Identification of vagal preganglionics that mediate cephalic phase insulin response

1990 ◽  
Vol 258 (2) ◽  
pp. R523-R530 ◽  
Author(s):  
H. R. Berthoud ◽  
T. L. Powley
Keyword(s):  
Portal Vein ◽  
Vagal Stimulation ◽  
Insulin Response ◽  
Motor Nucleus ◽  
Dorsal Motor Nucleus ◽  
Glucose Intake ◽  
Cephalic Phase ◽  
Pancreatic B Cells ◽  
Freely Moving ◽  
Hepatic Branch

To define the vagal circuitry mediating the cephalic phase insulin response (CPIR), this reflex was measured in conscious, freely moving rats that had previously undergone selective abdominal vagotomies that spared different columnar subpopulations of dorsal motor nucleus of the vagus (dmnX) neurons. The CPIR was defined as an increase of plasma insulin from basal at 2 min after the start of ingestion. The CPIR measured in peripheral blood after chow ingestion was reliable and significant (P less than 0.05) in rats with all branches intact, +24.9 +/- 5.1 microU/ml (+130% increase from basal); rats with only the two gastric branches and the hepatic branch intact, +27.0 +/- 3.5 microU/ml (+153%); and rats with only the hepatic branch intact, +13.5 +/- 4.8 microU/ml (+188%). No significant response occurred in animals with only the two celiac branches intact, +1.8 +/- 1.8 microU/ml (+15%) or in those with none of the branches intact, +3.9 +/- 3.3 microU/ml (+21%). The CPIRs measured in portal vein blood were generally larger but showed the same pattern across groups. Plasma glucose measurements of portal vein blood indicated that with chow ingestion no significant absorption had occurred by 2 min, whereas with either milk or glucose intake absorption did occur. Subsequent bilateral electrical cervical vagal stimulation-induced insulin and glucagon responses in the same animals under anesthesia showed the same branch dependency. It is concluded that the CPIR is mediated by the two gastric and the hepatic branches but not the two celiac vagal branches. The perikarya of the preganglionics innervating the pancreatic B-cells are contained within a large pool occupying the two medial columns of the dmnX.

Topography of efferent vagal innervation of the rat gastrointestinal tract

1991 ◽  
Vol 260 (1) ◽  
pp. R200-R207 ◽  
Author(s):  
H. R. Berthoud ◽  
N. R. Carlson ◽  
T. L. Powley
Keyword(s):  
Vagal Stimulation ◽  
The Other ◽  
Motor Nucleus ◽  
Anterograde Tracing ◽  
Entire Colon ◽  
Dorsal Motor Nucleus ◽  
Carbocyanine Dye ◽  
Vagal Innervation ◽  
Hepatic Branch ◽  
Entire Stomach

The gastrointestinal territories innervated by the gastric, celiac, and hepatic abdominal vagi were identified in rats with selective branch vagotomies by means of 1) anterograde tracing with the carbocyanine dye DiI injected into the dorsal motor nucleus and 2) measurement of cervical vagal stimulation-induced motility responses throughout the gut axis. Presence of DiI-labeled vagal terminals in the myenteric plexus and evoked motility responses were well correlated across the sampled gastrointestinal (GI) sites. In animals with only the two gastric branches intact, the entire stomach and the most proximal duodenum showed significant motility responses and were densely innervated, having DiI-labeled vagal terminals in almost every ganglion. The hepatic branch was found to primarily innervate the duodenum, with minor projections to the distal antral stomach and the intestines. The two celiac branches were found to almost exclusively innervate the jejunum, ileum, cecum and entire colon, and, together with the other vagal branches, the duodenum. Therefore, while there is some degree of specific innervation by the abdominal vagal branches of the oral-to-anal gut axis, which could be called "viscerotopic," the considerably overlapping innervation of the duodenum does not satisfy a viscerotopy criterion and needs further functional analysis.

