from eight sensors: vision, two firmness sensors (destructive and nondestructive), chlorophyll from fluorescence, color sensor, electronic sniffer for odor detection, refractometer and a scale (mass). Data were analyzed and provided input for five classification models. Chlorophyll from fluorescence was found to give the best estimation for ripeness stage while the combination of machine vision and firmness from impact performed best for quality sorting. A new algorithm was developed to estimate and minimize training size for supervised classification. A new criteria was established to choose a training set such that a recurrent auto-associative memory neural network is stabilized. Moreover, this method provides for rapid and accurate updating of the classifier over growing seasons, production environments and cultivars. Different classification approaches (parametric and non-parametric) for grading were examined. Statistical methods were found to be as accurate as neural networks in grading. Classification models by voting did not enhance the classification significantly. A hybrid model that incorporated heuristic rules and either a numerical classifier or neural network was found to be superior in classification accuracy with half the required processing of solely the numerical classifier or neural network. In Israel: A multi-sensing approach utilizing non-destructive sensors was developed. Shape, color, stem identification, surface defects and bruises were measured using a color image processing system. Flavor parameters (sugar, acidity, volatiles) and ripeness were measured using a near-infrared system and an electronic sniffer. Mechanical properties were measured using three sensors: drop impact, resonance frequency and cyclic deformation. Classification algorithms for quality sorting of fruit based on multi-sensory data were developed and implemented. The algorithms included a dynamic artificial neural network, a back propagation neural network and multiple linear regression. Results indicated that classification based on multiple sensors may be applied in real-time sorting and can improve overall classification. Advanced image processing algorithms were developed for shape determination, bruise and stem identification and general color and color homogeneity. An unsupervised method was developed to extract necessary vision features. The primary advantage of the algorithms developed is their ability to learn to determine the visual quality of almost any fruit or vegetable with no need for specific modification and no a-priori knowledge. Moreover, since there is no assumption as to the type of blemish to be characterized, the algorithm is capable of distinguishing between stems and bruises. This enables sorting of fruit without knowing the fruits' orientation. A new algorithm for on-line clustering of data was developed. The algorithm's adaptability is designed to overcome some of the difficulties encountered when incrementally clustering sparse data and preserves information even with memory constraints. Large quantities of data (many images) of high dimensionality (due to multiple sensors) and new information arriving incrementally (a function of the temporal dynamics of any natural process) can now be processed. Furhermore, since the learning is done on-line, it can be implemented in real-time. The methodology developed was tested to determine external quality of tomatoes based on visual information. An improved model for color sorting which is stable and does not require recalibration for each season was developed for color determination. Excellent classification results were obtained for both color and firmness classification. Results indicted that maturity classification can be obtained using a drop-impact and a vision sensor in order to predict the storability and marketing of harvested fruits. In conclusion: We have been able to define quantitatively the critical parameters in the quality sorting and grading of both fresh market cantaloupes and tomatoes. We have been able to accomplish this using nondestructive measurements and in a manner consistent with expert human grading and in accordance with market acceptance. This research constructed and used large databases of both commodities, for comparative evaluation and optimization of expert system, statistical and/or neural network models. The models developed in this research were successfully tested, and should be applicable to a wide range of other fruits and vegetables. These findings are valuable for the development of on-line grading and sorting of agricultural produce through the incorporation of multiple measurement inputs that rapidly define quality in an automated manner, and in a manner consistent with the human graders and inspectors.
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Lavrentieva, Olena O., Ihor O. Arkhypov, Olexander I. Kuchma, and Aleksandr D. Uchitel. Use of simulators together with virtual and augmented reality in the system of welders’ vocational training: past, present, and future. [б. в.], February 2020. http://dx.doi.org/10.31812/123456789/3748.

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The article discusses the theory and methods of simulation training, its significance in the context of training specialists for areas where the lack of primary qualification is critical. The most widespread hardware and software solutions for the organization welders' simulation training that use VR- and AR- technologies have been analyzed. A review of the technological infrastructure and software tools for the virtual teaching-and-production laboratory of electric welding has been made on the example of the achievements of Fronius, MIMBUS, Seabery. The features of creating a virtual simulation of the welding process using modern equipment based on studies of the behavioral reactions of the welder have been shown. It is found the simulators allow not only training, but also one can build neuro-fuzzy logic and design automated and robotized welding systems. The functioning peculiarities of welding's simulators with AR have been revealed. It is shown they make it possible to ensure the forming basic qualities of a future specialist, such as concentration, accuracy and agility. The psychological and technical aspects of the coaching programs for the training and retraining of qualified welders have been illustrated. The conclusions about the significant advantages of VR- and AR-technologies in comparison with traditional ones have been made. Possible directions of the development of simulation training for welders have been revealed. Among them the AR-technologies have been presented as such that gaining wide popularity as allow to realize the idea of mass training in basic professional skills.
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Cheng, Peng, James V. Krogmeier, Mark R. Bell, Joshua Li, and Guangwei Yang. Detection and Classification of Concrete Patches by Integrating GPR and Surface Imaging. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317320.

