Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Serotonin, control of breathing.
Дисертації з теми "Serotonin, control of breathing"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Serotonin, control of breathing".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Thomas, Dr Mike. "Dysfunctional breathing and asthma : can breathing exercises improve asthma control?" Thesis, University of Aberdeen, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531907.
Повний текст джерелаАнотація:
The hypothesis underlying this thesis was that abnormal, dysfunctional breathing may occur commonly in people with asthma, and when identified and treated using a breathing training programme supervised by a physiotherapist, will result in improved asthma control. The thesis is based around four original research papers published in peer-reviewed journals. These papers present epidemiological surveys quantifying the extent of symptoms attributable to dysfunctional breathing in adults with asthma in comparison with the non-asthmatic adult population, and randomised controlled trials investigating the effectiveness of a breathing training programme in improving asthma control. Initially, a review of the existing evidence of co-morbidity between asthma and dysfunctional breathing is presented, together with that of effectiveness of breathing training interventions. In subsequent chapters, two epidemiological surveys are presented, showing that symptoms consistent with dysfunctional breathing were more common in the asthmatic than the non-asthmatic adult population. Data from a pilot and a subsequent full randomised controlled trial are then presented. These show that breathing training was associated with improved patient-reported outcomes in comparison with a control intervention of asthma education (chosen to control for the non-specific effects of professional contact and interest on a symptomatic patient). The thesis shows that in a clinical trial situation, many people with asthma can benefit from breathing training.
2
Pearson, S. B. "Studies on the control of breathing." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235877.
Повний текст джерела
3
Brust, Rachael Danielle. "A specialized serotonergic neuron subtype transduces chemosensory signals and regulates breathing." Thesis, Harvard University, 2014. http://dissertations.umi.com/gsas.harvard:11401.
Повний текст джерелаАнотація:
Serotonergic neurons modulate a wide range of behaviors and functions, from mood and aggression to vital autonomic processes like heart rate, respiratory dynamics, and body temperature. We hypothesize that this broad scope reflects the collective actions of many functionally and molecularly distinct subtypes of serotonergic neurons, each with specialized roles in different neural processes. Supporting this idea are examples of heterogeneity among serotonergic neurons with respect to developmental origin, biophysical properties, and molecular expression; yet deciphering the functional and behavioral relevance of these differences has been challenging. In order to better understand serotonergic system organization, we have developed and applied a set of mouse genetic tools to subdivide serotonergic neurons into groups based on molecular criteria, and then to query these subtypes for differences with respect to biophysical properties, hodology, gene expression, and whole animal function. We applied these tools in a stage-wise fashion, from neural system en masse, as reference, and then to specific serotonergic neuron subtypes. From this, we have established that serotonergic neurons play key roles in at least two life-sustaining reflexes - the respiratory chemoreflex (breathing modulation to keep tissue PCO2/pH within physiological limits) and body temperature regulation. We found that chemoreflex modulation, but not body temperature regulation, maps to a specific serotonergic neuron subtype - that subtype with a developmental history of Egr2 gene expression. Further, in brain slice preparations, we found that this subtype is chemosensitive, increasing firing rate in response to conditions of hypercapnic acidosis. Thus, in vivo, Egr2-serotonergic neurons likely transduce chemosensory information into action potential firing to increase respiratory drive and ultimately breathing. Further, we found that Egr2-serotonergic neurons project selectively to respiratory nuclei involved in PCO2/pH sensory signal transduction, but not primary respiratory motor nuclei. This indicates that the serotonergic system has distinct sensory and motor divisions - another unexpected finding. In summary, these results establish a previously unappreciated functional modularity and organization to the serotonergic system, and open up potential for tailored function-specific therapeutic strategies, for example here as relates to disorders of respiratory homeostasis or thermoregulation.
4
Silva, D. D. N. de. "Central control of breathing in animals under anaesthesia." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238393.
Повний текст джерела
5
Andrews, David C. "Breathing control and thermoregulation in the developing lamb." Thesis, Oxford Brookes University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359674.
Повний текст джерела
6
Russell, Matthew. "DIAPHRAGMATIC BREATHING AND ITS EFFECT ON INHIBITORY CONTROL." UKnowledge, 2014. http://uknowledge.uky.edu/psychology_etds/53.
Повний текст джерелаАнотація:
Evidence suggests that slow paced diaphragmatic breathing (DB) can significantly affect prefrontal cortex functions through increasing an individual’s physiological self-regulatory capacity. The current research demonstrates the effects of paced DB on inhibitory control, which is considered to be a reliable measure of behavioral self-regulation. Eighty healthy participants were randomly assigned to one of two conditions (20 males and females each). Participants were instructed on either DB at a pace of six-breaths per minute (BPM) or instructions on environmental awareness and asked to breathe at 12 BPM. Following training, all participants completed a computer-based task designed to examine inhibitory processes. Physiological recordings of heart rate (HR), BPM, and HRV were collected at baseline, during the breathing training, during the cued go/no-go task, and after the cued go/no-go task. The findings demonstrated that the DB condition had significantly lower BPM, HR, and higher HRV (p’s<0.05) during active training than the environmental awareness condition. Furthermore, the DB condition performed significantly better on the measure of inhibition than the environmental awareness condition (p<0.05). The use of DB as a reliable method to increase physiological self-regulatory capacity and improve behavioral self-regulation, measured as inhibitory control, should continue to be explored.
7
Tin, Chung 1980. "Afferents integration and neural adaptive control of breathing." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/67603.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references.
