Previous studies have shown that microinjection of atrial natriuretic peptide into the caudal nucleus tractus solitarii produces significant increases in local neuronal firing rate associated with reductions in arterial pressure in anesthetized Wistar rats. Single units excited by microinjection of atrial natriuretic peptide into the caudal nucleus tractus solitarii were also excited by activat...

The neuropeptide substance P (SP) is found in vagal afferent nerves within the nucleus tractus solitarii, where it is released on stimulation of arterial baroreflexes. The neurokinin-1 receptors at which SP may act have been identified in the nucleus tractus solitarii, but there remains uncertainty if the neurons at which SP acts are critical to baroreflex transmission. By using SP conjugated w...

it has been shown that nitric oxide is synthesized in the central nervous system as well as in vascular endothelial cells. recently, it was reported that nitric oxide was involved in central cardiovascular regulation, baroreflex modulation, and involved in a reciprocal release with excitatory amino acids in the nucleus tractus solitarii of rats. the purpose of the present study was to investiga...

It has been shown that nitric oxide is synthesized in the central nervous system as well as in vascular endothelial cells. Recently, it was reported that nitric oxide was involved in central cardiovascular regulation, baroreflex modulation, and involved in a reciprocal release with excitatory amino acids in the nucleus tractus solitarii of rats. The purpose of the present study was to investiga...

We evaluated the modulatory action of angiotensin II at the nucleus tractus solitarii on spontaneous baroreceptor reflex response, the angiotensin subtype receptors involved, and the role of Fos protein in this process, using Sprague-Dawley rats anesthetized with pentobarbital sodium. Microinjection bilaterally of angiotensin (Ang ) II (5, 10, 20, or 40 pmol) into the nucleus tractus solitarii ...

Vagal afferents signal gastric acid challenge to the nucleus tractus solitarii of the rat brainstem. This study investigated whether nucleus tractus solitarii neurons in the mouse also respond to gastric acid challenge and whether this chemonociceptive input is modified by neuropeptide Y acting via neuropeptide Y receptors of type Y2 or Y4. The gastric mucosa of female mice was exposed to diffe...

Animal studies have shown the importance of the nucleus tractus solitarii, a collection of neurons in the brain stem, in the acute regulation of blood pressure. Impulses arising from the carotid and aortic baroreceptors converge in this center, where the first synapse of the baroreflex is located. Stimulation of the nucleus tractus solitarii provides an inhibitory signal to other brain stem str...

We have previously shown that microinjection of monoclonal antibody to atrial natriuretic peptide (ANP) into the caudal nucleus tractus solitarii causes a pressor response in salt-sensitive spontaneously hypertensive rats (SHR) fed a basal (1%) salt diet, suggesting that endogenous ANP in this region may be involved in the centrally mediated regulation of blood pressure in this model. The prese...

The purpose of this study was to assess the chronic effects of lesions of the nucleus tractus solitarii on the cardiovascular activity of rats. Arterial pressure and heart rate were recorded in conscious, unrestrained rats 7-216 days following placement of electrolytic lesions in the nucleus tractus solitarii. To assess the impact of environmental stimuli on the mean level and lability of the m...

We compared the mean arterial pressure and heart rate activity of conscious, unrestrained rats during 1-hour and 24-hour continuous recording sessions, 3 to 4 weeks after either sinoartic denervation, placement of electrolytic lesions in the nucleus tractus solitarii, or sham operations. Sinoaortic denervation and nucleus tractus solitarii lesions both eliminated the reflex bradycardia to a phe...