Angiotensinergic innervation of rat and human mesenteric resistant blood vessels

In contrast to the current believe that angiotensin II (Ang II) only interacts with the sympathetic nervous system (SNS) as a circulating hormone, we document here the existence of an endogenous renin-angiotensin system (RAS) in the sympathetic coeliac ganglion and the angiotensinergic innervation with mesenteric resistant blood vessels. Our findings indicate that Ang II is synthesized inside the neurons of sympathetic coeliac ganglion and may act as an endogenous neurotransmitter locally on the mesenteric resistant blood vessels

Differences in sympathetic nervous response due to gender

Thesis (M.A.)--Boston UniversityThe sympathetic nervous system, in addition to its many roles as part of the autonomic nervous system, utilizes contact with many organs in the body to recruit them for an immediate response to danger. The multiple survival responses that the sympathetic nervous system manifests are typically known as the fight, flight or freeze response. The freeze response, otherwise referred to as tonic immobility, is being explored here for its survival value in the specific context of gender. It is our belief that in situations of interpersonal aggression, females may be more suited to survive by utilizing a tonic response when they are confronted with violence. Research in the areas of both tonic immobility and gender differences will be explored and compared, as well as animal origins of tonic immobility. It is our hope that by looking at the various studies already conducted on these topics, a path for future research on gender and sympathetic response may be illuminated in the field of physiological psychology

Macaque cardiac physiology is sensitive to the valence of passively viewed sensory stimuli.

Autonomic nervous system activity is an important component of affective experience. We demonstrate in the rhesus monkey that both the sympathetic and parasympathetic branches of the autonomic nervous system respond differentially to the affective valence of passively viewed video stimuli. We recorded cardiac impedance and an electrocardiogram while adult macaques watched a series of 300 30-second videos that varied in their affective content. We found that sympathetic activity (as measured by cardiac pre-ejection period) increased and parasympathetic activity (as measured by respiratory sinus arrhythmia) decreased as video content changes from positive to negative. These findings parallel the relationship between autonomic nervous system responsivity and valence of stimuli in humans. Given the relationship between human cardiac physiology and affective processing, these findings suggest that macaque cardiac physiology may be an index of affect in nonverbal animals

Alterations in electrodermal activity and cardiac parasympathetic tone during hypnosis

Exploring autonomic nervous system (ANS) changes during hypnosis is critical for understanding the nature and extent of the hypnotic phenomenon and for identifying the mechanisms underlying the effects of hypnosis in different medical conditions. To assess ANS changes during hypnosis, electrodermal activity and pulse rate variability (PRV) were measured in 121 young adults. Participants either received hypnotic induction (hypnosis condition) or listened to music (control condition), and both groups were exposed to test suggestions. Blocks of silence and experimental sound stimuli were presented at baseline, after induction, and after de-induction. Skin conductance level (SCL) and high frequency (HF) power of PRV measured at each phase were compared between groups. Hypnosis decreased SCL compared to the control condition; however, there were no group differences in HF power. Furthermore, hypnotic suggestibility did not moderate ANS changes in the hypnosis group. These findings indicate that hypnosis reduces tonic sympathetic nervous system activity, which might explain why hypnosis is effective in the treatment of disorders with strong sympathetic nervous system involvement, such as rheumatoid arthritis, hot flashes, hypertension, and chronic pain. Further studies with different control conditions are required to examine the specificity of the sympathetic effects of hypnosis

Neuraxial modulation for treatment of VT storm.

In the hyperadrenergic state of VT storm where shocks are psychologically and physiologically traumatizing, suppression of sympathetic outflow from the organ level of the heart up to higher braincenters plays a significant role in reducing the propensity for VT recurrence. The autonomic nervous system continuously receives input from the heart (afferent signaling), integrates them, and sends efferent signals to modify or maintain cardiac function and arrhythmogenesis. Spinal anesthesia with thoracic epidural infusion of bupivicaine and surgical removal of the sympathetic chain including the stellate ganglion has been shown to decrease recurrences of VT. Excess sympathetic outflow with catecholamine release can be modified with catheter-based renal denervation. The insights provided from animal experiments and in patients that are refractory to conventional therapy have significantly improved our working understanding of the heart as an end organ in the autonomic nervous system

Variability of the Heart Rhythm as an Additional Marker for Determining Vegetative Functions in Patients with Chronic Cerebral Ischemia

