Journal articles: 'Intrinsic optical signal imaging'

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Yao, Xin-Cheng. "Intrinsic optical signal imaging of retinal activation." Japanese Journal of Ophthalmology 53, no. 4 (July 2009): 327–33. http://dx.doi.org/10.1007/s10384-009-0685-4.

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Das, Aniruddha. "Task-related Responses in Intrinsic-Signal Optical Imaging." Journal of Vision 15, no. 12 (September 1, 2015): 1415. http://dx.doi.org/10.1167/15.12.1415.

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Heimel, J. Alexander, Robin J. Hartman, Josephine M. Hermans, and Christiaan N. Levelt. "Screening mouse vision with intrinsic signal optical imaging." European Journal of Neuroscience 25, no. 3 (February 16, 2007): 795–804. http://dx.doi.org/10.1111/j.1460-9568.2007.05333.x.

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Ribot, Jérôme, Shigeru Tanaka, Hirokazu Tanaka, and Ayako Ajima. "Online analysis method for intrinsic signal optical imaging." Journal of Neuroscience Methods 153, no. 1 (May 2006): 8–20. http://dx.doi.org/10.1016/j.jneumeth.2005.09.016.

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Ba, Alyssa M., Michael Guiou, Nader Pouratian, Arpitha Muthialu, David E. Rex, Andrew F. Cannestra, James W. Y. Chen, and Arthur W. Toga. "Multiwavelength Optical Intrinsic Signal Imaging of Cortical Spreading Depression." Journal of Neurophysiology 88, no. 5 (November 1, 2002): 2726–35. http://dx.doi.org/10.1152/jn.00729.2001.

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Cortical spreading depression (CSD) is an important disease model for migraine and cerebral ischemia. In this study, we exploit the high temporal and spatial resolution of optical imaging to characterize perfusion-dependent and -independent changes in response to CSD and to investigate the etiology of reflectance changes during CSD. In this experiment, we characterized the optical response to CSD at wavelengths that emphasize perfusion-related changes (610 and 550 nm), and we compared these results with 850 nm and blood volume data. Blood volume changes during CSD were recorded using an intravascular fluorescent dye, Texas Red dextran. We observed triphasic optical signals at 850 and 550 nm characterized by spreading waves of increased, decreased, then increased reflectance (Fig. 1 ) which expanded at a rate of approximately 3–5 mm/min. The signal at 610 nm had a similar initial phase, but the phase 2 response was slightly more complex, with a parenchymal decrease in reflectance but a vascular increase in reflectance. Reflectance values decreased in phase three. Blood volume signals were delayed relative to the optical intrinsic signals and corresponded temporally to phases 2 and 3. This is the first study to characterize optical imaging of intrinsic signal responses to CSD, in vivo, at multiple wavelengths. The data presented here suggest that changes in light scattering precede perfusion responses, the blood volume increase (phase 2) is accompanied by a reduction in deoxyhemoglobin, and the blood volume decrease (phase 3) is accompanied by an increase in deoxyhemoglobin. Previous studies have suggested the oligemia of spreading depression was a result of decreased metabolic demand. This study suggests that during the oligemic period there is a greater reduction in oxygen delivery than in demand.

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Chen, J. W. Y., A. M. O'Farrell, and A. W. Toga. "Optical intrinsic signal imaging in a rodent seizure model." Neurology 55, no. 2 (July 25, 2000): 312–15. http://dx.doi.org/10.1212/wnl.55.2.312.

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Yao, Xincheng, and Benquan Wang. "Intrinsic optical signal imaging of retinal physiology: a review." Journal of Biomedical Optics 20, no. 9 (September 25, 2015): 090901. http://dx.doi.org/10.1117/1.jbo.20.9.090901.

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Guevara, E., M. Miranda-Morales, K. Hernández-Vidales, M. Atzori, and F. J. González. "Low-cost embedded system for optical imaging of intrinsic signals." Revista Mexicana de Física 65, no. 6 Nov-Dec (October 31, 2019): 651. http://dx.doi.org/10.31349/revmexfis.65.651.

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This paper describes the proof-of-concept evaluation of a low-cost imaging system for obtaining functional connectivity maps of in vivo murine models. This non-contact system is based on the Raspberry Pi 3 and its V2 camera and offers a method for obtaining resting-state images of brain activity without the use of extrinsic contrast agents. The system was fully characterized in terms of dark signal, linearity, sensor noise resolution and spatial frequency response. One mouse was observed in vivo and functional connectivity maps were obtained by combining resting-state analysis and optical intrinsic signals imaging. Intra-mouse variations in functional connectivity remain consistent across multiple imaging sessions. In principle, inexpensive optical imaging of intrinsic signals allows the study of the mechanisms underlying human brain disorders in well-controlled murine models.

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YAO, XIN-CHENG, LEI LIU, and YANG-GUO LI. "INTRINSIC OPTICAL SIGNAL IMAGING OF RETINAL ACTIVITY IN FROG EYE." Journal of Innovative Optical Health Sciences 02, no. 02 (April 2009): 201–8. http://dx.doi.org/10.1142/s1793545809000462.

