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

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

1989 ◽  
Vol 257 (1) ◽  
pp. G24-G29
Author(s):  
W. D. Barber ◽  
C. S. Yuan

The brain stem neuronal responses to electrical stimulation of gastric branches of the ventral vagal trunk serving the proximal stomach were localized and evaluated in anesthetized cats. The responses were equally distributed bilaterally in the region of nucleus solitarius in the caudal brain stem. The mean latency of the response was 289 +/- 46 (SD) ms, which translated into a conduction velocity of less than 1 m/s based on the distance between the stimulating and recording electrodes. The responses consisted of single and multiple spikes that showed slight variability in the latency, indicating orthodromic activation via a synapse in approximately 98% of the responses recorded. Forty two percent of the units tested showed evidence of convergence of input from vagal afferent fibers in different branches of the ventral vagal trunk that served the proximal stomach. The resultant activity pattern of the unitary response appeared to be the product of 1) the gastric sensory input or modality conveyed by the afferent source and 2) the time of arrival and diversity of modalities served by other gastric afferents impinging on the unit. This provides a mechanism capable of responding on the basis of specific sensory modalities that dynamically reflect ongoing events monitored and conveyed by other gastric afferents in the region.


2007 ◽  
Vol 292 (3) ◽  
pp. R1092-R1100 ◽  
Author(s):  
V. Baptista ◽  
K. N. Browning ◽  
R. A. Travagli

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.


1992 ◽  
Vol 262 (1) ◽  
pp. G74-G80 ◽  
Author(s):  
C. S. Yuan ◽  
W. D. Barber

Gastric vagally evoked extracellular unitary responses were recorded in the hypothalamus of anesthetized cats. The evoked unitary responses were localized in the paraventricular dorsomedial region, ventromedial nucleus, and lateral hypothalamus. The mean latency of the gastric vagally evoked hypothalamic neuronal responses in these three areas ranged from 368 +/- 39.8 to 371 +/- 45.2 (SD) ms. The majority (82%) of the gastric vagally evoked hypothalamic responses consisted of one to five spikes, while the remaining 18% were tonically active units. The vagal effect was inhibitory in 78% of the tonically active hypothalamic units responding to gastric vagal input. Convergence of gastric vagal input on single hypothalamic units from afferents in the dorsal and ventral vagal trunks was observed. Units were identified in the hypothalamus that responded to activation of mechanoreceptors in the proximal stomach by an intragastric balloon. This study provided new direct evidence of the density, localization, and characteristics of neuronal processing of gastric vagal input from the proximal stomach in the hypothalamus. The reciprocal connections between these areas of the hypothalamus and nucleus tractus solitarius in the caudal brain stem suggest that the hypothalamus may serve an important role in modulating the input of primary vagal afferent input from the proximal stomach.


Author(s):  
Xiao Di ◽  
M. Ragab ◽  
Mark G. Luciano

Background:To predict success of endoscopic third ventriculostomy (ETV) in patients with obstructive hydrocephalus, we evaluated pre- and post- operative phase-contrast cine magnetic resonance images (PC MRI) on cerebrospinal fluid (CSF), cine flow in basal cisterns around the brain stem, and cervical medullar junction (CMJ) retrospectively.Methods:The study involved 102 patients with mean age of 36.74±23.25, and F/M = 1.55. All patients had PC MRI taken both pre- and post-operatively. A dynamic MRI video of PC MRI was reviewed at sagittal, axial, and coronal sections to determine cistern flows around the brain stem and CMJ. For quantitative analysis, quadrants were divided around midbrain axially to evaluate interpeduncular, quadrageminal, and ambient cisterns of both sides using scores of 0 to 60. Pre- and post- pontine and CMJ flows were shown in sagittal view and scored 0 to 20, and lateral cerebellopontine cisterns of both sides were measured on coronal image and scored 0 to 20.Results:No significant difference in CSF flow was seen from three individual views and total cine score, or between ETV success and failure groups by multivariate analysis of variance. Kaplan-Meier Analysis and Spearman's Correlation Test produced no relationship between MRI cine flow scores and interval period after surgery to ETV failure.Conclusion:PC MRI cine flow failed to demonstrate significant differences between successful and failed ETV groups. This indicates in addition to achieving an adequate fenestration, CSF pathways beyond the basal cisterns around the brain stem and CMJ may play an essential role in achieving ETV success.


