Trans-ACPD induces a slow post-stimulus inward tail current (IADP) in guinea-pig olfactory cortex neurones in vitro

The metabotropic glutamate receptor agonist trans-(+/-)-1-amino-1,3-cyclopentanedicarboxylic acid (trans-ACPD) produced a slow, persistent excitation of guinea-pig olfactory cortical neurones in vitro, and the appearance of a prominent post-stimulus after depolarization. The corresponding slow inward tail current (IADP) revealed under voltage clamp was insensitive to tetrodotoxin (or atropine) but was blocked by Cd2+ or tetrabutylammonium. The IADP properties resembled those of the slow inward tail current induced by muscarinic agonists in these neurones, suggesting a common intracellular transduction mechanism.