The respiratory regulatory system is one of the most extensively studied homeostatic systems in the body. Despite its deceptively mundane physiological function, the mechanism underlying the robust control of the motor act of breathing in the face of constantly changing internal and external challenges throughout one's life is still poorly understood. Traditionally, control of breathing has been studied with a highly reductionist approach, with specific stimulus-response relationships being taken to reflect distinct feedback/feedforward control laws. It is assumed that the overall respiratory response could be described as the linear sum of all unitary stimulus-response relationships under a Sherringtonian framework. Such a divide-and-conquer approach has proven useful in predicting the independent effects of specific chemical and mechanical inputs. However, it has limited predictive power for the respiratory response in realistic disease states when multiple factors come into play. Instead, vast amounts of evidence have revealed the existence of complex interactions of various afferent-efferent signals in defining the overall respiratory response. This thesis aims to explore the nonlinear interaction of afferents in respiratory control. In a series of computational simulations, it was shown that the respiratory response in humans during muscular exercise under a variety of pulmonary gas exchange defects is consistent with an optimal interaction of mechanical and chemical afferents. This provides a new understanding on the impacts of pulmonary gas exchange on the adaptive control of the exercise respiratory response. Furthermore, from a series of in-vivo neurophysiology experiments in rats, it was discovered that certain respiratory neurons in the dorsolateral pons in the rat brainstem integrate central and peripheral chemoreceptor afferent signals in a hypoadditive manner. Such nonlinear interaction evidences classical (Pavlovian) conditioning of chemoreceptor inputs that modulate the respiratory rhythm and motor output. These findings demonstrate a powerful gain modulation function for control of breathing by the lower brain. The computational and experimental studies in this thesis reveal a form of associative learning important for adaptive control of respiratory regulation, at both behavioral and neuronal levels. Our results shed new light for future experimental and theoretical elucidation of the mechanism of respiratory control from an integrative modeling perspective.
by Chung Tin.
Ph.D.
8
Fiorentini, Lisa. "Nonlinear Adaptive Controller Design For Air-breathing Hypersonic Vehicles." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1274986563.
Повний текст джерела
9
Sigthorsson, David O. "Control-Oriented Modeling and Output Feedback Control of Hypersonic Air-Breathing Vehicles." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1228230786.
Повний текст джерела
10
Calder, Nicole Andrea. "Development of chemical control of breathing in the newborn." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243416.
Повний текст джерела
11
Sudalagunta, Praneeth Reddy. "Control-oriented Modeling of an Air-breathing Hypersonic Vehicle." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/72872.
Повний текст джерелаАнотація:
Design and development of future high speed aircraft require the use of advanced modeling tools early on in the design phase to study and analyze complex aeroelastic, thermoelastic, and aerothermal interactions. This phase, commonly referred to as the conceptual design phase, involves using first principle based analytical models to obtain a practical starting point for the preliminary and detailed design phases. These analytical models are expected to, firstly, capture the effect of complex interactions between various subsystems using basic physics, and secondly, minimize computational costs. The size of a typical air-breathing hypersonic vehicle can vary anywhere between 12 ft, like the NASA X-43A, to 100 ft, like the NASP demonstrator vehicle. On the other hand, the performance expectations can vary anywhere between cruising at Mach 5 @ 85; 000 ft to Mach 10 @ 110; 000 ft. Reduction of computational costs is essential to efficiently sort through such a vast design space, while capturing the various complex interactions between subsystems has shown to improve accuracy of the design estimates. This motivates the need to develop modelling tools using first principle based analytical models with "needed" fidelity, where fidelity refers to the extent of interactions captured. With the advent of multidisciplinary design optimization tools, the need for an integrated modelling and analysis environment for high speed aircraft has increased substantially over the past two decades. The ever growing increase in performance expectations has made the traditional design approach of optimize first, integrate later obsolete. Designing a closed-loop control system for an aircraft might prove to be a difficult task with a geometry that yields an optimal (L/D) ratio, a structure with optimal material properties, and a propulsion system with maximum thrust-weight ratio. With all the subsystems already optimized, there is very little freedom for control designers to achieve their high performance goals. Integrated design methodologies focus on optimizing the overall design, as opposed to individual subsystems. Control-oriented modelling is an approach that involves making appropriate assumptions while modelling various subsystems in order to facilitate the inclusion of control design during the conceptual design phase. Due to their high lift-to-drag ratio and low operational costs, air-breathing hypersonic vehicles have spurred some interest in the field of high speed aircraft design over the last few decades. Modeling aeroelastic effects for such an aircraft is challenging due to its tightly integrated airframe and propulsion system that leads to significant deflections in the thrust vector caused by flexing of the airframe under extreme aerodynamic and thermal loads. These changes in the orientation of the thrust vector in turn introduce low frequency oscillations in the flight path angle, which make control system design a challenging task. Inclusion of such effects in the vehicle dynamics model to develop accurate control laws is an important part of control-oriented modeling. The air-breathing hypersonic vehicle considered here is assumed to be a thin-walled structure, where deformations due to axial, bending, shear, and torsion are modeled using the six independent displacements of a rigid cross section. Free vibration mode shapes are computed accurately using a novel scheme that uses estimates of natural frequency from the Ritz method as initial guesses to solve the governing equations using SUPORE, a two-point boundary value problem solver. A variational approach involving Hamilton's principle of least action is employed to derive the second order nonlinear equations of motion for the flexible aircraft. These nonlinear equations of motion are then linearized about a given cruise condition, modal analysis carried out on the linearized system, and the coupling between various significant modes studied. Further, open-loop stability analysis in time domain is conducted.Ph. D.
12
Watson, Carole Susan. "Central control of fetal breathing movements, hypoxia and ethanol exposure." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ31124.pdf.
Повний текст джерела
13
Wilson, Christine R. (Christine Roberts). "The role of diaphragmatic afferents in the control of breathing." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28960.
Повний текст джерелаАнотація:
This thesis addresses the role of diaphragmatic afferents in the regulation of breathing. The activation of diaphragmatic thin-fiber afferents by bradykinin, a physiological substance produced during muscle contraction, caused a stimulation and a redistribution of inspiratory motor drive, and a decrease in inspiratory time. These afferents are also involved in the regulation of airway smooth muscle tone, since tracheal tension and lung resistance decreased during electrical activation of the phrenic nerve. To mimic in vivo activation of mechanoreceptive afferents, phrenic nerve stimulation was performed during inspiration or expiration. Similar increases in inspiratory motor drive and respiratory timing occurred during inspiratory and expiratory phrenic stimulation. In addition, vagal input potentiated the stimulatory effect of inspiratory phrenic, but not tibial, nerve activation. Prolonged activation of diaphragmatic thin-fiber afferents by ischemia caused inspiratory motor drive to increase and then decrease to baseline values. These findings indicate either a depletion of neurotransmitter substance within afferent pathways, or the development of central inhibition of ventilatory drive. In summary, diaphragmatic thin-fiber afferent activity is an important modulating influence in the control of breathing.
