Neurons in the caudal ventrolateral medulla mediate the sympathoinhibitory effects of CCK

Abstract

The gastrointestinal hormone cholecystokinin (CCK) inhibits a subset of presympathetic neurons in the rostroventrolateral medulla (RVLM) that may be responsible for driving the sympathetic vasomotor outflow to the gastrointestinal circulation. We tested the hypothesis that the central neurocircuitry of this novel reflex is similar to that of other sympathoinhibitory reflexes that utilise a relay in the caudal ventrolateral medulla (CVLM). Blood pressure, heart rate and splanchnic sympathetic nerve discharge (SSND) were monitored in anesthetised (1.5% halothane in 100% O 2 ), paralysed male Sprague‐Dawley rats. After electrophysiological localisation of..