scholarly journals Neurones in the brain stem of the cat excited by vagal afferent fibres from the heart and lungs.

1985 ◽  
Vol 369 (1) ◽  
pp. 1-15 ◽  
Author(s):  
J A Bennett ◽  
C S Goodchild ◽  
C Kidd ◽  
P N McWilliam
Keyword(s):  
Brain Stem ◽  
Vagal Afferent ◽  
The Brain

Vagal interactions on brain stem neurons receiving input from the proximal stomach in cats

1990 ◽  
Vol 258 (2) ◽  
pp. G320-G327 ◽  
Author(s):  
William D. Barber ◽  
Chun-Su Yuan ◽  
Brian J. Cammarata
Keyword(s):  
Brain Stem ◽  
Nucleus Tractus Solitarius ◽  
Recording Site ◽  
Proximal Stomach ◽  
Neuronal Interactions ◽  
Afferent Fibers ◽  
Significant Difference ◽  
The Mean ◽  
Vagal Afferent ◽  
The Brain

Gastric vagal fibers on the proximal stomach that join the dorsal and ventral vagal trunks were electrically stimulated to localize and evaluate brain stem neuronal interactions in anesthetized cats. The brain stem responses were located in nucleus tractus solitarius in the dorsomedial, caudal region of the medulla oblongata. There was no significant difference in the mean latency of the gastric vagally evoked brain stem response between the dorsal and ventral vagal trunks. The responses consisted of single or multiple spikes with a mean latency of ap290 ± 50 (SD) ms. Forty-one percent, or 168 unitary responses of the 406 total responses recorded, showed convergence of proximal gastric vagal input from both the dorsal and ventral vagal trunks on the same recording site or on the same cell. Of those unitary responses that received convergent proximal gastric vagal input, 95 unitary responses (57%) showed convergence of input to the same area, on different cells at the same recording site during a single trial. Seventy-three single units (43%) received convergent input from proximal gastric vagal afferent fibers in both the dorsal and ventral trunks. Fifty-two, or 7l%, of the single unit convergent responses were excitatory in nature, whereas the remaining 29% were inhibitory. These data demonstrated that proximal gastric vagal afferent fibers that join the dorsal and ventral trunks converged on a significant number of single neurons in the brain stem. The convergent response was synaptically secure and exerted an identifiable biasing effect on the response of the brain stem neuron. These convergent interactions may play an important role in reflex mechanisms concerned with adaptive relaxation to accommodate the ingested content by the proximal stomach. gastric; proximal gastric vagal; ventral vagus; dorsal vagus; nucleus tractus solitarius; vagal brain stem interactions Submitted on March 14, 1988 Accepted on September 19, 1989

scholarly journals Effects of cholecystokinin-8s in the nucleus tractus solitarius of vagally deafferented rats

2007 ◽  
Vol 292 (3) ◽  
pp. R1092-R1100 ◽  
Author(s):  
V. Baptista ◽  
K. N. Browning ◽  
R. A. Travagli
Keyword(s):  
Brain Stem ◽  
Nucleus Tractus Solitarius ◽  
Glutamate Release ◽  
Intraperitoneal Administration ◽  
Whole Cell Patch Clamp ◽  
Afferent Fibers ◽  
Vagal Afferent ◽  
Sites Of Action ◽  
The Brain ◽  
Brain Stem Slices

We have shown recently that cholecystokinin octapeptide (CCK-8s) increases glutamate release from nerve terminals onto neurons of the nucleus tractus solitarius pars centralis (cNTS). The effects of CCK on gastrointestinal-related functions have, however, been attributed almost exclusively to its paracrine action on vagal afferent fibers. Because it has been reported that systemic or perivagal capsaicin pretreatment abolishes the effects of CCK, the aim of the present work was to investigate the response of cNTS neurons to CCK-8s in vagally deafferented rats. In surgically deafferented rats, intraperitoneal administration of 1 or 3 μg/kg CCK-8s increased c-Fos expression in cNTS neurons (139 and 251% of control, respectively), suggesting that CCK-8s' effects are partially independent of vagal afferent fibers. Using whole cell patch-clamp techniques in thin brain stem slices, we observed that CCK-8s increased the frequency of spontaneous and miniature excitatory postsynaptic currents in 43% of the cNTS neurons via a presynaptic mechanism. In slices from deafferented rats, the percentage of cNTS neurons receiving glutamatergic inputs responding to CCK-8s decreased by ∼50%, further suggesting that central terminals of vagal afferent fibers are not the sole site for the action of CCK-8s in the brain stem. Taken together, our data suggest that the sites of action of CCK-8s include the brain stem, and in cNTS, the actions of CCK-8s are not restricted to vagal central terminals but that nonvagal synapses are also involved.

