Ganglionated plexuses (GPs) are major constituents of the intrinsic cardiac nervous system, the final common integrator of regional cardiac control. We hypothesized that nicotinic stimulation of individual GPs exerts divergent regional influences, affecting atrial as well as ventricular functions. In 22 anesthetized canines, unipolar electrograms were recorded from 127 atrial and 127 ventricular epicardial loci during nicotine injection (100 mcg in 0.1 ml) into either the 1) right atrial (RA), 2) dorsal atrial, 3) left atrial, 4) inferior vena cava-inferior left atrial, 5) right ventricular, 6) ventral septal ventricular or 7) cranial medial ventricular (CMV) GP. In addition to sinus and AV nodal function, neural effects on atrial and ventricular repolarization were identified as changes in the area subtended by unipolar recordings under basal conditions and at maximum neurally-induced effects. Animals were studied with intact AV node or following ablation to achieve ventricular rate control. Atrial rate was affected in response to stimulation of all 7 GPs with an incidence of 50-95% of the animals among the different GPs. AV conduction was affected following stimulation of 6/7 GP with an incidence of 22-75% among GPs. Atrial and ventricular repolarization properties were affected by atrial as well as ventricular GP stimulation. Distinct regional patterns of repolarization changes were identified in response to stimulation of individual GPs. RAGP predominantly affected the RA and posterior right ventricular walls whereas CMVGP elicited biatrial and biventricular repolarization changes. Spatially divergent and overlapping cardiac regions are affected in response to nicotinic stimulation of neurons in individual GPs.

Cat hair receptors were studied to determine whether they could be distinguished by the following receptive field characteristics: thickness of innervated guard hairs, distance between innervated follicles and receptive field size. Initially the receptors were classified as G1, GI, G2 or D on the basis of their velocity requirements for excitation, their degree of linear directionality, their vibrational sensitivity, and whether they were activated by movement of down hairs. It was found that the thickest guard hairs on the posterior aspect of a cat's hindleg were usually 4-5 times thicker than the thinnest guard hairs from the same area and that G1, GI and G2 neurons innervated the full range of guard hair thicknesses available. Although there was a tendency for thicker guard hairs to be more heavily innervated, none of the neurons studied innervated thick guard hairs exclusively. While movement of the down hair and most guard hairs within D-mechanoreceptive fields easily evoked activity, a few guard hairs were regularly found for which mechanical displacement did not elicit a discharge even though they were well within the receptive field. Receptive field sizes and nearest neighbor distances between innervated follicles were smaller for D than for G1, GI and G2 receptors and greater for G1 than GI and G2 receptors.

Spinal ligaments may be a significant source of chronic back pain, yet they are often disregarded by the clinical community due to a lack of information with regards to their material response, and innervation characteristics. The purpose of this dissertation was to characterize the material response of spinal ligaments and to review their innervation characteristics. Review of relevant literature revealed that all of the major spinal ligaments are innervated. They cause painful sensations when irritated and provide reflexive control of the deep spinal musculature. As such, including the neurologic implications of iatrogenic ligament damage in the evaluation of surgical procedures aimed at relieving back pain will likely result in more effective long-term solutions. The material response of spinal ligaments has not previously been fully quantified due to limitations associated with standard soft tissue testing techniques. The present work presents and validates a novel testing methodology capable of overcoming these limitations. In particular, the anisotropic, inhomogeneous material constitutive properties of the human supraspinous ligament are quantified and methods for determining the response of the other spinal ligaments are presented. In addition, a method for determining the anisotropic, inhomogeneous pre-strain distribution of the spinal ligaments is presented. The multi-axial pre-strain distributions of the human anterior longitudinal ligament, ligamentum flavum and supraspinous ligament were determined using this methodology. Results from this work clearly demonstrate that spinal ligaments are not uniaxial structures, and that finite element models which account for pre-strain and incorporate ligament’s complex material properties may provide increased fidelity to the in vivo condition.