14
Vick, Tyler J. "Geometry Modeling and Adaptive Control of Air-Breathing Hypersonic Vehicles." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1397468045.
Повний текст джерела
15
Hait, Aaron Vincent. "Is breathing control an effective coping strategy for public speaking anxiety?" Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/31015.
Повний текст джерелаАнотація:
Two studies were conducted to determine whether controlled, abdominally-predominant breathing could be accurately implemented during periods of acute anxiety by speech anxious/phobic individuals, and what effect breathing control has on autonomic and subjective indices of anxiety. Twenty-two moderately speech anxious young adults took part in Study 1. The results of this study indicated that after two weeks of training, only 50% of trainees were able to implement the controlled breathing technique with any degree of accuracy while waiting to deliver an impromptu speech before a small audience. No one were successful at reliably implementing the technique during the speech itself. As in previous research, training had little impact on autonomic arousal but was associated with improvements in self-reported anxiety. Similar findings emerged for Study 2, which differed from Study 1 in that it involved a larger (N = 48) and more highly speech anxious sample who participated in a longer (4-week), more intensive training program. Although training had little effect on subjective or autonomic arousal during speech anticipation and speech delivery, it did result in significantly higher predictions of speech aptitude and emotional control relative to no treatment. Such findings suggest that breathing control is not a useful emotion-focused coping strategy on its own, but may add to the effectiveness of exposure-based therapies by enhancing patients' self-efficacy and willingness to expose themselves to feared situations.Arts, Faculty of
Psychology, Department of
Graduate
16
Harris, Michael Bruce. "Control of breathing in the golden-mantled ground squirrel (Spermophilus lateralis)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ27157.pdf.
Повний текст джерела
17
Kuipers, Irene Mariëtte. "Mechanisms involved in the control of breathing before and after birth." Maastricht : Maastricht : Rijksuniversiteit Limburg ; University Library, Maastricht University [Host], 1995. http://arno.unimaas.nl/show.cgi?fid=5765.
Повний текст джерела
18
Brady, Emer Margaret. "Investigating the relationship between sleep disordered breathing, glycaemic control and inflammation." Thesis, University of Leicester, 2009. http://hdl.handle.net/2381/9926.
Повний текст джерелаАнотація:
Metabolic Syndrome (MetS), Type 2 Diabetes (T2DM) and obesity related sleep disorders like Sleep Disordered Breathing (SDB) share common features including visceral adiposity, impaired glycaemic control and increased cardiovascular disease (CVD) risk. As sub-clinical inflammation is considered a key player in these conditions they are thought to be interrelated. We aimed to further investigate this putative interrelationship. In a multi-ethnic population with a spectrum of glucose tolerance (sub-study of the ADDITION-study), we report that abdominal obesity underpins the association between SDB and systemic inflammation. South Asians with SDB had significantly higher levels of leptin, poorer glycaemic control but lower levels of oxidative stress than their Caucasian counterparts. These data suggest that the pathogenesis of SDB is different between these ethnic groups and may aid in understanding why South Asians are at increased risk of T2DM and CVD. Furthermore, SDB is independently associated with increased likelihood of MetS. However, no differences in cardiovascular markers, inflammatory biomarkers or anthropometric measures were observed between those with excessive daytime sleepiness or sleep disturbances as determined by the Epworth Sleepiness Scale and the Sleep Assessment Questionnaire, respectively. This suggests that these questionnaires are broad and insensive in identifying these sleep parameters. Obstructive Sleep Apnoea (OSA) is a severe form of SDB which can be successfully treated with Continuous Positive Airway Pressure (CPAP). Reported results on the effects of CPAP therapy on glycaemic control are inconsistent thus no difinative conclusion could be made from the systematic review carried out to answer this research question. Thus 'The Leicester Sleep and Sugar Study' was conducted to further establish whether CPAP-therapy impacts glycaemic control or systemic inflammation in subjects with established T2DM and newly diagnosed OSA. We report a clinically significant improvement in glycaemic control (HbA1c -0.8%) and a significant reduction in waist circumference with improved psychological well being 6 months post CPAP-therapy. It is evident that OSA is associated with T2DM and MetS although the direction of cause and effect has not been elucidated to date. The results reported here suggest that OSA negatively impacts on glycaemic control. Additionally we report a possible ethnic difference in the pathophysiology of SDB with inflammation playing a key role. Further research is required in this area to further establish these findings.
19
Groves, Kevin. "Modelling, simulation, and control design of an air-breathing hypersonic vehicle." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1302726196.
Повний текст джерела
20
Jaiswal, Stuti J. "The Consequences of Developmental Nicotine Exposure on Neonatal Central Respiratory Control." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/293608.
Повний текст джерелаАнотація:
Developmental nicotine exposure (DNE) exerts negative consequences on the CNS via the activation of nAChRs that are available early and widely throughout development (refs). In this work, we examined how DNE changed excitatory and inhibitory neurotransmission in brainstem regions involved in central breathing control. Previous work using the brainstem-spinal cord preparation had shown that DNE augmented the respiratory-related response to AMPA, muscimol (a GABAA agonist), and glycine (Luo et al., 2004; Luo et al., 2007; Pilarski and Fregosi, 2009a). These studies used a split-bath preparation in which a drug (AMPA, muscimol, or glycine) was applied to medulla, and the frequency of the respiratory response (in the form of spontaneous, rhythmic bursting activity) was recorded from cervical nerve 4 (C4), which provides output to the diaphragm. Although these studies showed that DNE AMPA, GABA(A), and glycine neurotransmission in the medulla, the regions mediating the effect and the mechanism of DNE's action remained unclear. In this study we tested the hypothesis that the observed changes in respiratory burst frequency were mediated through the preBötzinger complex (preBötC), and the mechanism of enhanced activity involved an upregulation of neurotransmitter receptors. Additionally, we were interested in studying the effect of DNE on breathing-related motor pools, and therefore studied DNE's effect on excitatory and inhibitory neurotransmission in the XIIMN. We approached these questions and aims using a combination of techniques, including extracellular recordings from whole nerve output in rhythmic brainstem slices, immunohistochemistry, and Western blotting. We found enhanced AMPA, GABA(A), and glycine neurotransmission in the XIIMN and preBötC, and varying changes in neurotransmitter receptor expression in both groups. Additionally, we found a decrease in motoneuron soma size in XII motoneurons that stained positively for the glycine receptor. Overall, this study shows that DNE alters inhibitory and excitatory neurotransmission in both the preBötC and XIIMN, and that these changes may be mediated through a combination of change in cell size and receptor expression.