Retrograde tracer technique for assessment of selective and total subdiaphragmatic vagotomies

1987 ◽  
Vol 253 (2) ◽  
pp. R361-R370 ◽  
Author(s):  
T. L. Powley ◽  
E. A. Fox ◽  
H. R. Berthoud
Keyword(s):  
Motor Nucleus ◽  
Tracer Technique ◽  
Fluorescent Tracer ◽  
Practical Test ◽  
Dorsal Motor Nucleus ◽  
Diffusion Characteristics ◽  
Different Types ◽  
Physiological Tests ◽  
Hepatic Branch ◽  
Equal Effectiveness

A new protocol that provides a sensitive, reliable, and practical test for completeness of selective as well as total subdiaphragmatic vagotomies is described. This protocol employs a microscopic inventory of retrogradely labeled neurons in topographically distinct regions of the dorsal motor nucleus to determine which vagal branches have been surgically destroyed. Physiological experiments for validation and observations on the use of the method with 243 rats indicate that the protocol described can assess total as well as at least 11 different types of selective subdiaphragmatic vagotomies, including surgeries for which no assays have existed. Furthermore, the technique can identify cases where a branch is only partially destroyed. Other strengths include the facts that the protocol provides a simultaneous inventory of the different branches in a single test, is not influenced by the general health of the animal, and does not interfere with concurrent behavioral or physiological tests. Limitations include the facts that the tracer inventory requires a minimal survival period, can only be done postmortem, and has low resolution for cuts of the vagal hepatic branch. Aspects of the protocol critical to its implementation, including specifics for using the fluorescent tracer true blue, are discussed. Other tracers with similar diffusion characteristics, such as fluoro-gold and fast blue, can be used with equal effectiveness with this protocol.

Stimulation of the paraventricular nucleus modulates the activity of gut-sensitive neurons in the vagal complex

1999 ◽  
Vol 277 (1) ◽  
pp. G79-G90 ◽  
Author(s):  
Xueguo Zhang ◽  
Ronald Fogel ◽  
William E. Renehan
Keyword(s):  
Electrical Stimulation ◽  
Paraventricular Nucleus ◽  
Good Evidence ◽  
Small Subset ◽  
Motor Nucleus ◽  
Dorsal Motor Nucleus ◽  
Cephalic Phase ◽  
Stimulation Of ◽  
Vagal Function

There is good evidence that stimulation of the lateral hypothalamus excites neurons in the dorsal vagal complex (DVC), but the data regarding the role of the paraventricular nucleus (PVN) in vagal function are less clear. The purpose of this study was to clarify the effect of PVN stimulation on the activity of neurons in the DVC. We utilized extracellular and intracellular neuronal recordings with intracellular injections of a neuronal tracer to label individual, physiologically characterized neurons in the DVC of rats anesthetized with pentobarbital sodium. Most (80%) of the gut-sensitive dorsal motor nucleus of the vagus (DMNV) neurons characterized in this study exhibited a change in activity during electrical stimulation of the PVN. Stimulation of the PVN caused an increase in the spontaneous activity of 59% of the PVN-sensitive DMNV neurons, and the PVN was capable of modulating the response of a small subset of DMNV neurons to gastrointestinal stimuli. This study also demonstrated that the PVN was capable of influencing the activity of neurons in the nucleus of the solitary tract (NST). Electrical stimulation of the PVN decreased the basal activity of 66% of the NST cells that we characterized and altered the gastrointestinal response of a very small subset of NST neurons. It is likely that these interactions play a role in the modulation of a number of gut-related homeostatic processes. Increased or decreased activity in the descending pathway from the PVN to the DVC has the potential to alter ascending satiety signals, modulate vago-vagal reflexes and the cephalic phase of feeding, and affect the absorption of nutrients from the gastrointestinal tract.

