Despite dramatic morphological differences between animals from different taxa, several important features in organization and sensory system processing are similar across animals. Because of this similarity, a number of different organisms including mammals, insects, and decapod crustaceans serve as valuable model systems for understanding general principles of environmental effects. This research examines intrinsic and extrinsic factors by behaviorally and physiologically means to identify the impact of environmental conditions on two distinct crayfish species- Procambarus clarkii (surface) and Orconectes australis packardi (cave). The research identified behavioral and physiological responses in these two morphological and genetically distinct species. The studies also examined multiple levels of complexity including social behavior, an autonomic response, chemosensory capabilities and neuronal communication, identified comparative similarities/differences, addressed learning and environmental influences on learning and examined behavioral and cellular responses to high levels of carbon dioxide. I found environmental factors directly influence crayfish behavior of social interactions. Interactions were more aggressive, more intense and more likely to end with a physical confrontation when they took place 'in water' than 'out of water'. The modified social interaction resulted in a altered fighting strategy. A study on motor task learning was undertaken which showed similar learning trends among these crayfish species despite their reliance on different sensory modalities. I also demonstrated learning was dependent on perceived stress by the organism. Previously trained crayfish inhibited from completing a task showed significant increase in an autonomic stress response. Studies on the behavioral and physiological responses to CO2 revealed that high [CO2] is a repellent in a concentration dependent manner. The autonomic responses in heart rate and an escape tailflip reflex shows complete cessation with high [CO2]. A mechanistic effect of CO2 is by blocking glutamate receptors at the neuromuscular junction and through inhibition of the motor nerve within the CNS.

Su kvėpavimu yra susiję daug organizmo fiziologinių sistemų, ypač širdies ir kraujagyslių sistema. Įvairūs kvėpavimo pratimai yra plačiai taikomi tiek sporte, tiek reabilitacijoje kaip veiksnys veikiantis į organizmo funkcinę būklę. Todėl įdomi ir aktuali yra mokslinė problema, ar specialiai taikomi kvėpavimo pratimai turi įtakos širdies ir kraujagyslių sistemos funkciniams rodikliams ir jų kaitai fizinių krūvių metu. Tyrimo objektas – širdies ir kraujagyslių sistemos funkciniai rodikliai ir ypatybės atliekant kvėpavimo pratimus. Hipotezė: manome, kad specialiai taikomi kvėpavimo pratimai turi teigiamos įtakos širdies ir kraujagyslių sistemos funkciniams rodikliams ir jų kaitai atliekant fizinius pratimus. Darbo tikslas: nustatyti širdies susitraukimo dažnio kaitos ypatybes atliekant kvėpavimo pratimą, jungiantį hiperventiliaciją ir kvėpavimo sulaikymus. Uždaviniai: 1. Nustatyti ŠSD ir elektrokardiogramos intervalų JT ir RR santykio kaitos ypatybes aktyvios hiperventiliacijos ir kvėpavimo sulaikymų metu. 2. Nustatyti ar kinta širdies ir kraujagyslių sistemos funkcinės būklės rodiklių pasikeitimo laipsnis reaguojant į pakartotinas hiperventiliacijas ir kvėpavimo sulaikymus. 3. Nustatyti nuovargio įtaką ŠKS funkcinės būklės rodiklių kaitai atliekant kvėpavimo pratimą jungiantį hiperventiliaciją ir kvėpavimo sulaikymus. Tyrimo metodai ir organizavimas: 1. Elektrokardiografija; 2. Arterinio kraujo spaudimo matavimas; 3. Fizinio krūvio mėginiai. Tyrimas atliktas LSU... [toliau žr. visą tekstą] / Breathing is related to many physiological systems, especially the cardiovascular system. Various breathing exercises are widely used both in sports and rehabilitation as a factor, acting on the body's functional status. It is therefore interesting and relevant to the scientific problem whether specific breathing exercises influence cardiovascular functional parameters and their changes during exercise. The object of investigation - cardiovascular functional state indicators and features of the breathing exercises. Aim: To identify the changing features in heart rate during breathing exercise that connects hyperventilation and respiratory detentions. Objectives: 1. To identify heart rate and the changing features of electrocardiogram intervals JT and RR ratio during active hyperventilation and breath holding. 