Abstract
Background:Most peripheral afferent fibers involved in swallowing travel through the glossopharyngeal and vagus nerves and terminate in the nucleus of the tractus solitarius (NTS) and nodose ganglion (NG). Sensory neurons within the NTS and NG contain several neurotransmitters, including acetylcholine, histamine, serotonin and dopamine. The roles of these four neurotransmitters were investigated.Methods:The effects of atropine (muscarinic cholinergic receptor antagonist); pyrilamine maleate (PM, histamine H1 receptor antagonist); cimetidine (histamine H2 receptor antagonist); 8‐hydroxy‐2‐(di‐n‐propylamino)‐tetralin (8‐OH‐DPAT, specific 5‐HT1A receptor agonist); and selective dopamine D1 receptor antagonist (Sch‐23390) on the number of swallows elicited by distilled water in anesthetized guinea pigs were investigated.Results:Atropine (0.2 mg/kg) inhibited swallowing by approximately 70%; PM (30 mg/kg) inhibited swallowing by approximately 60%; cimetidine (30 mg/kg) inhibited swallowing by approximately 52.9% and Sch‐23390 (chronic treatment) inhibited swallowing by approximately 40%. In contrast, 8‐OH‐DPAT did not alter the number of swallows. Chronic pretreatment of Sch‐23390 markedly decreased the substance P (SP) content in the pharyngeal mucosa and the esophagus.Conclusion:These findings indicate that acetylcholine, histamine and dopamine are involved in the regulation of the swallowing reflex, whereas it is unlikely that serotonin is involved.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
