TRANSIENT INCREASE OF AMPA AND NMDA RECEPTOR-BINDING IN THE BARREL CORTEX OF MICE AFTER TACTILE STIMULATION

The effects of sensory stimulation and sensory conditioning upon [H-3] MK-801 ,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine] binding to N -methyl-D-aspartate (NMDA) receptor sites and [H-3]AMPA lpha-amino-3-h ydroxy-5-methylisoxasole-4-propionic acid) binding to AMPA receptor si tes were examined in the primary somatosensory (SI) cortex of mice. Fo llowing short-lasting unilateral tactile stimulation of a selected row of vibrissae, and tactile stimulation paired with noxious stimulus (t he pairing procedure was found to alter cortical representation of vib rissae), in vitro receptor binding autoradiography was performed on th e sections of the barrel cortex of mice. One hour after the end of tac tile stimulation or training procedure there was an increase of [H-3]M K-801 and [H-3]AMPA binding in the corresponding row of barrels in lay er IV of the SI cortex of adult mice. These effects disappeared 24 h a fter the end of each experimental procedure. The results suggest that both subtypes of glutamate receptors are regulated in an activity-depe ndent way and that sensory stimulation transiently modifies local cort ical processing. (C) 1996 Academic Press, Inc.