21
Singh, Ashish. "Autoreceptor control of 5-HT release from central serotoninergic neurones." Thesis, University of Bath, 1990. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278201.
Повний текст джерела
22
Hopwood, Sarah Elizabeth. "Control of serotonin release in the dorsal and median raphe nuclei." Thesis, Queen Mary, University of London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369264.
Повний текст джерела
23
Krueger, Katherine C. "Transcriptional Regulation of FEV, a Human Serotonin Neuron Developmental Control Gene." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1231289529.
Повний текст джерела
24
Webb, Cheryl Lynn. "Aspects of the control of breathing in the golden-mantled ground squirrel." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26662.
Повний текст джерелаАнотація:
Spermophilus lateralis, the golden-mantled ground squirrel, while euthermic exhibits a strong hypoxic ventilatory response, but a relatively blunted hypercapnic ventilatory response similar to other semi-fossorial mammals. Under resting conditions, carotid body
chemoreceptors provide a tonic excitatory input to the frequency component of ventilation. Carotid body
denervation (CBX) results in a 40% decrease in minute ventilation (V). The overall ventilatory response to hypoxia is unaffected by CBX, although the ventilatory threshold is significantly shifted to lower levels of inspired O₂. CBX also has little effect on the overall response to hypercapnia. Thus, in S. lateralis, it appears that changes in the partial pressure of O₂ (P0₂) In the blood act centrally, rather than peripherally, to play a predominate role in ventilatory control.
Chronic exposure to hypoxia and hypercapnia (CHH, 17% O₂ and 4% CO₂) does not result in overall ventilatory acclimation, with minute ventilation being similar to control squirrels acutely exposed to hypoxic and hypercapnic conditions. In spite of this, CHH exposure does result in adjustments to respiration; frequency is decreased and tidal volume is elevated compared to control squirrels acutely exposed to CHH conditions. Overall V sensitivities to both hypoxia and hypercapnia are not significantly altered by CHH exposure. It appears that acclimation to chronic hypoxic and hypercapnic conditions in S. lateralis may increase alveolar minute ventilation relative to total minute ventilation and thus minimize the changes in arterial PO₂ and Pco₂ during hypoxic and hypercapnic exposure.
During entrance into hibernation, as metabolic rate and body temperature decline, concomitant decreases in ventilation occur. Two patterns of respiration occur during deep hibernation; a burst breathing pattern characterized by long non-ventilatory periods (Tnvp) separated by bursts of several breaths and a single breath pattern characterized by single breaths separated by a relatively short Tnvp.
In S. lateralis during hibernation at body temperatures between 6° and 10°C, a burst breathing pattern prevails. At slightly lower body temperatures, less than 4°C, a single breath breathing pattern prevails. Both burst breathing and single breath breathing squirrels have similar overall levels of resting minute ventilation. Burst breathing squirrels exhibit a significant respiratory response to hypoxia (3% O₂) and when the decreases in metabolic rate during hibernation are taken into account (air convection requirement) their hypoxic sensitivity is similar to that in awake S. lateralis. In contrast, single breath breathing squirrels do not respond to hypoxia at any level tested (down to 3% O₂). Both burst breathing and single breath breathing squirrels show large ventilatory repsonses to hypercapnia. In the burst breathing state hypercapnic sensitivity is significantly higher compared to the single breath breathing state, due to an augmented frequency response during burst breathing. In both groups of hibernating squirrels ventilation is increased during hypercapnia solely by decreases in the nonventilatory period. When ventilation is standardized for the decreases in metabolic rate during hibernation both burst breathing and single breath breathing S. laterlis exhibit a much higher hypercapnic sensitivity than that seen in awake S. lateralis. Carotid body denervation has little effect on ventilatory pattern generation or ventilatory sensitivities to hypoxia and hypercapnia in hibernating squirrels.
It appears that during hibernation in S. lateralis, ventilation is controlled primarily by changes in the partial pressure of CO₂ (Pc0₂) in tne blood acting centrally to stimulate ventilation. The burst breathing pattern is produced centrally, as are the respiratory responses to hypoxia and hypercapnia. Thus, central mechanisms involved with ventilatory control are extremely important in both the euthermic state and the hibernating state, but the chemical stimuli regulating ventilation appear to be fundamentally different in euthermic and hibernating S. lateralis.Science, Faculty of
Zoology, Department of
Graduate
25
Richard, Normand André. "Control of breathing and cardio-respiratory response to normobaric and hypobaric hypoxia." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43103.
Повний текст джерелаАнотація:
We examined the control of breathing, cardio-respiratory effects and the prevalence of acute mountain sickness (AMS) in humans exposed to hypobaric hypoxia (HH), normobaric hypoxia (NH), and under two control conditions (hypobaric normoxia and normobaric normoxia). Subjects (n = 11) were familiarised with all tests prior to their first exposures. The order of conditions was randomized, each exposure lasted for 6 hours, and consecutive exposures were separated by a one-week washout period. Prior to and following exposures, subjects underwent hyperoxic and hypoxic Duffin rebreathing tests, measuring CO₂ threshold and sensitivity, and a hypoxic ventilatory response test (HVR), measuring sensitivity to O₂. Inside the environmental chamber, minute ventilation (VE), tidal volume (VT), frequency of breathing (fB), blood oxygenation (SPO₂), heart rate (HR) and blood pressure (BP) were measured at 5min, 30min and hourly until exit. Symptoms of AMS were evaluated hourly using the Lake Louise score (LLS). Both the hyperoxic and hypoxic CO₂ thresholds were lowered after HH and NH during the Duffin rebreathing test. Hypoxic sensitivity in the Duffin rebreathing test was only increased after HH exposure. No changes occurred in the HVR after any of the four exposures. Ventilatory parameters, SPO₂ and HR were higher in the hypoxic exposures as opposed to the normoxic exposures. No major differences were observed for VE or any other cardio-respiratory variables between NH than HH. The LLS was greater in AMS-susceptible than in AMS-resistant subjects, but LLS was similar in HH and NH. We conclude that 6 hours of hypoxic exposure is sufficient to lower the peripheral and central CO₂ threshold, but it is too short in duration to induce differences in cardio-respiratory variables between HH and NH or to create differences in AMS severity.