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Using a near-infrared (NIR) light flood-illumination imager equipped with a high-speed (120 Hz) CCD camera, we demonstrated optical imaging of stimulus-evoked retinal activity in isolated, but intact, frog eye. Both fast and slow transient intrinsic optical signals (IOSs) were observed. Fast optical response occurred immediately after the stimulus onset, could reach peak magnitude within 100 ms, and correlated tightly with ON and OFF edges of the visible light stimulus; while slow optical response lasted a relatively long time (many seconds). High-resolution images revealed both positive (increasing) and negative (decreasing) IOSs, and dynamic optical change at individual CCD pixels could often exceed 10% of the background light intensity. Our experiment on isolated eye suggests that further development of fast, high (sub-cellular) resolution fundus imager will allow robust detection of fast IOSs in vivo, and thus allow noninvasive, three-dimensional evaluation of retinal neural function.

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Bakin, Jonathan S., Michael C. Kwon, Susan A. Masino, Norman M. Weinberger, and Ron D. Frostig. "Suprathreshold Auditory Cortex Activation Visualized by Intrinsic Signal Optical Imaging." Cerebral Cortex 6, no. 2 (1996): 120–30. http://dx.doi.org/10.1093/cercor/6.2.120.

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Bahar, Sonya, Minah Suh, Mingrui Zhao, and Theodore H. Schwartz. "Intrinsic optical signal imaging of neocortical seizures: the ???epileptic dip???" NeuroReport 17, no. 5 (April 2006): 499–503. http://dx.doi.org/10.1097/01.wnr.0000209010.78599.f5.

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Frostig, Ron D., Susan A. Masino, Mike C. Kwon, and Cynthia H. Chen. "Using light to probe the brain: Intrinsic signal optical imaging." International Journal of Imaging Systems and Technology 6, no. 2-3 (1995): 216–24. http://dx.doi.org/10.1002/ima.1850060212.

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Li, Yi-Chao, Wan-Xing Cui, Xu-Jing Wang, Franklin Amthor, Rong-Wen Lu, Anthony Thompson, and Xin-Cheng Yao. "Intrinsic optical signal imaging of glucose-stimulated insulin secreting β-cells." Optics Express 19, no. 1 (December 21, 2010): 99. http://dx.doi.org/10.1364/oe.19.000099.

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O'Farrell, A. M., D. E. Rex, A. Muthialu, G. K. Wong, N. Pouratian, J. W. Y. Chen, A. F. Cannestra, and A. W. Toga. "Blood volume and optical intrinsic signal imaging of cortical spreading depression." NeuroImage 11, no. 5 (May 2000): S770. http://dx.doi.org/10.1016/s1053-8119(00)91699-9.

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Kohn, A., C. Metz, M. Quibrera, M. A. Tommerdahl, and B. L. Whitsel. "Functional neocortical microcircuitry demonstrated with intrinsic signal optical imaging in vitro." Neuroscience 95, no. 1 (November 1999): 51–62. http://dx.doi.org/10.1016/s0306-4522(99)00385-1.

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Chen-Bee, Cynthia H., Michael C. Kwon, Susan A. Masino, and Ron D. Frostig. "Areal extent quantification of functional representations using intrinsic signal optical imaging." Journal of Neuroscience Methods 68, no. 1 (September 1996): 27–37. http://dx.doi.org/10.1016/0165-0270(96)00056-8.

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Pouratian, Nader, Andrew F. Cannestra, Neil A. Martin, and Arthur W. Toga. "Intraoperative optical intrinsic signal imaging: a clinical tool for functional brain mapping." Neurosurgical Focus 13, no. 4 (October 2002): 1–9. http://dx.doi.org/10.3171/foc.2002.13.4.2.

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Optical imaging of intrinsic signals (OIS) is a well-established neuroimaging modality by which functional cortical activity is mapped by detecting activity-related changes in cortical light reflectance. Light reflectance changes are detected by a charged-coupled device camera that captures images of the exposed cortex both at rest and during activity. Although to date OIS has only been used for research purposes, intraoperative OIS (iOIS) holds promise as a clinical mapping tool. In general, iOIS demonstrates good spatial correlation with electrocortical stimulation mapping (ECSM) and other electrophysiological modalities. Additionally, iOIS offers high spatial resolution (in microns), does not make contact with the surface of the brain, and introduces no potentially harmful compounds. Moreover, mapping is relatively rapid. The authors review the potential contribution of iOIS to the intraoperative environment. Specifically, they review iOIS methodology, discuss signal origin, compare OIS with other functional mapping modalities, and explain its potential benefits and limitations. They propose that iOIS may, in the future, be used in conjunction with ECSM to improve the resolution and accuracy of intraoperative mapping, decrease total time of intraoperative mapping, and possibly improve neurological outcomes. Additional studies will be required to quantify the sensitivity and specificity of optical maps relative to ECSM before it can be implemented clinically.

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Cannestra, Andrew F., Nader Pouratian, Marc H. Shomer, and Arthur W. Toga. "Refractory Periods Observed by Intrinsic Signal and Fluorescent Dye Imaging." Journal of Neurophysiology 80, no. 3 (September 1, 1998): 1522–32. http://dx.doi.org/10.1152/jn.1998.80.3.1522.