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This research considers the detection, location, and classification of patches in concrete and asphalt-on-concrete pavements using data taken from ground penetrating radar (GPR) and the WayLink 3D Imaging System. In particular, the project seeks to develop a patching table for “inverted-T” patches. A number of deep neural net methods were investigated for patch detection from 3D elevation and image observation, but the success was inconclusive, partly because of a dearth of training data. Later, a method based on thresholding IRI values computed on a 12-foot window was used to localize pavement distress, particularly as seen by patch settling. This method was far more promising. In addition, algorithms were developed for segmentation of the GPR data and for classification of the ambient pavement and the locations and types of patches found in it. The results so far are promising but far from perfect, with a relatively high rate of false alarms. The two project parts were combined to produce a fused patching table. Several hundred miles of data was captured with the Waylink System to compare with a much more limited GPR dataset. The primary dataset was captured on I-74. A software application for MATLAB has been written to aid in automation of patch table creation.
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Cheng, Peng, James V. Krogmeier, Mark R. Bell, Joshua Li, and Guangwei Yang. Detection and Classification of Concrete Patches by Integrating GPR and Surface Imaging. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317320.

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This research considers the detection, location, and classification of patches in concrete and asphalt-on-concrete pavements using data taken from ground penetrating radar (GPR) and the WayLink 3D Imaging System. In particular, the project seeks to develop a patching table for “inverted-T” patches. A number of deep neural net methods were investigated for patch detection from 3D elevation and image observation, but the success was inconclusive, partly because of a dearth of training data. Later, a method based on thresholding IRI values computed on a 12-foot window was used to localize pavement distress, particularly as seen by patch settling. This method was far more promising. In addition, algorithms were developed for segmentation of the GPR data and for classification of the ambient pavement and the locations and types of patches found in it. The results so far are promising but far from perfect, with a relatively high rate of false alarms. The two project parts were combined to produce a fused patching table. Several hundred miles of data was captured with the Waylink System to compare with a much more limited GPR dataset. The primary dataset was captured on I-74. A software application for MATLAB has been written to aid in automation of patch table creation.
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Warrick, Arthur W., Gideon Oron, Mary M. Poulton, Rony Wallach, and Alex Furman. Multi-Dimensional Infiltration and Distribution of Water of Different Qualities and Solutes Related Through Artificial Neural Networks. United States Department of Agriculture, January 2009. http://dx.doi.org/10.32747/2009.7695865.bard.

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The project exploits the use of Artificial Neural Networks (ANN) to describe infiltration, water, and solute distribution in the soil during irrigation. It provides a method of simulating water and solute movement in the subsurface which, in principle, is different and has some advantages over the more common approach of numerical modeling of flow and transport equations. The five objectives were (i) Numerically develop a database for the prediction of water and solute distribution for irrigation; (ii) Develop predictive models using ANN; (iii) Develop an experimental (laboratory) database of water distribution with time; within a transparent flow cell by high resolution CCD video camera; (iv) Conduct field studies to provide basic data for developing and testing the ANN; and (v) Investigate the inclusion of water quality [salinity and organic matter (OM)] in an ANN model used for predicting infiltration and subsurface water distribution. A major accomplishment was the successful use of Moment Analysis (MA) to characterize “plumes of water” applied by various types of irrigation (including drip and gravity sources). The general idea is to describe the subsurface water patterns statistically in terms of only a few (often 3) parameters which can then be predicted by the ANN. It was shown that ellipses (in two dimensions) or ellipsoids (in three dimensions) can be depicted about the center of the plume. Any fraction of water added can be related to a ‘‘probability’’ curve relating the size of the ellipse (or ellipsoid) that contains that amount of water. The initial test of an ANN to predict the moments (and hence the water plume) was with numerically generated data for infiltration from surface and subsurface drip line and point sources in three contrasting soils. The underlying dataset consisted of 1,684,500 vectors (5 soils×5 discharge rates×3 initial conditions×1,123 nodes×20 print times) where each vector had eleven elements consisting of initial water content, hydraulic properties of the soil, flow rate, time and space coordinates. The output is an estimate of subsurface water distribution for essentially any soil property, initial condition or flow rate from a drip source. Following the formal development of the ANN, we have prepared a “user-friendly” version in a spreadsheet environment (in “Excel”). The input data are selected from appropriate values and the output is instantaneous resulting in a picture of the resulting water plume. The MA has also proven valuable, on its own merit, in the description of the flow in soil under laboratory conditions for both wettable and repellant soils. This includes non-Darcian flow examples and redistribution and well as infiltration. Field experiments were conducted in different agricultural fields and various water qualities in Israel. The obtained results will be the basis for the further ANN models development. Regions of high repellence were identified primarily under the canopy of various orchard crops, including citrus and persimmons. Also, increasing OM in the applied water lead to greater repellency. Major scientific implications are that the ANN offers an alternative to conventional flow and transport modeling and that MA is a powerful technique for describing the subsurface water distributions for normal (wettable) and repellant soil. Implications of the field measurements point to the special role of OM in affecting wettability, both from the irrigation water and from soil accumulation below canopies. Implications for agriculture are that a modified approach for drip system design should be adopted for open area crops and orchards, and taking into account the OM components both in the soil and in the applied waters.
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Altstein, Miriam, and Ronald Nachman. Rationally designed insect neuropeptide agonists and antagonists: application for the characterization of the pyrokinin/Pban mechanisms of action in insects. United States Department of Agriculture, October 2006. http://dx.doi.org/10.32747/2006.7587235.bard.

