GUSTATORY AND VISCERAL INPUTS TO THE AMYGDALA OF THE RAT - CONDITIONED TASTE-AVERSION AND INDUCTION OF C-FOS-LIKE IMMUNOREACTIVITY

Expression of proto-oncogene c-fos was immunohistochemically examined in the central and basolateral amygdaloid nuclei in rats after ingesti on pf taste solutions (0.5 M sucrose or 0.005 M saccharin), intragastr ic infusion of these solutions, or an intraperitoneal injection of mal aise-inducing lithium chloride (LiCl). C-Fos-like immunoreactive neuro ns were distributed most densely in the central nucleus in response to the LiCl injection, followed by the ingestion and intragastric infusi on of sucrose. The intraoral infusion of sucrose, but not of saccharin , elicited intense c-fos expression in the central nucleus after estab lishment of conditioned taste aversion to these taste stimuli. The res ults are discussed in terms of post-ingestional factors and the condit ioned illness reaction after taste aversion learning. (C) 1997 Elsevie r Science Ireland Ltd.