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Cannestra, Andrew F., Nader Pouratian, Marc H. Shomer, and Arthur W. Toga. Refractory periods observed by intrinsic signal and fluorescent dye imaging. J. Neurophysiol. 80: 1522–1532, 1998. All perfusion-based imaging modalities depend on the relationship between neuronal and vascular activity. However, the relationship between stimulus and response was never fully characterized. With the use of optical imaging (intrinsic signals and intravascular fluorescent dyes) during repetitive stimulation paradigms, we observed reduced responses with temporally close stimuli. Cortical evoked potentials, however, did not produce the same reduced responsiveness. We therefore termed these intervals of reduced responsiveness “refractory periods.” During these refractory periods an ability to respond was retained, but at a near 60% reduction in the initial magnitude. Although increasing the initial stimulus duration lengthened the observed refractory periods, significantly novel or temporally spaced stimuli overcame them. We observed this phenomenon in both rodent and human subjects in somatosensory and auditory cortices. These results have significant implications for understanding the capacities, mechanisms, and distributions of neurovascular coupling and thereby possess relevance to all perfusion-dependent functional imaging techniques.

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Zhang, Qiu-Xiang, Youwen Zhang, Rong-Wen Lu, Yi-Chao Li, Steven J. Pittler, Timothy W. Kraft, and Xin-Cheng Yao. "Comparative intrinsic optical signal imaging of wild-type and mutant mouse retinas." Optics Express 20, no. 7 (March 20, 2012): 7646. http://dx.doi.org/10.1364/oe.20.007646.

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Guiou, M., A. M. O'Farrell, S. Sheth, N. Pouratian, M. Nemoto, and A. W. Toga. "EEG and multi-wavelength optical intrinsic signal imaging of cortical spreading depression." NeuroImage 13, no. 6 (June 2001): 979. http://dx.doi.org/10.1016/s1053-8119(01)92317-1.

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Chen-Bee, Cynthia H., Teodora Agoncillo, Christopher C. Lay, and Ron D. Frostig. "Intrinsic signal optical imaging of brain function using short stimulus delivery intervals." Journal of Neuroscience Methods 187, no. 2 (March 2010): 171–82. http://dx.doi.org/10.1016/j.jneumeth.2010.01.009.

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Gochin, P. M., P. Bedenbaugh, J. J. Gelfand, C. G. Gross, and G. L. Gerstein. "Intrinsic signal optical imaging in the forepaw area of rat somatosensory cortex." Proceedings of the National Academy of Sciences 89, no. 17 (September 1, 1992): 8381–83. http://dx.doi.org/10.1073/pnas.89.17.8381.

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Provenzano, Paolo P., Kevin W. Eliceiri, Long Yan, Aude Ada-Nguema, Matthew W. Conklin, David R. Inman, and Patricia J. Keely. "Nonlinear Optical Imaging of Cellular Processes in Breast Cancer." Microscopy and Microanalysis 14, no. 6 (November 6, 2008): 532–48. http://dx.doi.org/10.1017/s1431927608080884.

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AbstractNonlinear optical imaging techniques such as multiphoton and second harmonic generation (SHG) microscopy used in conjunction with novel signal analysis techniques such as spectroscopic and fluorescence excited state lifetime detection have begun to be used widely for biological studies. This is largely due to their promise to noninvasively monitor the intracellular processes of a cell together with the cell's interaction with its microenvironment. Compared to other optical methods these modalities provide superior depth penetration and viability and have the additional advantage in that they are compatible technologies that can be applied simultaneously. Therefore, application of these nonlinear optical approaches to the study of breast cancer holds particular promise as these techniques can be used to image exogeneous fluorophores such as green fluorescent protein as well as intrinsic signals such as SHG from collagen and endogenous fluorescence from nicotinamide adenine dinucleotide or flavin adenine dinucleotide. In this article the application of multiphoton excitation, SHG, and fluorescence lifetime imaging microscopy to relevant issues regarding the tumor-stromal interaction, cellular metabolism, and cell signaling in breast cancer is described. Furthermore, the ability to record and monitor the intrinsic fluorescence and SHG signals provides a unique tool for researchers to understand key events in cancer progression in its natural context.

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Reinert, Kenneth C., Robert L. Dunbar, Wangcai Gao, Gang Chen, and Timothy J. Ebner. "Flavoprotein Autofluorescence Imaging of Neuronal Activation in the Cerebellar Cortex In Vivo." Journal of Neurophysiology 92, no. 1 (July 2004): 199–211. http://dx.doi.org/10.1152/jn.01275.2003.

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Autofluorescence has been used as an indirect measure of neuronal activity in isolated cell cultures and brain slices, but only to a limited extent in vivo. Intrinsic fluorescence signals reflect the coupling between neuronal activity and mitochondrial metabolism, and are caused by the oxidation/reduction of flavoproteins or nicotinamide adenine dinucleotide (NADH). The present study evaluated the existence and properties of these autofluorescence signals in the cerebellar cortex of the ketamine/xylazine anesthetized mouse in vivo. Surface stimulation of the unstained cerebellar cortex evoked a narrow, transverse beam of optical activity consisting of a large amplitude, short latency increase in fluorescence followed by a longer duration decrease. The optimal wavelengths for this autofluorescence signal were 420–490 nm for excitation and 515–570 nm for emission, consistent with a flavoprotein origin. The amplitude of the optical signal was linearly related to stimulation amplitude and frequency, and its duration was linearly related to the duration of stimulation. Blocking synaptic transmission demonstrated that a majority of the autofluorescence signal is attributed to activating the postsynaptic targets of the parallel fibers. Hypothesized to be the result of oxidation and subsequent reduction of flavoproteins, blocking mitochondrial respiration with sodium cyanide or inactivation of flavoproteins with diphenyleneiodonium substantially reduced the optical signal. This reduction in the autofluorescence signal was accomplished without altering the presynaptic and postsynaptic components of the electrophysiological response. Results from reflectance imaging and blocking nitric oxide synthase demonstrated that the epifluorescence signal is not the result of changes in hemoglobin oxygenation or blood flow. This flavoprotein autofluorescence signal thus provides a powerful tool to monitor neuronal activity in vivo and its relationship to mitochondrial metabolism.

