Related Experiment Video
Updated: May 19, 2026
Preparation of Acute Brain Slices Using an Optimized N-Methyl-D-glucamine Protective Recovery Method
Published on: February 26, 2018
Peripheral chemoreceptors mediate training-induced plasticity in paraventricular nucleus pre-autonomic oxytocinergic
Josiane C Cruz1, Marina T Cavalleri, Alexandre Ceroni
1Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of S˜ao Paulo, 05508-000 São Paulo, Brazil.
Abstract:
We showed previously that sino-aortic denervation prevented training-induced plasticity in pre-autonomic oxytocinergic neurons and blocked the beneficial effects of training. In this study, we investigate the combined effect of training and removal of specific chemoreceptor afferents on both cardiovascular parameters and oxytocin (OT) gene and protein expression within the hypothalamic paraventricular nucleus (PVN). Wistar rats and spontaneously hypertensive rats (SHRs) underwent carotid body denervation or sham surgery and were trained or kept sedentary for 3 months. After haemodynamic measurements at rest, rats were anaesthetized for brain perfusion. Fresh (perfused with PBS) and fixed brains (perfused with 4% paraformaldehyde) were processed for PVN OT mRNA (real-time PCR) and OT immunoreactivity within PVN subnuclei. In sham-operated rats, training improved treadmill performance and reduced resting heart rate (Wistar, -8%; SHRs, -10%), with a reduction in blood pressure only in SHRs (-8%). Training was accompanied by increased PVN OT mRNA expression (twofold increase in sham-operated SHRs) and peptide density in the posterior, ventromedial and dorsal cap PVN subnuclei (on average 70% increase in both strains), with significant correlations between OT content and training-induced resting bradycardia in sham-operated groups. Carotid body denervation did not interfere with the performance gain, abolished chemoreflex activation (without changing baroreflex control) and blocked training-induced cardiovascular adaptations and training-induced changes in PVN OT content in both strains. After carotid body denervation, there was no correlation between OT mRNA or OT immunoractivity and resting heart rate. The chronic absence of chemoreceptor inputs uncovers an unknown role of chemoreceptor signalling in driving the plasticity/activity of PVN oxytocinergic pre-autonomic neurons, thus mediating training-induced cardiovascular adaptive responses.
Related Concept Videos
01:31Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated. Under...
01:22Physiology of Respiration II: Neurogenic Control of Respiration
Central Control
The brainstem is the primary site of central control, hosting respiratory centers:
01:18Neural Regulation of Blood Pressure
Baroreceptor Reflex
Baroreceptors, located in the carotid sinuses and aortic arch, detect changes in blood pressure. When blood pressure rises, these stretch-sensitive receptors...
01:23Physiological Control of Respiration
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
01:27Regulation of the Cardiovascular System
The regulation of the cardiovascular system involves the autonomic nervous system (ANS), baroreceptors, and chemoreceptors, ensuring that heart rate and blood pressure are appropriately modulated in response to varying physiological demands.
The ANS comprises two main divisions: the sympathetic and parasympathetic nervous systems. The sympathetic nervous system enhances...
01:18Neural Control of Respiration
Respiratory Centers in the Brainstem
Two primary areas comprise the respiratory center: the medullary respiratory center in the medulla oblongata and the pontine respiratory group in the pons. The...