TRIMETHYLTIN-INDUCED LOSS OF NMDA AND KAINATE RECEPTORS IN THE RAT-BRAIN

Adult rats exposed acutely to trimethyltin (TMT) manifest a number of behavioral alterations, in conjunction with neuronal degeneration in t he limbic system. In the present study, changes in H-3-TCP binding to N-methyl-D-aspartate (NMDA) receptors and H-3-kainic acid (KA) binding to kainate receptors were studied by autoradiographic methods followi ng TMT exposure (8 mg/kg, i.p.) in adult Sprague Dawley rats. No signi ficant alterations were found at 4 hours after exposure. An extensive loss of H-3-TCP and H-3-KA binding was seen in the hilar region of the CA3 field at 2 and 12 weeks after TMT exposure. Also, the H-3-TCP bin ding was decreased in piriform cortex and in striatum. Thus, TMT expos ure leads to a major and regional selective loss of NMDA and kainate r eceptors in the limbic system, alterations that may be involved in the neuropathology and behavioral sequelae of TMT toxicity.