Trimethyltin-induced loss of NMDA and kainate receptors in the rat brain

Summary Adult rats exposed acutely to trimethyltin (TMT) manifest a number of behavioral alterations, in conjunction with neuronal degeneration in the limbic system. In the present study, changes in³H-TCP binding to N-methyl-D-aspartate (NMDA) receptors and³H-kainic acid (KA) binding to kainate receptors were studied by autoradiographic methods following TMT exposure (8 mg/kg, i.p.) in adult Sprague Dawley rats. No significant alterations were found at 4 hours after exposure. An extensive loss of³H-TCP and³H-KA binding was seen in the hilar region of the CA3 field at 2 and 12 weeks after TMT exposure. Also, the³H-TCP binding was decreased in piriform cortex and in striatum. Thus, TMT exposure leads to a major and regional selective loss of NMDA and kainate receptors in the limbic system, alterations that may be involved in the neuropathology and behavioral sequelae of TMT toxicity.Abbreviations TMT trimethyltin - NMDA N-methyl-D-aspartate - KA Kainic acid - TCP N-(1-2-thienylcyclohexyl)-3,4-piperidine