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Blood, Anne J., Sanjiv M. Narayan, and Arthur W. Toga. "Stimulus Parameters Influence Characteristics of Optical Intrinsic Signal Responses in Somatosensory Cortex." Journal of Cerebral Blood Flow & Metabolism 15, no. 6 (November 1995): 1109–20. http://dx.doi.org/10.1038/jcbfm.1995.138.

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Optical imaging of intrinsic signals was performed in the barrel cortex of the rat during whisker deflections of varying frequencies (1 to 20 Hz) and durations (0.1 to 5 s). A dose–response relationship was shown between these stimuli and the characteristics of the optically recorded intrinsic signal response. At constant frequencies, longer stimulus durations increased response magnitude, as defined by mean pixel value in statistically determined regions of interest. At constant durations, higher stimulus frequencies increased response magnitude. Response magnitude was also increased by greater numbers of deflections. When stimulus number was constant, there were no differences in response magnitude, regardless of stimulus frequency and duration. Spatial extent of responses, as defined by number of pixels in regions of interest, did not differ between stimulus frequencies, durations, or numbers. Comparison of the time to reach peak intrinsic signal response after stimulus onset (“time-to-peak”) suggested that higher frequencies were associated with faster time-to-peak. Registration of intrinsic signal responses with cytochrome oxidase-stained whisker barrels demonstrated that responses were located over the barrel corresponding to the stimulated whisker. In summary, we have shown that the absolute number of stimuli delivered to the system is, at least for short stimulus periods (≤5 s), a determining factor for the magnitude of these responses, whereas stimulus frequency appears to influence time-to-peak response.

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Tommerdahl, Mark, Oleg Favorov, and Barry L. Whitsel. "Optical imaging of intrinsic signals in somatosensory cortex." Behavioural Brain Research 135, no. 1-2 (September 2002): 83–91. http://dx.doi.org/10.1016/s0166-4328(02)00159-6.

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Yao, Xincheng, and Tae-Hoon Kim. "Fast intrinsic optical signal correlates with activation phase of phototransduction in retinal photoreceptors." Experimental Biology and Medicine 245, no. 13 (June 19, 2020): 1087–95. http://dx.doi.org/10.1177/1535370220935406.

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Quantitative assessment of physiological condition of retinal photoreceptors is desirable for better detection and treatment evaluation of eye diseases that can cause photoreceptor dysfunctions. Functional intrinsic optical signal (IOS) imaging, also termed as optoretinography (ORG) or optophysiology, has been proposed as a high-resolution method for objective assessment of retinal physiology. Fast IOS in retinal photoreceptors shows a time course earlier than that of electroretinography a-wave, promising an objective marker for noninvasive ORG of early phototransduction process in retinal photoreceptors. In this article, recent observations of fast photoreceptor-IOS in animal and human retinas are summarized, and the correlation of fast photoreceptor-IOS to five steps of phototransduction process is discussed. Transient outer segment conformational change, due to inter-disc space shrinkage correlated with activation phase of phototransduction, has been disclosed as a primary source of the fast photoreceptor-IOS. Impact statement As the center of phototransduction, retinal photoreceptors are responsible for capturing and converting photon energy to bioelectric signals for following visual information processing in the retina. This article summarizes experimental observation and discusses biophysical mechanism of fast photoreceptor-intrinsic optical signal (IOS) correlated with early phase of phototransduction. Quantitative imaging of fast photoreceptor-IOS may provide objective optoretinography to advance the study and diagnosis of age-related macular degeneration, retinitis pigmentosa, diabetic retinopathy, and other eye diseases that can cause photoreceptor dysfunctions.

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Lu, Haidong D., Gang Chen, Junjie Cai, and Anna W. Roe. "Intrinsic signal optical imaging of visual brain activity: Tracking of fast cortical dynamics." NeuroImage 148 (March 2017): 160–68. http://dx.doi.org/10.1016/j.neuroimage.2017.01.006.

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Tanigawa, Hisashi, and Anna Wang Roe. "Distribution of attentional modulation in macaque V4 revealed by intrinsic signal optical imaging." Neuroscience Research 68 (January 2010): e102. http://dx.doi.org/10.1016/j.neures.2010.07.213.

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Shou, Tiande. "Probing functions of visual cortex using intrinsic signal optical imaging and other methods." International Congress Series 1269 (August 2004): 6–10. http://dx.doi.org/10.1016/j.ics.2004.05.158.

