Effects of the glutamate analogue AMPA and its interaction with antagonists on cultured rat spinal and brain stem neurones.

Glutamate and the glutamate analogue AMPA ((RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid) caused depolarizations of cultured rat spinal and brainstem neurones which were reversibly antagonized by the glutamate antagonist glutamic acid diethylester (GDEE) but not by 2-amino-5-phosphonovalerate (APV), an N-methyl-D-aspartate (NMDA) antagonist. In contrast, depolarizations by NMDA were blocked by APV but not by GDEE. These results suggest that the depolarization by AMPA is caused by the activation of glutamate/quisqualate-preferring receptors.