SEX-DIFFERENCES IN ACUTE SWIM STRESS-INDUCED CHANGES IN THE BINDING OF AMPA (ALPHA-AMINO-3-HYDROXY-5-METHYLISOXAZOLE-4-PROPIONIC ACID) AND KAINATE TO GLUTAMATE RECEPTORS IN MOUSE FOREBRAIN

Sex differences were found in the binding of [H-3]AMPA and [H-3]kainate to glutamate receptors in synaptosomal membranes prepared from mouse forebrain. The number of low affinity [H-3]AMPA binding and the affinity of [H-3]kainate binding was higher in membranes prepared from male mice than from females. Acute swim stress (3 min at 32 degrees C) decreased the number of low affinity [H-3]AMPA binding sites and the affinity of [H-3]kainate binding in membranes prepared from male mouse forebrain, but not in those prepared from female mice forebrain. As kainate is known to interact with low affinity AMPA binding sites, these observed changes may be associated with binding sites common to AMPA and kainate. They may represent a functional down-regulation of AMPA/kainate binding sites. These sex differences in binding to non-NMDA subclasses of glutamate receptors are similar to than those found in the binding of MK-801 to the NMDA subclass of glutamate receptors, in that the effects of acute swim stress were more pronounced in membranes prepared from male than from female mice. The number of low affinity [H-3]AMPA binding sites were decreased by acute swim stress in membranes from male mice, whereas the number of low affinity [H-3]MK-801 binding sites increased following acute swim stress.