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

1995 ◽  
Vol 268 (5) ◽  
pp. R1327-R1331 ◽  
Author(s):  
S. Laye ◽  
R. M. Bluthe ◽  
S. Kent ◽  
C. Combe ◽  
C. Medina ◽  
...  

To test the possibility that the vagus nerve is involved in the communication between the immune system and the brain, we injected sham-operated and vagotomized mice with physiological saline or lipopolysaccharide (LPS; 400 micrograms/kg ip). Vagotomy attenuated LPS-induced depression of general activity measured 2 h after treatment but did not alter the increase in plasma levels of IL-1 beta in response to LPS. In addition, vagotomy abrogated the LPS-induced increase in the levels of transcripts for IL-1 beta, as determined by semiquantitative polymerase chain reaction after reverse transcription, in the hypothalamus and hippocampus, but not in the pituitary of vagotomized mice. This relationship between the effects of vagotomy on the behavioral effects of LPS and the LPS-induced brain expression of IL-1 beta mRNA indicates that vagal afferent fibers play a prominent role in the pathways of communication between the immune system and the brain.


Author(s):  
Matheus Vinícius de Souza Carneiro ◽  
Ricardo de Queiroz Freitas ◽  
Lucas Baltar Rodrigues ◽  
Wenberger Lanza Daniel de Figueiredo ◽  
Geane Antiques Lourenço ◽  
...  

Aims: By using histological analysis, the study aims to evaluate the effect of a nutraceutical based on the Amazonian fruits of camu-camu (Myrciaria dubia (Kunth) Mc Vaugh), acai (Euterpe precatoria Mart.) and guarana (Paullinia cupana) on the brain tissue (hippocampus) of dyslipidemic rats. Methodology: Preclinical trials were conducted using male and female rats (n=30) of the Wistar strain (Rattus norvegicus) that were randomly divided into five groups (G) (n=6). G1 was control, G2 was induced to obesity with consumption of experimental feed (hypercaloric and hyperlipidic), G3 was induced to obesity with consumption of experimental feed and treated with simvastatin (50 mg/kg/day), and G4 and G5, which were induced to obesity with the consumption of experimental feed and supplemented with 100 mg/kg/day and 200 mg/kg/day of the formulation, respectively. The study period was 72 days, and, for 37 days, induction to obesity was performed with the experimental feed (hypercaloric and hyperlipidic). During the following weeks, for 35 days, after division of the groups, certain groups received, in parallel, treatment with simvastatin (G3) or supplementation with the nutraceutical (G4 and G5). Subsequently, histological slides of the brain tissue stained with violet cresyl were elaborated, photographed and analyzed. Results: No significant differences were observed between the mean of intact neurons among the experimental groups induced to obesity. The neurotoxic effect, evidenced by the significant difference between the mean of intact neurons between the control group and obesity-induced groups, corroborates the findings of neuronal damage and degenerative processes reported in the literature. Conclusion: The nutraceutical based on Amazonian fruits was not able to prevent the neurotoxic effect arising from the hyperlipidic and hypercaloric diet, and therefore did not present a neuroprotective effect in Wistar rats under the conditions established in the experiment.


2020 ◽  
Author(s):  
Tetsuya Kusunoki ◽  
Tomohiro Kawaguchi ◽  
Atsuhiro Nakagawa ◽  
Yuta Noguchi ◽  
Shinichiro Osawa ◽  
...  