26
Cooper, Susan Elizabeth. "Clinical trials to investigate the effect of breathing exercises on asthma control." Thesis, University of Nottingham, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.537620.
Повний текст джерела
27
Moore, P. J. "The involvement of peripheral chemoreceptors in the control of fetal breathing movements." Thesis, University of Reading, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233658.
Повний текст джерела
28
Pandit, Jaideep Jagdeesh. "The effects of exercise on the chemical control of breathing in man." Thesis, University of Oxford, 1993. http://ora.ox.ac.uk/objects/uuid:09156247-2a9b-4c25-b51a-7b3669d6319e.
Повний текст джерелаАнотація:
This thesis is concerned with the chemical control of breathing during exercise in humans. Chapter 1 reviews some of the relevant studies in animals and humans. Chapter 2 describes the experimental apparatus and the technique of dynamic end-tidal forcing performed using a computer-controlled gas-mixing system. Chapter 3 describes a study of the effects of sustained hypoxia on ventilation during steady exercise. The acute ventilatory response to hypoxia (AHR) was increased during exercise as compared with rest, but the magnitude of the subsequent decline in ventilation (HVD), expressed as a fraction of the AHR, was reduced. A simple model of the hypoxic peripheral chemoreflex is proposed, in which the mechanisms underlying AHR and HVD are functionally separate and can be independently modulated by external factors. Chapter 4 assesses changes in peripheral chemoreflex sensitivity to hypoxia in terms of the degree of decline in AHR measured in the resting periods shortly after prior conditioning periods of hypoxia and/or exercise. At rest, a second AHR measured 6 min after a period of sustained hypoxia had declined by 30% as compared with the initial AHR. In contrast, the AHR measured in the resting period after a period of sustained hypoxic exercise was only 11% smaller in magnitude than the AHR measured after a period of euoxic exercise. The results suggest that the degree to which hypoxic sensitivity declines during sustained hypoxia is genuinely attenuated, rather than masked, by exercise. Chapter 5 describes the changes in respiration during prolonged exercise breathing air with and without added CO2. During prolonged poikilocapnic exercise, ventilation remained constant, but metabolic CO2 production, respiratory quotient and end-tidal PCO2 declined; a result which suggests that in man, ventilation can be dissociated from the CO2 flux. During hypercapnic exercise, ventilation progressively increased; this was interpreted as being due to a correction by end-tidal forcing of the natural tendency for end-tidal CO2 to decline, together with an independent effect of CO2 per se on the ventilation. Chapter 6. Electrical muscle stimulation was used as means of inducing non-volitional exercise. Electrically-induced exercise increased the AHR as compared with rest, and with voluntary exercise at matched external work rate. The AHRs during electrical stimulation and voluntary exercise matched to the internal work rate were similar. Chapter 7. Electrical muscle stimulation was used in paraplegic subjects in whom there would be no neural control of exercise. Electrically-induced exercise increased the AHR as compared with rest. When compared with the data from Chapter 6, the results suggest that the observed increase in AHR during normal voluntary exercise can be wholly accounted for by the increase in metabolic CO2 production, or closely related factors. Chapter 8 presents a brief summary of the findings in this thesis.
29
Hennessy, Morgan Lorraine. "Function-Specific Serotonergic Neurons in the Control of Breathing and Body Temperature." Thesis, Harvard University, 2015. http://nrs.harvard.edu/urn-3:HUL.InstRepos:23845412.
Повний текст джерелаАнотація:
The control of respiration and body temperature involves neural circuits within the brainstem modulated by the neurotransmitter serotonin (5HT), though it is unclear precisely which serotonergic neurons are critical to these functions. Recent work from our laboratory and others has demonstrated considerable heterogeneity among serotonergic neurons – in their projection targets, expressed genes, and developmental origin – which we hypothesize reflects the subserving of distinct functions by distinct serotonergic neuron subtypes. More specifically, our laboratory has parsed molecular subtypes of serotonergic neurons by their co-expression of the pan-serotonergic gene Pet1 along with a marker gene. When partnered with intersectional genetic tools, selective access to each subtype for functional study is enabled. Through application of these tools, we have identified a subtype of serotonergic neuron, designated the Egr2-Pet1 subtype, which modulates the CO2 breathing reflex and projects to CO2 chemosensory brain centers. Here, we describe a new molecular subtype of serotonergic neuron, defined by Tachykinin 1 (Tac1) expression, that projects to respiratory motor nuclei. Upon silencing the Tac1-Pet1 subtype, we show that it, too, modulates the CO2 breathing reflex, but presumably by affecting respiratory motor output. Thus, two discrete subtypes of serotonergic neurons modulate breathing: one involved in sensory processing and the other involved in motor output, reflecting an unexpected division of serotonergic labor along the motor-sensory axis. In parallel, we tested the contribution of serotonergic neuron subtypes to body temperature modulation, as we have previously shown that en masse acute silencing of serotonergic neurons leads to hypothermia. We provide evidence that serotonergic neurons within the median raphe and raphe pallidus may contribute to this task. In these studies, we manipulated serotonergic neuron activity via hM4Di-mediated hyperpolarization using the intersectional allele RC::FPDi, for which parameters were optimized and defined. In summary, we have identified molecularly and functionally distinct subtypes of serotonergic neurons necessary for normal homeostatic regulation. Results may shed light on homeostatic disorders involving 5HT, such as sleep apnea and sudden infant death syndrome, as well as inform strategies for potentially minimizing homeostatic side effects of present 5HT-affecting therapeutics.Medical Sciences
30
Szpak, Benjamin R. "Aerothermoelastic considerations for a control surface on an air-breathing hypersonic vehicle." Connect to resource, 2009. http://hdl.handle.net/1811/37034.
Повний текст джерела
31
Quérée, Philip. "Feedback control in the central 5-HT system : evidence for a role of 5-HT₂c receptors." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670061.