The sympathetic (SNS) and parasympathetic (PSNS) branches of the autonomic nervous system (ANS) innervate the heart, exerting excitatory and inhibitory influences (respectively) over cardiac functions (heart rate, AV conduction velocity, and contractility). However, the distribution and structure of SNS and PSNS innervation has not yet been well studied. Detailed characterization of the distributional organization and structural morphology of the SNS and PSNS in normal states is essential to the study of pathological autonomic remodeling. The present study utilized double immunohistochemical labeling techniques to examine tyrosine hydroxylase (TH) immunoreactive (IR) SNS and vesicular acetylcholine transporter (VAChT) IR PSNS axons and terminal structures in whole-mount atria of C57BL/6 mice. We found that: (1) The atria contain a dense network of ANS axons. TH-IR, VAChT-IR, and dual cholinergic/dopaminergic TH+VAChT-IR axons travel together in bundles on the epicardium before branching into differentiated terminal structures. (2) Parallel TH-IR and VAChT-IR axons often diverge from epicardial bundles and travel in parallel (less than 1μm apart) before forming terminal structures in the epicardium and myocardium. Such parallel SNS/PSNS axons interdigitize and have large alternating varicosities along their length adjacent to one other, suggesting possible antagonistic communication between both branches of the ANS at the prejunctional level. (3) Intrinsic cardiac ganglia (ICG) are targets for extrinsic sympathetic nerves which travel through ICG without forming large synaptic varicosities around cardiac principal neurons (PNs). (4) Small intensely fluorescent (SIF) cells (presumably chemoreceptors and/or interneurons) exist near SNS bundles, inside ICG, and in the epicardium unaccompanied by ganglia and nerve bundles. (5) The subpopulation of TH+VAChT-IR PNs within ICG form loose terminals in the atria and do not project to other PNs. (6) Both TH-IR and VAChT-IR axons innervate atrial vasculature. (7) TH-IR axons innervate fat pads adjacent to the heart. (8) SNS/PSNS parallelism is not exclusive to the atria. Similar structures exist in the esophagus, right ventricle, and small intestine. This study provides a novel and overall view of the innervation and interaction of the SNS and PSNS in the atria. This will underlie a foundation for future physiological, pharmacological, and anatomical studies of SNS/PSNS innervation, interaction, and remodeling in pathological states (such as aging, intermittent hypoxia and diabetes).

The purpose of this literature review was to identify any adaptations that could be made to the rehabilitation process for Traumatic Transfemoral Amputees. Traumatic Transfemoral Amputation is particularly debilitating with the amputees encountering many obstacles throughout the rehabilitation process. These obstacles can prevent the return to pre-morbid functioning. With an ever-increasing number of amputees within the United States, it is imperative the rehabilitation process be addressed. This literature review addresses possible adjustments in the initial stages of rehabilitation examining the post-operative, pre-prosthetic, and prosthetic rehabilitation stage to enhance the physical functioning for the amputee. This comprehensive literature review encompassing 63 academic and medical journals analyzes the research literature regarding each of the three stages of the post-operative procedure. The literature review synthesizes the research findings to see how procedures may be adapted to reduce the risk of further co-morbidities such as loss of bone mineral density and disuse atrophy. Loss of bone mineral density and disuse atrophy are the major contributing factors to the amputees decreased mobility. Reducing this loss can be addressed within the initial post-operative, pre-prosthetic, and prosthetic rehabilitation stages. Further research is required to examine the efficacy of these alterations in relation to this specific population.

The purpose of this study was to use retrograde tracing techniques to examine hepatic neuroanatomy in the rat model, with special emphasis upon the identification of previously undiscovered intrahepatic parasympathetic ganglia. Retrograde analysis was performed using Fluoro-Gold (FG) tracer injections of both male and female Sprague-Dawley rats. To accurately examine the neural connectivity of both the vasculature and the parenchyma, the FG-labelled livers were divided into two groups. In the first, vessel trees were extracted via dissection and whole-mounted for bright field and confocal visualization. Left lateral lobes taken from the male and female liver that constituted the second group were sectioned, and slices from various layers of tissue were fixed to slides and visualized. The results indicated the presence of several large, fluorescent structures bearing a strong resemblance to parasympathetic ganglia. However, the images were not detailed enough to properly differentiate true ganglia from similar paraganglia. Regardless, the importance of this experiment lies in its attempt to revisit an understudied field in neuroscience, and the findings of this study could potentially provide a starting point for further inquiry.