Abstract Objective: We developed an actuator-driven pulsed water jet device (ADPJ) for flexible neuroendoscopy to achieve effective tissue dissection with vasculature preservation. Although flexibility is a strong advantage for minimally invasiveness, the effect of the ductile curvature on the dissection profiles remains unknown. The purpose of this study was to clarify the impact of the curvature change of the ADPJ connecting tube on the dissection safety and efficacy.Results: Three ADPJ connecting tubes with different inner diameters (1.0, 0.75, 0.5 mm) were used to dissect the brain phantom. They were bent at 3 angles: 0 °, 60 °, and 120 °. The dissection profiles were evaluated using the mean depth and coefficient of variation (CV) for efficacy and safety, respectively.The larger inner diameter connecting tube dissected more deeply. The dissection depth was not changed regardless of the curvature degree in each tube. There was no significant difference in CVs regardless of inner diameter and curvature. The ductile curvature of the flexible neuroendoscope did not affect the efficacy and safety of the ADPJ dissection profile. Among the numerous instruments, tube-formed devices, including suction and injecting devices such as ADPJ, can be used safely and effectively without flexibility-related limitations.


2014 ◽  
Vol 11 (1) ◽  
pp. 69-73 ◽  
Author(s):  
M Uddin ◽  
MHR Sarker ◽  
ME Hossain ◽  
MS Islam ◽  
MB Hossain ◽  
...  

This study was intended to investigate some aspects of the morphometric characteristics of the neurocranium in domestic cat (Felis catus) of Bangladesh. Twenty adult domestic cat including 10 males and 10 female were euthanized using diazepam (@ 20 mg/kg) and their skulls were macerated to give morphometric parameters. Student t-test with level of significance set at 5% (p < 0.05) was used to analyze the obtained values. The mean (mean ± SE) neurocranial volume was 28 ± 0.97 ml, neurocranial length was 6.63 ± 0.77 cm, and the neurocranial height and index were 3.32 ± 0.38 cm and 49.83%, respectively. The mean height and width of the foramen magnum were 1.32 ± 0.09 cm and 1.35 ± 0.08 cm, respectively, while the foramen index was below 100 at 90.72 ± 4.93. Parameters for the foramen magnum index showed significant difference between both sexes at p < 0.05. The foramen magnum showed shape variations and there were multiple hypoglossal foramina in over 80% of the cats. Foramen magnum index was positively correlated with neurocranial volume. The results were discussed in terms of the usage of morphologic and morphometric characteristics of cranium and skulls in several basic and clinical applications in cat such as estimation of the brain density and the use of the cat for cranial pressure experiments. DOI: http://dx.doi.org/10.3329/bjvm.v11i1.17302 Bangl. J. Vet. Med. (2013). 11 (1): 69-73


1999 ◽  
Vol 277 (3) ◽  
pp. G626-G630 ◽  
Author(s):  
Chun-Su Yuan ◽  
Anoja S. Attele ◽  
Ji An Wu ◽  
Liu Zhang ◽  
Zhi Q. Shi

Afferent sensory fibers are the primary neuroanatomic link between nutrient-related events in the gastrointestinal tract and the central neural substrates that modulate ingestion. In this study, we evaluated the peripheral gastric effects of leptin (OB protein) on brain stem neuronal activities using an in vitro neonatal rat preparation. We also tested gastric leptin effects as a function of age in neonates. For ∼33% of the nucleus tractus solitarius units observed, gastric leptin (10 nM) produced a significant activation of 188.2 ± 8.6% (mean ± SE) compared with the control level of 100% ( P < 0.01). Concentration-dependent leptin effects have also been shown. The remaining neurons (67%) had no significant response to gastric leptin application. Next, we evaluated the peripheral gastric effects of leptin (10 nM) on brain stem unitary activity in three different age groups (1–2 days old, 3–5 days old, and 7–8 days old) of neonatal rats. In the 1- to 2-day-old and the 3- to 5-day-old groups, we observed that response ratios and activity levels were similar. However, there was a significant difference between the 7- to 8-day-old group and the two younger age groups in both the response ratios and the activation levels. The percentage of activation responses increased from ∼26% in the 1- to 2-day-old and the 4- to 5-day-old age groups to 70% in the 7- to 8-day-old group ( P < 0.05). The level of activation increased from 168.3 ± 2.7% (compared with the control level) in the 1- to 2-day-old and the 4- to 5-day-old age groups to 231.4 ± 11.9% in the 7- to 8-day-old group ( P < 0.01). Our data demonstrate that peripheral gastric leptin modulates brain stem neuronal activity and suggest that gastric leptin has a significantly stronger effect in the 7- to 8-day-old animals than in the younger neonates.


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