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Versnel, Huib, Jennifer E. Mossop, Thomas D. Mrsic-Flogel, Bashir Ahmed, and David R. Moore. "Optical Imaging of Intrinsic Signals in Ferret Auditory Cortex: Responses to Narrowband Sound Stimuli." Journal of Neurophysiology 88, no. 3 (September 1, 2002): 1545–58. http://dx.doi.org/10.1152/jn.2002.88.3.1545.

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This paper describes optical imaging of the auditory cortex in the anesthetized ferret, particularly addressing optimization of narrowband stimuli. The types of sound stimuli used were tone-pip trains and sinusoidal frequency and amplitude modulated (SFM and SAM) tones. By employing short illumination wavelengths (546 nm), we have successfully characterized the tonotopic arrangement, in agreement with the well-established electrophysiological tonotopic maps of the ferret auditory primary field (AI). The magnitude of the optical signal increased with sound level, was maximal for a modulation frequency (MF) of 2–4 Hz, and was larger for tone-pip trains and SFM sounds than for SAM sounds. Accordingly, an optimal narrowband stimulus was defined. Thus optical imaging can be used successfully to obtain frequency maps in auditory cortex by an appropriate choice of stimulus parameters. In addition, background noise consisting of 0.1-Hz oscillations could be reduced by introduction of blood pressure enhancing drugs. The optical maps were largely independent of 1) the type of narrowband stimulus, 2) the sound level, and 3) the MF. This stability of the optical maps was not predicted from the electrophysiological literature.

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SUN, XIAOLI, PENGCHENG LI, WEIHUA LUO, BIYING GONG, and QINGMING LUO. "ACCURATELY DETERMINING PROPAGATION VELOCITY OF CORTICAL SPREADING DEPRESSION IN RATS BY OPTICAL INTRINSIC SIGNAL IMAGING." Journal of Innovative Optical Health Sciences 03, no. 02 (April 2010): 103–8. http://dx.doi.org/10.1142/s1793545810000915.

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Cortical spreading depression (CSD) is a wave of neuronal and glial depolarization that propagates across the cortex at a rate of 2–5 mm/min accompanied by reversible electroencephalogram (EEG) suppression, a negative shift of direct current (DC) potential, and change of optical intrinsic signals (OIS). Propagation velocity of CSD is an important parameter used to study this phenomenon. It is commonly determined in an electrophysiological way that measures the time required for a CSD wave to pass along two electrodes. Since the electrophysiology technique fails to reveal the spreading pattern of CSD, velocity calculated in this manner might be inaccurate. In this study, we combined the electrophysiological recording and OIS imaging (OISI) for detecting changes in DC potential and OIS during CSD simultaneously. An optical method based on OISI to determine the CSD velocity, which is measured by generating a series of regions of interest (ROI) perpendicular to the advancing wavefront along propagation direction of CSD at different time points and then dividing by the distance between ROIs over time, is presented. Comparison of the accuracy of the two approaches in determining the CSD velocity is made as well. The average rate of 33 CSDs is 3.52 ± 0.87 mm/min by use of the optical method and 4.36 ± 1.65 mm/min by use of the electrophysiological method. Because of the information about spreading pattern of CSD provided optically, the velocity determined by OISI is of smaller deviation and higher accuracy.

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Teussink, Michel M., Barry Cense, Mark J. J. P. van Grinsven, B. Jeroen Klevering, Carel B. Hoyng, and Thomas Theelen. "Impact of motion-associated noise on intrinsic optical signal imaging in humans with optical coherence tomography." Biomedical Optics Express 6, no. 5 (April 9, 2015): 1632. http://dx.doi.org/10.1364/boe.6.001632.

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Harrison, Robert V., Noam Harel, Akinobu Kakigi, Eyal Raveh, and Richard J. Mount. "Optical Imaging of Intrinsic Signals in Chinchilla Auditory Cortex." Audiology and Neurotology 3, no. 2-3 (1998): 214–23. http://dx.doi.org/10.1159/000013791.

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MacVicar, Brian A. "REVIEW ■ : Mapping Neuronal Activity by Imaging Intrinsic Optical Signals." Neuroscientist 3, no. 6 (November 1997): 381–88. http://dx.doi.org/10.1177/107385849700300611.

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Polley, Daniel B., Cynthia H. Chen-Bee, and Ron D. Frostig. "Varying the Degree of Single-Whisker Stimulation Differentially Affects Phases of Intrinsic Signals in Rat Barrel Cortex." Journal of Neurophysiology 81, no. 2 (February 1, 1999): 692–701. http://dx.doi.org/10.1152/jn.1999.81.2.692.