Permeability of the microcirculation in area postrema of rat

1988 ◽  
Vol 46 ◽  
pp. 348-349
Author(s):  
Shams M. Ghoneim ◽  
Frank M. Faraci ◽  
Gary L. Baumbach
Keyword(s):  
Brain Stem ◽  
Area Postrema ◽  
Upper Body ◽  
Sprague Dawley ◽  
Sodium Cacodylate ◽  
Acute Hypertension ◽  
Sprague Dawley Rats ◽  
Ultrastructural Characteristics ◽  
The Brain ◽  
Adjacent Brain

The area postrema is a circumventricular organ in the brain stem and is one of the regions in the brain that lacks a fully functional blood-brain barrier. Recently, we found that disruption of the microcirculation during acute hypertension is greater in area postrema than in the adjacent brain stem. In contrast, hyperosmolar disruption of the microcirculation is greater in brain stem. The objective of this study was to compare ultrastructural characteristics of the microcirculation in area postrema and adjacent brain stem.We studied 5 Sprague-Dawley rats. Horseradish peroxidase was injected intravenously and allowed to circulate for 1, 5 or 15 minutes. Following perfusion of the upper body with 2.25% glutaraldehyde in 0.1 M sodium cacodylate, the brain stem was removed, embedded in agar, and chopped into 50-70 μm sections with a TC-Sorvall tissue chopper. Sections of brain stem were incubated for 1 hour in a solution of 3,3' diaminobenzidine tetrahydrochloride (0.05%) in 0.05M Tris buffer with 1% H2O2.

Surgical Approaches to the Brain Stem

1993 ◽  
Vol 4 (3) ◽  
pp. 457-468 ◽  
Author(s):  
Dennis Y. Wen ◽  
Roberto C. Heros
Keyword(s):  
Brain Stem ◽  
Surgical Approaches ◽  
The Brain

ADRENERGIC INPUTS TO THE AMYGDALA AND THE CONTROL OF GONADOTROPHIN RELEASE

1979 ◽  
Vol 90 (3) ◽  
pp. 385-393 ◽  
Author(s):  
José Borrell ◽  
Flavio Piva ◽  
Luciano Martini
Keyword(s):  
Brain Stem ◽  
Dopamine Receptor ◽  
Serum Levels ◽  
Female Rats ◽  
Receptor Blocker ◽  
Dopaminergic Drug ◽  
Gonadotrophin Secretion ◽  
Biphasic Effect ◽  
Adrenergic Blocker ◽  
The Brain

ABSTRACT Drugs able to mimic or to antagonize the action of catecholamines have been implanted bilaterally into the basomedial region of the amygdala of adult castrated female rats. The animals were killed at different intervals after the implantation of the different drugs, and serum levels of LH and FSH were measured by radioimmunoassay. The results have shown that the intra-amygdalar implantation of the alpha-adrenergic blocker phenoxybenzamine induces a significant increase of the release both of LH and FSH. The implantation of the beta-adrenergic blocker propranolol brings about a rise of LH only. The dopamine receptor blocker pimozide stimulates the release of LH and exerts a biphasic effect (stimulation followed by inhibition) of FSH secretion. The alpha-receptor stimulant clonidine and the dopaminergic drug 2-Br-alpha-ergocryptine were without significant effects. From these observations it is suggested that the adrenergic signals reaching the basomedial area of the amygdala (possibly from the brain stem) may be involved in the modulation of gonadotrophin secretion.

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