2. To identify whether the cardiovascular functional state indicators changes in response to repeated hyperventilation and respiratory detentions. 3. To identify the fatigue influence on cardiovascular functional state indicators during breathing exercises that connects hyperventilation and breathing detentions. Hypothesis: We believe that specific breathing exercises have a positive effect on cardiovascular functional parameters and their changes during exercise. The methods: 1. Electrocardiography; 2. Arterial blood pressure measurement; 3. Exercise test. Organization of the research: The research was conducted in LSU kinesiology lab in 2012-2014. Participated eight... [to full text]

Les objectifs de cette thèse sont: i) de mettre au point de nouvelles techniques adaptées à la période néonatale d'analyse automatique des signaux physiologiques cardiaque (ECG) et respiratoire (RESP) afin d'étudier la variabilité de la fréquence cardiaque (VFC) et respiratoire (VFR), ainsi que les interrelations cardiorespiratoires; ii) de les valider et de les utiliser sur des modèles ovins pour mieux comprendre les altérations du contrôle cardiorespiratoire dans des différentes situations expérimentales. Durant les expérimentations, les agneaux étaient non sédationnés et libres de leurs mouvements, ce qui rend le traitement des signaux ECG et RESP enregistrés durant plusieurs heures difficile, à cause des artefacts. D'abord, une chaîne de traitement semi-automatique des signaux a été proposée. Elle comprend l'élimination automatique des périodes artefactuelles, l'extraction des séries temporelles des segments propres de l'ECG et du signal RESP, l'application d'un test de stationnarité sur ces séries temporelles pour extraire les segments stationnaires et le calcul de différents indices de la VFC et la VFR obtenus en appliquant des analyses linéaires et non linéaires. Ces analyses ont été complétées par la mesure des interrelations cardiorespiratoires. Cette chaîne de traitement a permis d'étudier les effets de trois situations expérimentales sur le contrôle cardiorespiratoire. La première situation cherche à étudier l'exposition d'agneaux nouveau-nés à la fumée de cigarette durant les deux premières semaines de vie. Une importante altération des interrelations cardiorespiratoires a été mise en évidence, surtout au niveau de l'arythmie sinusale respiratoire et du couplage cardioventilatoire. Ce résultat inédit donne un éclairage nouveau sur la physiopathologie des effets de l'exposition à la fumée de cigarette en période néonatale, incluant en particulier le syndrome de la mort subite du nourrisson. La deuxième situation expérimentale examine l'hyperbilirubinémie (HB) des agneaux prématurés. Une HB modérée a été induite durant 17h par injection intraveineuse de bilirubine. Les effets de l'HB modérée sur la VFC, la VFR et les interrelations cardiorespiratoires ont été évalués sur 7 heures d'enregistrement au moment de l'HB (J0) et 72h plus tard (J3), après normalisation de la bilirubinémie. À J0, une augmentation de la variabilité accompagnée d'une augmentation des indices fréquentiels de la VFC a été observée indiquant une coactivation sympathovagale. Tous ces effets ont disparu à J3. Une diminution de la fréquence respiratoire a été retrouvé avec une augmentation de la VFR; ces effets étaient maintenus jusqu'à J3. Une augmentation de l'arythmie sinusale respiratoire, de la synchronisation et du nombre de RR dans une inspiration et une expiration a été observée. Ces deux derniers effets étaient toujours présents au jour 3. La troisième situation expérimentale concerne l'application nasale d'une pression positive continue (PPC) de 6 cmH2O à des agneaux nouveau-nés sains pendant 6 heures. Une augmentation de la fréquence cardiaque a été observée avec diminution des indices temporels et fréquentiels de la VFC et augmentation de la complexité des intervalles RR. De plus, un ralentissement de la respiration a été montré avec allongement de la durée de l'expiration et diminution de la VFR indiquant une stabilisation de la respiration. Enfin, la seule altération des interrelations