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The general objective of this BARD project focused on rationally designed insect neuropeptide (NP) agonists and antagonists, their application for the characterization of the mechanisms of action of the pyrokinin/PBAN (PK-PBAN) family and the development of biostable, bioavailable versions that can provide the basis for development of novel, environmentally-friendly pest insect control agents. The specific objectives of the study, as originally proposed, were to: (i) Test stimulatory potencies of rationally designed backbone cyclic (BBC) peptides on pheromonotropic, melanotropic, myotropic and pupariation activities; (ii) Test the inhibitory potencies of the BBC compounds on the above activities evoked either by synthetic peptides (PBAN, LPK, myotropin and pheromonotropin) or by the natural endogenous mechanism; (iii) Determine the bioavailability of the most potent BBC compounds that will be found in (ii); (iv) Design, synthesize and examine novel PK/PBAN analogs with enhanced bioavailability and receptor binding; (v) Design and synthesize ‘magic bullet’ analogs and examine their ability to selectively kill cells expressing the PK/PBAN receptor. To achieve these goals the agonistic and antagonistic activities/properties of rationally designed linear and BBC neuropeptide (NP) were thoroughly studied and the information obtained was further used for the design and synthesis of improved compounds toward the design of an insecticide prototype. The study revealed important information on the structure activity relationship (SAR) of agonistic/antagonistic peptides, including definitive identification of the orientation of the Pro residue as trans for agonist activity in 4 PK/PBANbioassays (pheromonotropic, pupariation, melanotropic, & hindgut contractile) and a PK-related CAP₂b bioassay (diuretic); indications that led to the identification of a novel scaffold to develop biostbiostable, bioavailable peptidomimetic PK/PBANagonists/antagonists. The work led to the development of an arsenal of PK/PBAN antagonists with a variety of selectivity profiles; whether between different PKbioassays, or within the same bioassay between different natural elicitors. Examples include selective and non-selective BBC and novel amphiphilic PK pheromonotropic and melanotropic antagonists some of which are capable of penetrating the moth cuticle in efficacious quantities. One of the latter analog group demonstrated unprecedented versatility in its ability to antagonize a broad spectrum of pheromonotropic elicitors. A novel, transPro mimetic motif was proposed & used to develop a strong, selective PK agonist of the melanotropic bioassay in moths. The first antagonist (pure) of PK-related CAP₂b diuresis in flies was developed using a cisPro mimetic motif; an indication that while a transPro orientation is associated with receptor agonism, a cisPro orientation is linked with an antagonist interaction. A novel, biostablePK analog, incorporating β-amino acids at key peptidase-susceptible sites, exhibited in vivo pheromonotropic activity that by far exceeded that of PBAN when applied topically. Direct analysis of neural tissue by state-of-the-art MALDI-TOF/TOF mass spectrometry was used to identify specific PK/PK-related peptides native to eight arthropod pest species [house (M. domestica), stable (S. calcitrans), horn (H. irritans) & flesh (N. bullata) flies; Southern cattle fever tick (B. microplus), European tick (I. ricinus), yellow fever mosquito (A. aegypti), & Southern Green Stink Bug (N. viridula)]; including the unprecedented identification of mass-identical Leu/Ile residues and the first identification of NPs from a tick or the CNS of Hemiptera. Evidence was obtained for the selection of Neb-PK-2 as the primary pupariation factor of the flesh fly (N. bullata) among native PK/PK-related candidates. The peptidomic techniques were also used to map the location of PK/PK-related NP in the nervous system of the model fly D. melanogaster. Knowledge of specific PK sequences can aid in the future design of species specific (or non-specific) NP agonists/antagonists. In addition, the study led to the first cloning of a PK/PBAN receptor from insect larvae (S. littoralis), providing the basis for SAR analysis for the future design of 2ⁿᵈgeneration selective and/or nonselective agonists/antagonists. Development of a microplate ligand binding assay using the PK/PBAN pheromone gland receptor was also carried out. The assay will enable screening, including high throughput, of various libraries (chemical, molecular & natural product) for the discovery of receptor specific agonists/antagonists. In summary, the body of work achieves several key milestones and brings us significantly closer to the development of novel, environmentally friendly pest insect management agents based on insect PK/PBANNPs capable of disrupting critical NP-regulated functions.
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