Early insulin response after food intake in geese

1992 ◽  
Vol 263 (4) ◽  
pp. R782-R784
Author(s):  
H. Karmann ◽  
N. Rideau ◽  
T. Zorn ◽  
A. Malan ◽  
Y. Le Maho
Keyword(s):  
Insulin Secretion ◽  
Plasma Glucose ◽  
Plasma Insulin ◽  
Insulin Response ◽  
Insulin Level ◽  
Food Ingestion ◽  
Standard Meal ◽  
Cephalic Phase ◽  
Early Insulin Response ◽  
Freely Moving

Plasma glucose and insulin levels were measured in chronically catheterized, freely moving, undisturbed geese, which were offered a free standard meal after an overnight fast. The insulin level markedly rose within the first minute after the start of food ingestion, whereas plasma glucose did not increase. This early insulin response was not correlated with the size of the meal. In contrast, both postabsorptive insulin response and plasma glucose changes were dependent on meal size. When a small amount of food (2-6 g) was eaten, insulin returned to basal level within 30 min, whereas plasma glucose remained unchanged. Larger meals (15-20 g) maintained plasma insulin at a higher level and induced a sustained rise of plasma glucose. These results indicate that there is a cephalic phase of insulin secretion at the beginning of the meal in birds as previously described in mammals.

scholarly journals NMDA Receptor-Dependent Synaptic Activity in Dorsal Motor Nucleus of Vagus Mediates the Enhancement of Gastric Motility by Stimulating ST36

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Xinyan Gao ◽  
Yongfa Qiao ◽  
Baohui Jia ◽  
Xianghong Jing ◽  
Bin Cheng ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Gastric Motility ◽  
Low Frequency ◽  
Synaptic Activity ◽  
Motor Nucleus ◽  
Dorsal Motor Nucleus ◽  
Vagal Reflex ◽  
Precise Molecular Mechanism ◽  
Lines Of Evidence

Previous studies have demonstrated the efficacy of electroacupuncture at ST36 for patients with gastrointestinal motility disorders. While several lines of evidence suggest that the effect may involve vagal reflex, the precise molecular mechanism underlying this process still remains unclear. Here we report that the intragastric pressure increase induced by low frequency electric stimulation at ST36 was blocked by AP-5, an antagonist of N-methyl-D-aspartate receptors (NMDARs). Indeed, stimulating ST36 enhanced NMDAR-mediated, but not 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propanoic-acid-(AMPA-) receptor-(AMPAR-) mediated synaptic transmission in gastric-projecting neurons of the dorsal motor nucleus of the vagus (DMV). We also identified that suppression of presynapticμ-opioid receptors may contribute to upregulation of NMDAR-mediated synaptic transmission induced by electroacupuncture at ST36. Furthermore, we determined that the glutamate-receptor-2a-(NR2A-) containing NMDARs are essential for NMDAR-mediated enhancement of gastric motility caused by stimulating ST36. Taken together, our results reveal an important role of NMDA receptors in mediating enhancement of gastric motility induced by stimulating ST36.

α-Synuclein pathology in the spinal cords of neurologically asymptomatic aged individuals

Neurology ◽  
2006 ◽  
Vol 66 (7) ◽  
pp. 1100-1102 ◽  
Author(s):  
K. J. Klos ◽  
J. E. Ahlskog ◽  
K. A. Josephs ◽  
H. Apaydin ◽  
J. E. Parisi ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Substantia Nigra ◽  
Basal Forebrain ◽  
Locus Ceruleus ◽  
Raphe Nucleus ◽  
Motor Nucleus ◽  
Lewy Neurites ◽  
Dorsal Motor Nucleus ◽  
Asymptomatic Individuals

The authors assessed the frequency of spinal cord α-synuclein pathology in neurologically asymptomatic individuals older than 60 years of age (N = 106). Using α-synuclein immunohistochemistry, nine cases (8%) had incidental Lewy neurites in the intermediolateral column and at least some α-synuclein pathology in the dorsal motor nucleus of the vagus, locus ceruleus, and central raphe nucleus. Sparse α-synuclein pathology was also detected in the substantia nigra, basal forebrain, amygdala, or cortex in all but two cases.

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