NEW EVIDENCE THAT L‐GLUTAMATE IS A TRANSMITTER AT THE SQUID GIANT SYNAPSE

Abstract

Experiments are described showing unequivocally that transmission at the squid giant synapse can be reversibly blocked by L‐glutamate and its agonists kainate, quisqualate and AMPA, though not by NMDA. This effect is presumably brought about by desensitization. The glutamate antagonists cis‐2,3‐PDA, GAMS and the new quinoxalinediones CNQX and DNQX are also potent reversible blockers. These findings provide new evidence that L‐glutamate is a transmitter at the giant synapse and further suggest that the glutamate receptor may be of the non‐NMDA type. © 1989 The Physiological Society