GALPARAN INDUCES IN-VIVO ACETYLCHOLINE-RELEASE IN THE FRONTAL-CORTEX

The chimeric peptide galparan (galanin(1-13)-mastoparan) induced the i n vivo release of acetylcholine in the frontal cortex of rats when inj ected intracerebroventricularly, i.c.v. The ACh-releasing effects of g alparan are reversible, dose-dependent, and not exerted at galanin rec eptors or at sites where mastoparan acts. Pertussis toxin pretreatment (i.c.v.) of the rats for 96 h prior to injection of galparan or of ma stoparan completely prevented the ACh-releasing effects of both galpar an and mastoparan. It appears that galparan acts at a novel site in th e release of ACh in the cerebral cortex in vivo.