Electrophysiological Responses of Nucleus Tractus Solitarius Neurons to CCK and Gastric Distension in Newborn Lambs

Abstract

The effect of cervical vagus nerve stimulation, gastric distension and CCK-8S administration was studied on the activity of 120 neurons located in the nucleus tractus solitarius (NTS) of anesthetized newborn lambs. One hundred cells responded to the three different inputs. The distribution of the cells in the NTS was from 3 mm rostral to 3 mm caudal to the obex, the major responsive cells being located at the level of the obex. Neurons were either excited or inhibited by gastric distension and CCK-8S, and the responses to these two stimuli were always in the same direction. A small number of cells responded to gastric distension and CCK-8S but not to vagus nerve stimulation. Injection of the CCK-A receptor antagonist 2-NAP abolished both the responses to CCK-8S and to gastric distension. The results are consistent with the idea that CCK-8S acts directly on vagal mechanoreceptive endings in the gastric corpus close to duodenum. These results from lambs may reflect the pathway by which gastric distension and peripheral CCK-8S modulate NTS cells activity during colostrum ingestion, which could in turn activate structures related to learning and memory processes involved in the development of mother preference.

Systematic review of olfactory shifts related to obesity

“…In this feedback mechanism, NTS regulates the DMV's motor output to stomach with its GABAergic input (ie, via neurons that produce gama‐aminobutyric acid) . NTS not only regulates DMV activity on the stomach but also works as a hub for the supraspinal effects of vagal sensory axons that carries the viscerosensation of the gastrointestinal system, including gastric distention . NTS conveys gustatory and also visceroception information including gastric distention to the insular cortex, and as a result, gastric distention activates satiety circuitry in the human brain .…”

Mother–Young Relationships in Sheep: A Model for a Multidisciplinary Approach of the Study of Attachment in Mammals

“…A higher neural activation in the NTS and in the AP is obtained in newborn lambs receiving a bolus of either saline or colostrum than in lambs receiving no fluids (76). Electrophysiological studies confirm that some NTS neurones respond specifically to gastric distension, peripherally administered CCK or vagal nerve stimulation (66), a response that is abolished after injections of a CCK receptor antagonist. This supports the hypothesis that endogenous CCK acts directly on vagal endings and may reflect the pathway by which gastrointestinal signals triggers filial attachment.…”

“…Behavioural disturbances are produced by an antagonist that is unable to cross the blood–brain barrier, suggesting that the gut peptide acts at peripheral levels. One likely mechanism is that plasma CCK that does not cross the blood–brain barrier binds to peripheral receptors (64, 65) and activates sensitive fibres of the vagal nerve (66) that projects to the brain stem. The exact same pathways would be involved with the activation of mechanoreceptors after gastric distension (66).…”

“…One likely mechanism is that plasma CCK that does not cross the blood–brain barrier binds to peripheral receptors (64, 65) and activates sensitive fibres of the vagal nerve (66) that projects to the brain stem. The exact same pathways would be involved with the activation of mechanoreceptors after gastric distension (66). In our recent studies, we have shown that suckling also triggers the release of plasma oxytocin.…”

Diversité des relations affiliatives chez les ovins en situation d’élevage : mécanismes comportementaux et neurobiologiques

“…Les perturbations induites sont obtenues que l'antagoniste ait la propriété de traverser la barrière hémato-encéphalique ou pas, ce qui suggère que le peptide intestinal agit au niveau périphérique. Un mécanisme vraisemblable, schématisé sur la figure 1, est que la CCK se lie aux récepteurs périphériques et, active les fibres sensitives du nerf vague qui innervent le tronc cérébral (Guevara-Guzman et al 2005). Cette voie sensorielle serait également impliquée dans l'activation des mécanorécepteurs lors de la distension gastrique.…”