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No description available.

Behavioral and physiological reactivity, and its relationship to cardiovascular disease has been studied in men for a number of years, and the expression of anger has been identified as a possible contributing factor. Few studies, however, have focused specifically on the reactivity of women, and those which have suggest that women are less reactive to laboratory tasks than men. For the present study, 45 undergraduate women, ages 19-21 were selected from a larger sample of 135 women to represent three discrete groups: (1) low anger/low denial, (2) high anger/low denial, and (3) low anger/high denial, based on their scores on the State-Trait Anger Expression Inventory, P and the Marlowe-Crowne Social Desirability Scale. It was hypothesized that the three groups would show reliable differences in heart rate and blood pressure during presentation of a stressful laboratory stimulus, the Stroop Color and Word Test. Each subject received three counterbalanced conditions: (1) no feedback, (2) error feedback without observer present, (3) error feedback with observer present. As hypothesized, women who reported a high level of denial and a low level of anger exhibited reliably greater systolic blood pressure to the no-feedback condition than subjects who reported low levels of denial and anger. The hypothesis that all groups would display greater A reactivity in a condition which provided error feedback with observation was not supported. / Master of Science

Ces dernières années, un nouveau composant de l'environnement des tumeurs (ET) a été mis en évidence: les projections des neurones du système nerveux. En effet, les tumeurs sont infiltrées par des axones, ce qui pourrait réguler la progression du cancer.Le cancer du pancréas fait partie des cancers les plus mortels. Les traitements thérapeutiques actuels qui ciblent ce cancer ne sont pas efficaces. Il est donc important de mieux comprendre les différentes composantes de l'ET de ce cancer afin d’identifier de nouvelles cibles thérapeutiques. Nous proposons de décrire l’innervation des tumeurs pancréatiques ce qui est le point de départ pour mieux comprendre l’importance de cette composante de l'ET. Les objectifs ont été d’analyser en 3D les réseaux d'axones qui innervent le pancréas sain et cancéreux, ainsi que leurs relations avec d'autres types cellulaires de l'ET (vaisseaux sanguins (VS)).Pour cela, nous avons utilisé une méthode d'imagerie 3D de pancréas entiers, rendus transparents, qui proviennent de modèles génétiques de souris qui développent des cancers du pancréas similaires à ceux de l'homme. Nous avons observé que les réseaux d'axones sont plus denses et plus complexes dans les régions cancéreuses du pancréas par rapport aux régions saines. Alors que dans les tissus sains les axones sont associés aux VS, ils ne le sont plus dans les régions cancéreuses. Nous avons de plus identifié des groupes morphologiques de réseaux d'axones qui permettent de discriminer une région saine d'une région cancéreuse.L’analyse de la structure en 3D de ces réseaux d'axones pourrait donc représenter une donnée prédictive et pronostique de l'état d'avancé clinique de la maladie. / Cancers are diseases in which cancer cells interact with a complex tumor environment (TE). In recent years, a new component of TE has been highlighted: neuronal projections of the nervous system. Indeed, the axons of neurons innervate the tumors, which could regulate cancer progression.Pancreatic cancer is among the most deadly cancers. Indeed, the current therapeutic treatments that target this cancer are not effective. It is therefore important to better understand the different components of the TE of this cancer in order to identify new potential therapeutic targets.In this thesis, we propose to describe the innervation of pancreatic tumors which is the starting point to better understand the importance of this component of the TE. The objectives were to visualize and analyze in 3D the networks of axons that innervate the healthy and cancerous pancreas, as well as their relations with other cell types of the TE (blood vessels (BV)).For this, we used a method of 3D imaging of whole pancreas, made transparent, which come from genetic models of mice that develop pancreatic cancer similar to that of humans.We observed that axon networks are denser and more complex in cancerous regions of the pancreas compared to healthy regions. Moreover, while in healthy tissue, axons are associated with BV, they are no longer in cancerous areas.We also identified morphological groups of axon networks that discriminate a healthy region from a cancerous region.The analysis of the 3D structure of these axon networks could thus represent a predictive and prognostic value for the progression of the disease.