Aim. Practical cardiology is in constant search for non-invasive vascular risk markers. Heart rhythm reflects the body\u27s response to various stimuli of the external and internal environment. Heart rate variability (HRV) has a prognostic and diagnostic value and allows timely identification of conditions that threaten life. The results of an instrumental examination of heart rhythm fluctuations in patients suffering from chronic cerebral ischemia against the background of angina pectoris of different functional classes allows to evaluate the prognosis of the disease and select the appropriate treatment.Materials and methods. An assessment of the state of the mechanisms of regulation of physiological functions in patients suffering from chronic cerebral ischemia against the background of angina pectoris of different functional classes was obtained according to spectral and temporal analysis of heart rate variability using electrocardiographic monitoring. The spectral characteristics of the heart rate variability were studied: HF (high frequency), LF (low frequency), VLF (very low frequency).Results. Heart rhythm regulation in patients with chronic cerebral ischemia occurred under the influence of neurohumoral mechanisms. The imbalance of functional systems was caused by changes in the autonomic nervous system, which disrupted the normal functioning of the sympathetic and parasympathetic parts. We marked decrease in the activity of the parasympathetic autonomic nervous system, which changed the indices of spectral analysis, while the high-frequency component of the spectrum was characterized by a decrease, while the low-frequency component was characterized by an increase. The progression of stable angina of tension (SAT) in patients with chronic cerebral ischemia (CCI) occurred with disruption of the autonomic nervous system (ANS) and was associated with a shift in the physiological response towards sympathetic activity. This was particularly pronounced in patients in group 2 with CCI on the background of SAT III FC, as the regulatory mechanisms were in a critical state of tension against the background of long-term chronic ischemia, they showed a high level of humoral modulation of regulatory mechanisms, which was manifested by excessive VLF and high-frequency oscillations.Conclusions. A connection was established between the autonomic nervous system and chronic cerebral ischemia, which was expressed in the imbalance of the ANS, associated with reliable signs of the dominant sympathetic system, which was associated with the progression of stable angina of tension

Physiologic regulation of heart rate and blood pressure involves connexin 36-containing gap junctions

Chronically elevated sympathetic nervous activity underlies many cardiovascular diseases. Elucidating the mechanisms contributing to sympathetic nervous system output may reveal new avenues of treatment. The contribution of the gap junctional protein connexin 36 (Cx36) to the regulation of sympathetic activity and thus blood pressure and heart rate was determined, using a mouse with specific genetic deletion of Cx36. Ablation of the Cx36 protein was confirmed in sympathetic preganglionic neurons of Cx36 knockout (KO) mice. Telemetric analysis from conscious Cx36 KO mice revealed higher variance in heart rate and blood pressure during rest and activity compared to wildtype (WT) mice, and smaller responses to chemoreceptor activation when anesthetized. In the working heart brainstem preparation of the Cx36 KO mouse, respiratory-coupled sympathetic nerve discharge was attenuated and responses to chemoreceptor stimulation and noxious stimulation were blunted compared to WT mice. Using whole cell patch recordings, sympathetic preganglionic neurons in spinal cord slices of Cx36 KO mice displayed lower levels of spikelet activity compared to WT mice, indicating reduced gap junction coupling between neurons. Cx36 deletion therefore disrupts normal regulation of sympathetic outflow with effects on cardiovascular parameters

TSE pathogenesis in cattle and sheep

Many studies have been undertaken in rodents to study the pathogenesis of transmissible spongiform encephalopathies (TSE). Only a few studies have focused on the pathogenesis of bovine spongiform encephalopathy (BSE) and scrapie in their natural hosts. In this review, we summarize the most recent insights into the pathogenesis of BSE and scrapie starting from the initial uptake of TSE agents and crossing of the gut epithelium. Following replication in the gut-associated lymphoid tissues (GALT), TSE agents spread to the enteric nervous system (ENS) of the gut. Infection is then carried through the efferent fibers of the post-ganglionic neurons of the parasympathetic and sympathetic nervous system to the pre-ganglionic neurons in the medulla oblongata of the brain and the thoracic segments of the spinal cord. The differences between the pathogenesis of BSE in cattle and scrapie in sheep are discussed as well as the possible existence of additional pathogenetic routes

Self-Regulation of Breathing as a Primary Treatment for Anxiety

Understanding the autonomic nervous system and homeostatic changes associated with emotions remains a major challenge for neuroscientists and a fundamental prerequisite to treat anxiety, stress, and emotional disorders. Based on recent publications, the inter-relationship between respiration and emotions and the influence of respiration on autonomic changes, and subsequent widespread membrane potential changes resulting from changes in homeostasis are discussed. We hypothesize that reversing homeostatic alterations with meditation and breathing techniques rather than targeting neurotransmitters with medication may be a superior method to address the whole body changes that occur in stress, anxiety, and depression. Detrimental effects of stress, negative emotions, and sympathetic dominance of the autonomic nervous system have been shown to be counteracted by different forms of meditation, relaxation, and breathing techniques. We propose that these breathing techniques could be used as firstline and supplemental treatments for stress, anxiety, depression, and some emotional disorders