Повний текст джерела
32
Scheiner, Ricarda, Arnd Baumann, and Wolfgang Blenau. "Aminergic control and modulation of honeybee behaviour." Universität Potsdam, 2006. http://opus.kobv.de/ubp/texte_eingeschraenkt_verlag/2010/4610/.
Повний текст джерелаАнотація:
Biogenic amines are important messenger substances in the central nervous system and in peripheral organs of vertebrates and of invertebrates. The honeybee, Apis mellifera, is excellently suited to uncover the functions of biogenic amines in behaviour, because it has an extensive behavioural repertoire, with a number of biogenic amine receptors characterised in this insect. In the honeybee, the biogenic amines dopamine, octopamine, serotonin and tyramine modulate neuronal functions in various ways. Dopamine and serotonin are present in high concentrations in the bee brain, whereas octopamine and tyramine are less abundant. Octopamine is a key molecule for the control of honeybee behaviour. It generally has an arousing effect and leads to higher sensitivity for sensory inputs, better learning performance and increased foraging behaviour. Tyramine has been suggested to act antagonistically to octopamine, but only few experimental data are available for this amine. Dopamine and serotonin often have antagonistic or inhibitory effects as compared to octopamine. Biogenic amines bind to membrane receptors that primarily belong to the large gene-family of GTP-binding (G) protein coupled receptors. Receptor activation leads to transient changes in concentrations of intracellular second messengers such as cAMP, IP3 and/or Ca2+. Although several biogenic amine receptors from the honeybee have been cloned and characterised more recently, many genes still remain to be identified. The availability of the completely sequenced genome of Apis mellifera will contribute substantially to closing this gap. In this review, we will discuss the present knowledge on how biogenic amines and their receptor-mediated cellular responses modulate different behaviours of honeybees including learning processes and division of labour.
33
Villiger, Carmel G. "Investigations into transient respiratory control using the work rate of breathing and a non-linear breather." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-02132009-170901/.
Повний текст джерела
34
Chichka, David F. "Cruise-dash optimization applied to an air-breathing missile." Thesis, Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/90923.
Повний текст джерелаАнотація:
The method of singular perturbations is applied to the determination of the optimal range-fuel-time trajectory for an air-breathing missile. This method is shown to lead to the reduced-order "cruise-dash" model, and this model is used in the optimization study. Earlier work in this area is extended by the inclusion of two not heretofore considered limits on the dynamical system.
The results of the earlier work are shown to hold throughout much of the velocity regime in which the missile operates, but operation in the very high and very low velocity ranges is shown to be sharply curtailed, with the optimal operating points being changed drastically in some cases. Also, the effect of the non-zero minimum admissible throttle setting and the resultant throttle-chattering on the solution of the control problem is examined in some detail.M.S.
35
Zhang, Weirong. "Role of the dorsal periaqueductal gray activation in the neural control of breathing." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0008261.
Повний текст джерелаАнотація:
Thesis (Ph.D.)--University of Florida, 2004.Typescript. Title from title page of source document. Document formatted into pages; contains 127 pages. Includes Vita. Includes bibliographical references.
36
Moosavi, Syed Shakeeb Hassan. "The significance of behavioural (non-automatic) factors in the ventilatory response to exercise in man." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267486.
Повний текст джерела
37
Oldman, Anna Dorothy. "The role of serotonin in the control of mood and appetite in humans." Thesis, University of Oxford, 1994. http://ora.ox.ac.uk/objects/uuid:d2315835-59d5-4e7d-a157-0749e95f27c5.
Повний текст джерелаАнотація:
This thesis addresses the effects of pharmacological manipulations of brain 5- hydroxytryptamine (5-HT, serotonin) and it's precursor, tryptophan, on appetite and mood in humans. Chapter 1 is a presentation of the literature reviewed in order to carry out the studies contained within this thesis. General methods are described in Chapter 2; these include biochemical methods for analysis of plasma tryptophan, and measures and assessment methodologies for analysis of appetite and mood. This chapter also contains a pilot study of the methodology adopted for lowering plasma tryptophan levels. The first experiment (Chapter 3) examines the effects of calorie controlled dieting on plasma tryptophan, mood and appetite using a longitudinal design. Dieters were compared with a matched control group, and the results demonstrated that whilst dieting does not appear to alter mood or responses to food in a laboratory setting, it does lower levels of plasma tryptophan compared with baseline and with controls. In view of the confounding variables of dieting on mood and appetite, the second experiment (Chapter 4) examined the effects of an acute, laboratory based depletion of plasma tryptophan on these parameters in healthy female volunteers acting as their own controls. Significant depletion of plasma tryptophan was not associated with alterations in mood or appetite. The third experiment (Chapter 5) addresses the issue of predisposing factors in the effects of tryptophan depletion on mood and appetite. This was carried out with a group of women who had recovered from an eating disorder (bulimia nervosa). These subjects were acting as their own controls but were also compared directly with the non-clinical group of subjects from the previous experiment. This experiment demonstrated interesting differences in the eating behaviour of the two groups, and a significant difference in baseline levels of total plasma tryptophan. There were, however, no effects of tryptophan depletion on mood or appetite in the women who had recovered from bulimia nervosa. In view of the apparent lack of effect of tryptophan depletion on mood or appetite, the remaining two experiments examine the role of specific 5-HT receptor subtypes in the control of appetite. Chapter 6 examines the effect of meta-chlorophenylpiperazine (mCPP), a 5-HT2C receptor agonist on appetite, and Chapter 7 examines the effect of 5-HT3 receptor blockade on amphetamine anorexia. Whilst the data from these experiments do not support a role for these receptor subtypes in appetite, it is suggested that this is a potentially fruitful area for future research. The results generated by the above experiments are discussed in Chapter 8 in the light of other research findings. The methodologies adopted for these experiments and the implications of these studies for future research are discussed.
38
Honig, Gerard. "Physiological effects of SSRI administration: Negative feedback control of serotonin production and release." Diss., Search in ProQuest Dissertations & Theses. UC Only, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3352475.
Повний текст джерела
39
Kelly, Bronwen Noreen. "The Coordination of Breathing and Swallowing Across the Human Lifespan: Implications for Neural Control." Thesis, University of Canterbury. Communication Disorders, 2006. http://hdl.handle.net/10092/1295.
