Effects of area postrema lesions and bilateral subdiaphragmatic afferent vagotomy on emetine-induced conditioned taste avoidance in rats.

Abstract

We investigated the effect of area postrema lesions and selective vagotomy of afferent fibers on emetine-induced nausea in rats. We evaluated the acquisition of the conditioned taste avoidance (CTA) to 0.1% saccharin solution after conditioning with emetine dihydrochloride (5.54 mg/kg, i.p., 1% BW). The CTA was measured in three groups of rats: a bilateral subdiaphragmatic afferent vagotomy group, an area postrema lesion group, and a sham lesion group. The bilateral vagotomy and sham groups of rats showed acquisition of CTA within 2 days of the test date. Taste avoidance was never conditioned in the area postrema lesion group. These results indicate that the area postrema plays a crucial role in the induction of emetine-induced nausea.