Adrenalectomy reduces peripheral neural responses to gustatory stimuli in the rat.

The adrenalectomized rat, because of excessive body sodium loss, has been an important animal model for studying the physiological mechanisms underlying salt ingestion. To investigate the mediation by peripheral taste responsivity of changes in salt intake, multiunit responses of the chorda tympani nerve to various concentrations of NaCl, KCl, and LiCl, hydrochloric acid, and quinine hydrochloride were recorded from 18 adrenalectomized or intact male Sprague-Dawley rats. To control for a generalized decrease in sensory sensitivity, recordings from this auriculotemporal nerve to tactile stimulation of the pinna were also performed. There were no group differences in amplitude of the integrated neural responses to tactile stimulation. The largest decrease in gustatory responsivity occurred for suprathreshold concentrations of NaCl and LiCl. Data are discussed with reference to possible mechanisms underlying this neural alteration and the role that reductions in salt taste responsivity play in mediating increases in salt intake. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)