Повний текст джерелаАнотація:
Our understanding of the neural control of breathing-swallowing coordination (BSC) is largely unclear. Although brainstem control is undoubtedly predominant, this research investigated the hypothesis that the cortex becomes increasingly influential in BSC between birth and adulthood. The main paradigm used to test this primary hypothesis was a comparison of BSC in conditions along a continuum of volitional through non-volitional swallowing on the basis of a decreasing level of cortical activation along this continuum. Voluntarily-initiated swallows during wakefulness were at one end of the continuum and reflexively-initiated swallows during sleep were at the other extreme. Non-volitional wakeful swallows were considered between these two conditions. The BSC of ten infants between birth and 1 year of age and twenty adults between the ages of 20 and 75 years was recorded using non-invasive time-locked recording methods. In order to apply the 'continuum-of-volition' paradigm to swallowing conditions in infants, BSC was monitored during nutritive (breast- or bottle-feeding), non-nutritive wake, and sleep swallows. Infants were monitored longitudinally to determine whether maturation of the cortex and corticobulbar tracts during the first year of life influenced the patterns of BSC. In adults, BSC was monitored during three non-nutritive conditions: volitional, spontaneous wake, and sleep conditions. Post-swallow expiration was found to be predominant in all conditions for all participants at all ages. In addition, the infant results revealed that nutritive BSC matured during the first year of life and differed to non-nutritive wakeful BSC, particularly in the first 2 months of life. Non-nutritive wakeful and sleep BSC did not differ from one another. In summary, the infant results support increasing cortical input into volitional nutritive BSC, an early impact of feeding on BSC, and no difference between BSC when asleep and non-volitional non-nutritive swallows when awake. The results obtained from adults revealed that irrespective of the level of arousal, volitional BSC is different to non-volitional BSC. These results imply that cortical influence on BSC is limited to conditions in which swallowing is voluntarily initiated. The combined interpretation of infant and adult results suggest that cortical influence over BSC, although increasing with maturation, is limited to the volitional swallowing conditions of feeding in infants and during non-nutritive but volitional swallows in adults. From this, it can be deduced that the most likely cortical sites involved in BSC are those involved in the voluntary initiation or planning of swallowing. Infant and adult swallowing apnoea duration (SAD) was also compared across all of the above conditions. SAD was influenced by feeding throughout the first year of life but was not influenced by level of arousal at any stage in the first year or in adulthood. Also, SAD did not change with age in any swallowing condition during infancy. However, comparison of non-nutritive wake SAD across the lifespan revealed that SAD of newborns and young adults is shorter than that of elderly adults, with no difference between consecutive age-groups: newborns, one-year-olds, and young adults. These results suggest SAD is largely mature at birth and impervious to descending suprabulbar influence. Finally, the effects of volitional swallowing and level of arousal on peak submental surface electromyography (SEMG) was investigated in adults. Like BSC, submental muscle activity was influenced only by volitional swallowing, being longer for volitional than non-volitional swallows without being influenced by level of arousal. Since peak submental SEMG activity represents a measure of relative hyolaryngeal excursion, these results suggest that the cortex has some degree of influence over this particular feature of pharyngeal-stage swallowing.
40
Roos, Warren C. "Modeling and Analysis of Air Breathing Hydrogen-Based PEM Fuel Cells." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1302184046.
Повний текст джерела
41
Rieger-Fackeldey, Esther. "Regulation of Breathing under Different Pulmonary Conditions." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4671.
Повний текст джерела
42
Andreatta, Gabriele. "Dormancy awakened: aminergic control of diapause in Drosophila." Doctoral thesis, Università degli studi di Padova, 2015. http://hdl.handle.net/11577/3424143.
Повний текст джерелаАнотація:
Coping with adverse environmental conditions is one of the most crucial challenges for all living beings. The coupling between external cues and hormonal signaling is key to allow survivorship of individuals and insects in particular have been intensively studied to better understand this connection. Although the hormonal cascade that promotes insect development and reproduction is well known (insulin signaling - juvenile hormone – 20-Ecdysone), how this neuroendocrine axis is modulated by environmental stimuli remains still largely elusive. To deepen the molecular features of IIS-JH-20E axis regulation, we focused our attention on one of the best examples of physiological strategies triggered by environmental stimuli, diapause. Diapause is an inducible developmental arrest, which characterizes the life cycle of several species, from Caenorhabditis elegans to mammals. Our results shed new light on the regulation of key neuroendocrine pathways for growth and development, and suggest how organisms couple environmental conditions with inner hormonal physiology.Sopravvivere a drastici cambiamenti climatici rappresenta una delle sfide principali per gli esseri viventi. Gli insetti non solo forniscono esempi straordinari di adattamenti morfologici e fisiologici a climi sfavorevoli, ma sono anche molto studiati per comprendere quali sono i meccanismi molecolari responsabili di questi adattamenti. Negli insetti, i principali processi ormonali che promuovono lo sviluppo e la riproduzione sono ben noti e comprendono tre attori principali, il segnale insulinico (IIS), l’ormone giovanile (JH) e l’idrossi-ecdisone (20E). Nonostante questo importante asse neuroendocrino (IIS-JH-20E) sia ben studiato, poco si conosce riguardo i meccanismi molecolari che trasducono le informazioni ambientali ai componenti fondamentali del sistema endocrino, modulandone l’attività regolatoria. Per questo abbiamo rivolto la nostra attenzione ad uno degli esempi più interessanti di strategie fisiologiche evocate dagli stimoli esterni, la diapausa, un arresto dello sviluppo inducibile che rappresenta un evento estremamente diffuso nel regno animale. I nostri risultati forniscono un contributo alla comprensione degli aspetti regolativi dei meccanismi neuroendocrini fondamentali per la crescita, lo sviluppo e la riproduzione, e suggeriscono alcune modalità con le quali gli insetti accoppiano la percezione delle condizioni ambientali con la loro fisiologia ormonale.
43
Alex, Katherine D. "5-HT2C SEROTONIN RECEPTORS: CELLULAR LOCALIZATION AND CONTROL OF DOPAMINERGIC PATHWAYS IN THE RAT BRAIN." Connect to text online, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1164766901.
