Trans-ACPD inhibits cAMP formation via a pertussis toxin-sensitive G-protein

In primary cultured striatal neurons we found that (+-)-trans-1-amino-cyclopentyl-1,3-dicarboxylate (trans-ACPD) could inhibit forskolin-induced cAMP formation in a dose-dependent manner (EC50 156 +/- 38 microM, n = 5, maximal inhibition 37.8 +/- 1.2, n = 37). The trans-ACPD-induced inhibition was totally abolished in neurons preincubated with Bordetella pertussis toxin (1 microgram/ml), demonstrating the involvement of a G-protein. This is the first report in intact neurons of a glutamate metabotropic receptor negatively coupled to cAMP formation.