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Autonomic Innervation (autonomic + innervation)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Effects of Direct Sympathetic and Vagus Nerve Stimulation on the Physiology of the Whole Heart , A Novel Model of Isolated Langendorff Perfused Rabbit Heart with Intact Dual Autonomic Innervation

EXPERIMENTAL PHYSIOLOGY, Issue 3 2001
G. André Ng
A novel isolated Langendorff perfused rabbit heart preparation with intact dual autonomic innervation is described. This preparation allows the study of the effects of direct sympathetic and vagus nerve stimulation on the physiology of the whole heart. These hearts (n= 10) had baseline heart rates of 146 ± 2 beats min,1 which could be increased to 240 ±11 beats min,1 by sympathetic stimulation (15 Hz) and decreased to 74 ± 11 beats min,1 by stimulation of the vagus nerve (right vagus, 7 Hz). This model has the advantage of isolated preparations, with the absence of influence from circulating hormones and haemodynamic reflexes, and also that of in vivo preparations where direct nerve stimulation is possible without the need to use pharmacological agents. Data are presented characterising the preparation with respect to the effects of autonomic nerve stimulation on intrinsic heart rate and atrioventricular conduction at different stimulation frequencies. We show that stimulation of the right and left vagus nerve have differential effects on heart rate and atrioventricular conduction. [source]

Amitriptyline modifies the visceral hypersensitivity response to acute stress in the irritable bowel syndrome

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 5 2009
N. M. THOUA
Summary Background, Acute physical stress causes alteration in gut autonomic function and visceral hypersensitivity in patients with irritable bowel syndrome (IBS). We have developed a model to measure this stress response. Aim, To assess whether treatment with a drug effective in treating IBS (amitriptyline) alters the response to acute stress in IBS patients. Methods, Nineteen patients with IBS were given amitriptyline 25,50 mg. Patients underwent physical stress (cold pressor) test at baseline and after 3 months of treatment. Physiological parameters measured were: stress perception; systemic autonomic tone [heart rate (HR) and blood pressure (BP)]; gut specific autonomic innervation [rectal mucosal blood flow (RMBF)] and visceral sensitivity (rectal electrosensitivity). Results, Fourteen of 19 (74%) patients improved symptomatically after 3 months of amitriptyline. Acute stress induced increased perception of stress and systemic autonomic tone and reduced RMBF in symptomatic responders and nonresponders (P > 0.05 for all). All nonresponders but only 3 of 14 responders continued to exhibit stress-induced reduced pain threshold at 3 months (change from baseline ,31% vs. +2%, P < 0.03 respectively). Conclusion, In this open study, amitriptyline appears to decrease stress-induced electrical hypersensitivity; this effect is independent of autonomic tone. The gut response to acute stress deserves further study as a model to study drug efficacy in IBS. [source]

Are dysautonomic and sensory symptoms present in early Parkinson's disease?

ACTA NEUROLOGICA SCANDINAVICA, Issue 2010
O.-B. Tysnes
Tysnes O-B, Müller B, Larsen JP. Are dysautonomic and sensory symptoms present in early Parkinson's disease? Acta Neurol Scand: 2010: 122 (Suppl. 190): 72,77. © 2010 John Wiley & Sons A/S. Parkinson's disease (PD) occurs with an annual incidence of 13/100.000, is slightly more frequent in men and is characterized by the motor symptoms tremor, rigidity, bradykinesia and postural instability. In addition, non-motor symptoms have been increasingly connected to the disease although already described in James Parkinson's ,Essay on the shaking palsy' from 1817. The motor symptoms in PD are related to the degeneration of dopaminergic cells in the substantia nigra (SN). These symptoms respond well to dopaminergic substitution. It is much more unclear whether non-motor symptoms like dysautonomia, insomnia, day-time sleepiness, fatigue, pain and neuropsychiatric symptoms respond to levodopa. Autonomic symptoms include dizziness because of orthostatic hypotension, constipation, nausea, voiding symptoms and increased sweating. Such symptoms as well as sensory symptoms like hyposmia and pain are very frequently reported in PD and seem to occur early in the disease process. Braak proposed a sequential model of neuropathology in PD starting with affection of the olfactory bulb and the autonomic innervation of the heart and gut. Affection of SN is seen from Braak stage 3, and limbic and cortical structures are affected in the later stages of the disease. Currently, the evidence for sensory and autonomic involvement in PD is reviewed with special focus on the early phase of the disease. [source]