Повний текст джерела
44
Dryden, Simon. "Neuropeptide Y and serotonin in the rat hypothalamus : interactions and the control of energy homoeostasis." Thesis, University of Liverpool, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262333.
Повний текст джерела
45
Karlsson, Caroline. "Direct and endothelium-linked serotonergic control of vascular tone in human uterine and umbilical arteries." Lund : Dept. of Obstetrics and Gynaecology, University of Lund Malmö University Hospital, 1998. http://catalog.hathitrust.org/api/volumes/oclc/40420934.html.
Повний текст джерела
46
McKay, Leanne Campbell. "The neural basis for the control of breathing in humans determined using functional magnetic resonance imaging." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271127.
Повний текст джерела
47
Mannava, Anusha. "Adaptive Control of Nonminimum Phase Aerospace Vehicles- A Case Study on Air-Breathing Hypersonic Vehicle Model." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1503265018577074.
Повний текст джерела
48
DiLorenzo, Paul Carmen. "Breathing, laughing, sneezing, coughing model and control of an anatomically inspired, physically-based human torso simulation /." Diss., [Riverside, Calif.] : University of California, Riverside, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3350078.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of California, Riverside, 2009.Includes abstract. Title from first page of PDF file (viewed January 28, 2010). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 100-106).
49
Wollman, Lila Buls, and Lila Buls Wollman. "Plasticity of Brainstem Motor Systems in Response to Developmental Nicotine Exposure." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/626307.
Повний текст джерелаАнотація:
Developmental nicotine exposure (DNE) is known to cause abnormal development of multiple brain regions and results in impaired control of breathing and altered behaviors that rely on proper coordination of the muscles of the tongue. The adverse effects of nicotine are presumably caused by its actions on nicotinic acetylcholine receptors (nAChRs), which modulate fast-synaptic transmission and play a prominent role during brain development. Previous work has shown that DNE alters nAChR function in multiple brainstem regions (Pilarski et al., 2012, Wollman et al, 2016). Moreover, DNE causes multiple changes to XIIMNs, which innervate the muscles of the tongue (Powell et al., 2016, Powell et al., 2015, Pilarski et al., 2011). These changes likely reflect both altered development as a primary outcome of the chronic presence of nicotine, as well as, homeostatic adjustments made in an attempt to maintain normal motoneuron output. With the experiments described here, we tested the hypothesis that DNE alters the development of fast-synaptic transmission to XIIMNs, which, along with intrinsic properties of these neurons, is a main determinant of motor output to the muscles of the tongue. Additionally, we tested the hypothesis that DNE alters the function of nAChRs located on multiple brainstem neurons, including those that modulate fast-synaptic transmission to XIIMNs. For these experiments, we used whole cell patch clamp recordings from XIIMNs in a transverse slice of the medulla, and extracellular recordings from the 4th cervical ventral root in the brainstem spinal cord, split bath preparation. All preparations were obtained from control or DNE neonatal rats in the first week of life. Overall, the results of these experiments show that DNE alters fast-synaptic transmission to XIIMNs, which likely reflects appropriate homeostatic adjustments aimed at maintaining normal motor output at rest. However, these results also show that nAChR function is significantly altered by DNE, indicating fast-synaptic transmission may not be appropriately modulated in response to increased release of acetylcholine (ACh), the endogenous neurotransmitter for nAChRs.
50
Cardoso, Maria da Conceição Alves. "Active cycle breathing techniques como técnica de higiene brônquica na asma: estudo piloto." Master's thesis, Faculdade de Ciências Médicas. Universidade Nova de Lisboa, 2011. http://hdl.handle.net/10362/6986.
Повний текст джерелаАнотація:
RESUMO: Relevância e Objectivos: O objectivo deste estudo consistiu em verificar a
eficácia e segurança de uma técnica de higiene brônquica – Active Cycle
breathing technique (ACBT), na remoção de secreções e desinsuflação em crianças asmáticas. É uma técnica recente, que ainda não foi estudada nesta população.
Metodologia: A amostra foi constituída por um total de 14 crianças, com idades
compreendidas entre os 6 e 18 anos, com o diagnóstico de asma. Foi dividida em dois grupos: grupo de controlo, constituído por asmáticos estáveis e grupo experimental constituído por asmáticos pós-crise. Ambos receberam o mesmo tratamento, que consistiu numa única sessão de ACBT. Realizaram um exame da função respiratória (variáveis FEV1, PEF, MEF75%, RV e FRC) antes e após
a aplicação da técnica. Mediu-se a Saturação de O2 antes, a meio e no fim da aplicação da técnica. Por último, pesaram-se as secreções recolhidas durante a sessão de tratamento.
Resultados: Como resultados, quando omparamos o antes e após aplicação do ACBT, obtivemos diferenças significativas no RV (p <0,05) e FRC (p <0,05); muito significativa na Sa02 (p <0,01) e peso de secreções, nos asmáticos pós crise. Ocorreu uma melhoria significativa da saturação (p <0,05) em asmáticos estáveis, não havendo secreções. Não houve efeitos adversos nem broncoespasmo em ambos os grupos.Conclusão: O ACBT é uma técnica que promove a remoção de secreções e
diminuição da insuflação na população de asmáticos.--------------------ABSTRACT:Relevance and Goals: the goal of this study was to verify the efficiency and security of a bronchial hygienic technique - Active Cycle Breathing Technique (ACBT) – in the obstruction and insufflation of asthmatic children. This is a new technique that has not yet been studied in this population.
Procedures: The subjects were 14 children aged between 6 and 18 years old with asthma diagnosis. They were divided in two groups: the control group with stable asthmatics and the experimental group with post-crisis asthmatics. Both received the same treatment that was a single session of ACBT. They made a lung function test before and after the application of the technique (variables
FEV1, PEF, MEF75%, RV and FRC). The level of O2 saturation was measured before, during and after the procedure. In the end, the secretions collected during the treatment were weighted.
Results: We observed a significant difference on RV (p ˂0,05), FRC (p ˂0,05),
Sa02 (p ˂0,01) and in the weight of the secretions in the post-crisis asthmatics
after ACBT. There was a significant improvement of saturation (p ˂0,05) only in
the stable asthmatics. There were no adverse effects or bronchospasm in both groups.