Effects of Substance P and Calcitonin Gene-Related Peptides on Cortical Taste Neurons in Rats

Abstract

The cortical taste area (CTA) in rats is located in the granular insular (GI) and dysgranular insular (DI) areas and contains neurons with receptors for glutamate [1]. Substance P (SP) and calcitonin gene-related peptide (CGRP)-like immunoreactivity, however, is found in the gustatory pathway from the tongue to the CTA, although there is a mismatch between nerve terminals and receptors for the peptides. CGRP-containing fibers [2], and SP receptors [3] are numerous in the DI area, whereas CGRP receptors [4] are numerous in the GI area and SP fibers [5] spread throughout the insular cortex. In this study, we examined the distribution of neurons sensitive to these peptides in the CTA, and the effects on taste responses.