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Varying the degree of single-whisker stimulation differentially affects phases of intrinsic signals in rat barrel cortex. . Neurophysiol. 81: 692–701, 1999. Using intrinsic signal optical imaging (ISI), we have shown previously that the point spread of evoked activity in the rat barrel cortex in response to single-whisker stimulation encompasses a surprisingly large area. Given that our typical stimulation consists of five deflections at 5 Hz, the large area of evoked activity might have resulted from repetitive stimulation. Thus in the present study, we use ISI through the thinned skull to determine whether decreasing the degree of single-whisker stimulation decreases the area of the cortical point spread. We additionally outline a protocol to quantify stimulus-related differences in the temporal characteristics of intrinsic signals at a fine spatial scale. In 10 adult rats, whisker C2 was stimulated randomly with either one or five deflections delivered in a rostral-to-caudal fashion. Each deflection consisted of a 0.5-mm displacement of the whisker as measured at the point of contact, 15 mm from the snout. The number of whisker deflections did not affect the area or peak magnitude of the cortical point spread based on the intrinsic signal activity occurring from 0.5 up to 1.5 s poststimulus onset. In contrast, the magnitude and time course of intrinsic signal activity collected after 1.5-s poststimulus onset did reflect the difference in the degree of stimulation. Thus decreasing the degree of stimulation differentially affected the early and late phases of the evoked intrinsic signal response. The implications of the present results are discussed in respect to probable differences in the signal source underlying the early versus later phases of evoked intrinsic signals.

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Chen, Shangbin, Pengcheng Li, Weihua Luo, Hui Gong, Shaoqun Zeng, and Qingming Luo. "Time-varying spreading depression waves in rat cortex revealed by optical intrinsic signal imaging." Neuroscience Letters 396, no. 2 (March 2006): 132–36. http://dx.doi.org/10.1016/j.neulet.2005.11.025.

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Harel, N., R. V. Harrison, S. Sawada, N. Mori, and R. J. Mount. "Optical imaging of intrinsic signal changes to sound frequency and intensity in auditory cortex." NeuroImage 7, no. 4 (May 1998): S371. http://dx.doi.org/10.1016/s1053-8119(18)31204-7.

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Tsytsarev, Vassiliy, Kaushalya Premachandra, Daisuke Takeshita, and Sonya Bahar. "Imaging cortical electrical stimulation in vivo: fast intrinsic optical signal versus voltage-sensitive dyes." Optics Letters 33, no. 9 (April 30, 2008): 1032. http://dx.doi.org/10.1364/ol.33.001032.

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Fan, Reuben H., Mary K. L. Baldwin, Walter J. Jermakowicz, Vivien A. Casagrande, Jon H. Kaas, and Anna W. Roe. "Intrinsic signal optical imaging evidence for dorsal V3 in the prosimian galago (Otolemur garnettii)." Journal of Comparative Neurology 520, no. 18 (October 20, 2012): 4254–74. http://dx.doi.org/10.1002/cne.23154.

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Shirkavand, Afshan, Ezeddin Mohajerani, Shirin Farivar, Leila Ataie-Fashtami, and Mohammad Hossein Ghazimoradi. "Quantitative Autofluorescence Imaging of A375 Human Melanoma Cell Samples: A Pilot Study." Journal of Lasers in Medical Sciences 12 (February 14, 2021): e4-e4. http://dx.doi.org/10.34172/jlms.2021.04.

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Introduction: Skin cancer is one of the most common types of malignancy worldwide. Human skin naturally contains several endogenous fluorophores, as potential sources can emit inherent fluorescence, called intrinsic autofluorescence (AF). The melanin endogenous fluorophore in the basal cell layer of the epidermis seems to have a strong autofluorescence signal among other ones in the skin. This pilot study aimed to investigate the feasibility of the detection of autofluorescence signals in the A375 human melanoma cell line in the cell culture stage using the FluoVision optical imaging system. Methods: The human skin melanoma cell line (A375) donated as a gift from Switzerland (University Hospital Basel) was cultured. For the imaging of the A375 human melanoma cell sample in this pilot study, the FluoVision optical imaging device (Tajhiz Afarinan Noori Parseh Co) was applied. The proposed clustering image processing code was developed based on the K-mean segmentation method, using MATLAB software (version 16). Results: The quantification of color pixels in the color bar along with the intensity score of the autofluorescence signal ranged between 0 and 70 was written in the image processing code execution and a threshold higher than 40%, proportional to the ratio of autofluorescent cells. The percentage of the signal of A375 autofluorescent melanoma cells in the 3 studied cell samples was calculated as 3.11%±0.6. Conclusion: This imaging method has the advantage of no need for fluorophore labels over the existing fluorescence imaging methods, and it can be regarded as one of the important choices of label-free imaging for this A375 melanoma cell line containing the intrinsic endogenous fluorophore in cell studies.

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Santos, Edgar, Fiorella León, Humberto Silos, Renan Sanchez-Porras, C. William Shuttleworth, Andreas Unterberg, and Oliver W. Sakowitz. "Incidence, hemodynamic, and electrical characteristics of spreading depolarization in a swine model are affected by local but not by intravenous application of magnesium." Journal of Cerebral Blood Flow & Metabolism 36, no. 12 (October 1, 2016): 2051–57. http://dx.doi.org/10.1177/0271678x16671317.

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The aim was to characterize the effects of magnesium sulfate, using i.v. bolus and local administration, using intrinsic signal imaging, and on electrocorticographic activity during the induction and propagation of spreading depolarizations in the gyrencephalic porcine brain. Local application of magnesium sulfate led to a complete inhibition of spreading depolarizations. One hour after washing out the topical magnesium sulfate, re-incidence of the spreading depolarizations was observed in 50% of the hemispheres. Those spreading depolarizations showed attenuation in hemodynamic characteristics and speed in intrinsic optical signal imaging. The electrical amplitude decreased through electrocorticographic activity. Intravenous magnesium therapy showed no significant effects on spreading depolarization incidence and characteristics.

