Galanin-evoked acetylcholine release in the rat striatum is blocked by the putative galanin antagonist M15.

The effect of the putative galanin (GAL) antagonist M15 on the GAL-evoked release of acetylcholine (ACh) was investigated in the rat striatum using microdialysis and HPLC techniques. GAL (3 nmol/10-mu-l), applied in the lateral ventricle (i.c.v.) or perfused through the microdialysis membrane into the striatum, was found to enhance basal ACh release. The GAL-evoked release of striatal ACh was completely blocked by M15 (3 nmol/10-mu-l), administered either i.c.v. or into the striatum. This finding suggests that GAL stimulates the basal ACh release in the rat striatum by a direct action of the peptide on striatal GAL receptors.