Excitatory amino acid receptors in the prefrontal cortex of aging mice

The zones of the prefrontal cortex of Balb/c mice were tested for age-relat ed changes of the ionotropic excitatory amino acid receptors density, toget her with zones of the dorsal cortex. Kainate, N-methyl-D-aspartate, and ami na-3-hydroxy-5-methyloxazole-4-propionate sites were measured by slice rece ptor binding techniques in cortical zones from animals at the age of 6, 12, 18, and 24 months. An increase of the N-methyl-D-aspartate sites was detec ted in the medial prefrontal zone of mid-aged animals and was followed by a decrease at old age; a decrease of the N-methyl-D-aspartate and kainate si tes was found for the medial dorsal (cingulate) cortex at old age. The age- related changes of receptor densities in the different cortical areas seem unrelated in origin. The sites decrease in the cingulate cortex could affec t the transfer of the prefrontal cortex activity toward limbic structures. (C) 2000 Elsevier Science Inc. All rights reserved.