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Tommerdahl, M., K. A. Delemos, C. J. Vierck, O. V. Favorov, and B. L. Whitsel. "Anterior parietal cortical response to tactile and skin-heating stimuli applied to the same skin site." Journal of Neurophysiology 75, no. 6 (June 1, 1996): 2662–70. http://dx.doi.org/10.1152/jn.1996.75.6.2662.

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1. The response of anterior parietal cortex to skin stimuli was evaluated with optical intrinsic signal imaging and extracellular microelectrode recording methods in anesthetized squirrel monkeys. 2. Nonnoxious mechanical stimulation (vibrotactile or skin tapping) of the contralateral radial interdigital pad was accompanied by a decrease in reflectance (at 833 nm) in sectors of cytoarchitectonic areas 3b and 1. This intrinsic signal was in register with regions shown by previous receptive field mapping studies to receive low-threshold mechanoreceptor input from the radial interdigital pad. 3. A skin-heating stimulus applied to the contralateral radial interdigital pad with a stationary probe/thermode evoked no discernable intrinsic signal in areas 3b and 1, but evoked a signal within a circumscribed part of area 3a. The region of area 3a responsive to skin heating with the stationary probe/thermode was adjacent to the areas 3b and 1 regions that developed an intrinsic signal in response to vibrotactile stimulation of the same skin site. Skin heating with a stationary probe/thermode also evoked intrinsic signal in regions of areas 4 and 2 neighboring the area 3b/1 regions activated by vibrotactile stimulation of the contralateral radial interdigital pad. 4. The intrinsic signal evoked in area 3a by a series of heating stimuli to the contralateral radial interdigital pad (applied with a stationary probe/thermode) increased progressively in magnitude with repeated stimulation (exhibited slow temporal summation) and remained above prestimulus levels for a prolonged period after termination of repetitive stimulation. 5. Brief mechanical stimuli (,taps”) applied to the contralateral radial interdigital pad with a probe/thermode maintained either at 37 degrees C or at 52 degrees C were accompanied by the development of an intrinsic signal in both area 3a and areas 3b/1. For the 52 degrees C stimulus, the area 3a intrinsic signal was larger and the intrinsic signal in areas 3b/1 smaller than the corresponding signals evoked by the 37 degrees C stimulus. 6. Spike discharge activity was recorded from area 3a neurons during a repetitive heating stimulus applied with a stationary probe/ thermode to the contralateral radial interdigital pad. Like the area 3a intrinsic signal elicited by repetitive heating of the same skin site, the area 3a neuron spike discharge activity also exhibited slow temporal summation and poststimulus response persistence. 7. The experimental findings suggest 1) a leading role for area 3a in the anterior parietal cortical processing of skin-heating stimuli, and 2) the presence of inhibitory interactions between the anterior parietal responses to painful and vibrotactile stimuli consistent with those demonstrated in recent cortical imaging and psychophysical studies of human subjects.

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Kohno, Satoru, Nobukatsu Sawamoto, Shin-ichi Urayama, Toshihiko Aso, Kenji Aso, Akitoshi Seiyama, Hidenao Fukuyama, and Denis Le Bihan. "Water-Diffusion Slowdown in the Human Visual Cortex on Visual Stimulation Precedes Vascular Responses." Journal of Cerebral Blood Flow & Metabolism 29, no. 6 (April 22, 2009): 1197–207. http://dx.doi.org/10.1038/jcbfm.2009.45.

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We used magnetic resonance imaging (MRI) to investigate the temporal dynamics of changes in water diffusion and blood oxygenation level-dependent (BOLD) responses in the brain cortex of eight subjects undergoing visual stimulation, and compared them with changes of the vascular hemoglobin content (oxygenated, deoxygenated, and total hemoglobin) acquired simultaneously from intrinsic optical recordings (near infrared spectroscopy). The group average rise time for the diffusion MRI signal was statistically significantly shorter than those of the BOLD signal and total hemoglobin content optical signal, which is assumed to be the fastest observable vascular signal. In addition, the group average decay time for the diffusion MRI also was shortest. The overall time courses of the BOLD and optical signals were strongly correlated, but the covariance was weaker with the diffusion MRI response. These results suggest that the observed decrease in water diffusion reflects early events that precede the vascular responses, which could originate from changes in the extravascular tissue.

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CANG, JIANHUA, VALERY A. KALATSKY, SIEGRID LÖWEL, and MICHAEL P. STRYKER. "Optical imaging of the intrinsic signal as a measure of cortical plasticity in the mouse." Visual Neuroscience 22, no. 5 (September 2005): 685–91. http://dx.doi.org/10.1017/s0952523805225178.

