Electrophysiological and autoradiographical evidence of V1 vasopressin receptors in the lateral septum of the rat brain

摘要: Abstract Extracellular recordings were obtained from single neurons located in the lateral septum, an area known to receive a vasopressinergic innervation rat brain. Approximately half of tested responded 8-L-arginine vasopressin (AVP) by marked increase firing rate at concentrations greater than 1 nM. The effect was blocked synthetic structural analogues possessing antagonistic properties on peripheral and oxytocin receptors. Oxytocin much less potent septal neurons, selective oxytocic agonist totally ineffective. action neuronal mimicked vasopressor [2-phenylalanine,8-ornithine]vasotocin but not antidiuretic 1-deamino[8-D-arginine]vasopressin. In parallel study, sites that bind [3H]AVP low concentration (1.5 nM) found vitro autoradiography septum. Adjacent sections also incubated with 1.5 mM and, addition, 100 nM or 1-deamino[8-D-arginine]vasopressin--i.e., same compounds as those used for electrophysiological study. Results showed agonist, displaced [3H]AVP, thus indicating binding detected septum V1 (vasopressor type) rather V2 (antidiuretic Based evidence, we conclude these receptors, when occupied, lead increased neurons.