cardiorespiratoires retrouvée était une augmentation du nombre de RR dans le cycle respiratoire attribuable à l'augmentation de la fréquence cardiaque et à la diminution de la fréquence respiratoire. L'interprétation des résultats a été approfondie en utilisant une approche à base de modèles pour représenter le comportement des systèmes cardiovasculaire, respiratoire et du baroréflexe artériel dans les conditions expérimentales. Celle-ci permet d'accéder à des variables physiologiques difficilement observables durant les expérimentations. / The objectives of this thesis are: i) to develop new techniques, adapted to the neonatal period, for the automatic analysis of cardiac (ECG) and respiratory (RESP) signals in order to study heart rate variability (HRV), respiratory rate variability (RRV), as well as cardiorespiratory interrelations; ii) to validate these techniques and use them on neonatal ovine models to better understand alterations in the cardiorespiratory control in experimental situations mimicking exposure to postnatal environmental tobacco smoke, hyperbilirubinemia in the premature infant and continuous positive airway pressure application. In the different experimental situations, the lambs were without sedation and moving freely; this makes the treatment of ECG and RESP signals recorded for several hours difficult because of artifacts. As a first step, a semi-automated signal processing approach has been proposed. It includes the automatic elimination of artefactual periods, the extraction of time series from the clean segments of the ECG and RESP signals, the performance of a stationarity test in order to extract stationary segments, the application of linear (in time and frequency domains) and nonlinear HRV and RRV analysis as well as the calculation of cardiorespiratory interrelations indices. This approach was validated and allowed to study the effects of three different experimental conditions on cardiorespiratory control. The first condition explored the effects of exposing newborn lambs to postnatal environmental tobacco smoke (ETS) for the first two weeks of life. Significant impairment of cardiorespiratory interrelations was demonstrated, particularly for respiratory sinus arrhythmia and cardioventilatory coupling. This novel result sheds new light on the physiopathology of the effects of ETS exposure in the neonatal period, particularly for sudden infant death syndrome. The second experimental situation corresponds to hyperbilirubinemia (HB) of premature lambs. Moderate HB was induced for 17h by intravenous injection of bilirubin. The effects of moderate HB on HRV, RRV and cardiorespiratory interrelationships were assessed over 7 hours of recording during acute HB (D0) and after 72h (D3), following normalization of bilirubinemia. On D0, an increase in HRV accompanied by an increase in frequency indices of HRV was observed, indicating sympathovagal coactivation. These effects were absent on D3. A decreased respiratory rate and an increase in RRV were noted on D0; these effects were maintained until D3. The study of cardiorespiratory interrelations showed an increase in respiratory sinus arrhythmia, phase synchronization and the number of RRs in inspiration and expiration. The latter effects were still observed on day 3. The third experimental situation concerns the nasal application of a continuous positive pressure (CPAP) of 6 cmH2O in healthy neonatal lambs for 6 hours. An increase in heart rate associated with a decrease in temporal and frequency indices of HRV and an increase in RR interval complexity was observed. In addition, we observed a decrease in respiratory rate accompanied by a prolonged expiration and a decreased RRV, indicating a stabilization of breathing. Finally, no alterations of cardiorespiratory interrelations were observed excepted an increase in the number of RRs in the respiratory cycle explained by the increased heart rate and decreased respiratory rate. To further understand these results, a model of cardiorespiratory coupling comprising three compartments mimicking the functioning of the cardiovascular and respiratory systems and the arterial baroreflex, was adapted to the conditions of the experiment. Results obtained with the model allowed to gain access to variables that were not measured during the experiments.