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The responses of cells in the visual cortex to stimulation of the two eyes changes dramatically following a period of monocular visual deprivation (MD) during a critical period in early life. This phenomenon, referred to as ocular dominance (OD) plasticity, is a widespread model for understanding cortical plasticity. In this study, we designed stimulus patterns and quantification methods to analyze OD in the mouse visual cortex using optical imaging of intrinsic signals. Using periodically drifting bars restricted to the binocular portion of the visual field, we obtained cortical maps for both contralateral (C) and ipsilateral (I) eyes and computed OD maps as (C − I)/(C + I). We defined the OD index (ODI) for individual animals as the mean of the OD map. The ODI obtained from an imaging session of less than 30 min gives reliable measures of OD for both normal and monocularly deprived mice under Nembutal anesthesia. Surprisingly, urethane anesthesia, which yields excellent topographic maps, did not produce consistent OD findings. Normal Nembutal-anesthetized mice have positive ODI (0.22 ± 0.01), confirming a contralateral bias in the binocular zone. For mice monocularly deprived during the critical period, the ODI of the cortex contralateral to the deprived eye shifted negatively towards the nondeprived, ipsilateral eye (ODI after 2-day MD: 0.12 ± 0.02, 4-day: 0.03 ± 0.03, and 6- to 7-day MD: −0.01 ± 0.04). The ODI shift induced by 4-day MD appeared to be near maximal, consistent with previous findings using single-unit recordings. We have thus established optical imaging of intrinsic signals as a fast and reliable screening method to study OD plasticity in the mouse.

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Sheth, Bhavin R., Christopher I. Moore, and Mriganka Sur. "Temporal Modulation of Spatial Borders in Rat Barrel Cortex." Journal of Neurophysiology 79, no. 1 (January 1, 1998): 464–70. http://dx.doi.org/10.1152/jn.1998.79.1.464.

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Sheth, Bhavin R., Christopher I. Moore, and Mriganka Sur. Temporal modulation of spatial borders in rat barrel cortex. J. Neurophysiol. 79: 464–470, 1998. We examined the effects of varying vibrissa stimulation frequency on intrinsic signal and neuronal responses in rat barrel cortex. Optical imaging of intrinsic signals demonstrated that the region of cortex activated by deflection of a single vibrissa at 1 Hz is more diffuse and more widespread than the territory activated at 5 or 10 Hz. With the use of two different paradigms, constant time of stimulation and constant number of vibrissa deflections, we showed that the optically imaged spread of activity is more discrete at higher stimulation frequencies. We combined optical imaging with multiple electrode recording and confirmed that the neuronal response to individual vibrissa stimulation at the optically imaged center of activity is greater than the response away from the imaged center. Consistent with the imaging data, these recordings also showed no response to a second vibrissa deflection at 5 Hz at a peripheral recording site, though there was a significant response to a second vibrissa deflection at 1 Hz at the same peripheral site. These findings demonstrate that vibrissa stimulation at higher frequencies leads to more focused physiological responses in cortex. Thus the spread of activation in rat barrel cortex is modulated in a dynamic fashion by the frequency of vibrissa stimulation.

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Mironov, Sergey F., Frederick J. Vetter, and Arkady M. Pertsov. "Fluorescence imaging of cardiac propagation: spectral properties and filtering of optical action potentials." American Journal of Physiology-Heart and Circulatory Physiology 291, no. 1 (July 2006): H327—H335. http://dx.doi.org/10.1152/ajpheart.01003.2005.

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Fluorescence imaging using voltage-sensitive dyes is an important tool for studying electrical propagation in the heart. Yet, the low amplitude of the voltage-sensitive component in the fluorescence signal and high acquisition rates dictated by the rapid propagation of the excitation wave front make it difficult to achieve recordings with high signal-to-noise ratios. Although spatially and temporally filtering the acquired signals has become de facto one of the key elements of optical mapping, there is no consensus regarding their use. Here we characterize the spatiotemporal spectra of optically recorded action potentials and determine the distortion produced by conical filters of different sizes. On the basis of these findings, we formulate the criteria for rational selection of filter characteristics. We studied the evolution of the spatial spectra of the propagating wave front after epicardial point stimulation of the isolated, perfused right ventricular free wall of the pig heart stained with di-4-ANEPPS. We found that short-wavelength (<3 mm) spectral components represent primarily noise and surface features of the preparation (coronary vessels, fat, and connective tissue). The time domain of the optical action potential spectrum also lacks high-frequency components (>100 Hz). Both findings are consistent with the reported effect of intrinsic blurring caused by light scattering inside the myocardial wall. The absence of high-frequency spectral components allows the use of aggressive low-pass spatial and temporal filters without affecting the optical action potential morphology. We show examples where the signal-to-noise ratio increased up to 150 with <3% distortion. A generalization of our approach to the rational filter selection in various applications is discussed.

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MacVicar, BA, and D. Hochman. "Imaging of synaptically evoked intrinsic optical signals in hippocampal slices." Journal of Neuroscience 11, no. 5 (May 1, 1991): 1458–69. http://dx.doi.org/10.1523/jneurosci.11-05-01458.1991.

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Kisvarday, Z. F., P. Buzas, and U. T. Eysel. "Calculating Direction Maps from Intrinsic Signals revealed by Optical Imaging." Cerebral Cortex 11, no. 7 (July 1, 2001): 636–47. http://dx.doi.org/10.1093/cercor/11.7.636.

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George, J. S., and X. c. Yao. "Imaging fast intrinsic optical signals for studies of retinal function." Journal of Vision 6, no. 6 (March 18, 2010): 1099. http://dx.doi.org/10.1167/6.6.1099.

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Journal articles on the topic 'Intrinsic optical signal imaging'

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