TMT, an organotin compound, is known to cause selective cell damage in the rat hippocampal CA3 region.Adrenalectomy (ADX) increased TMT-induced apoptosis in CA3 and dentate gyrus (DG) regions (2000 SFN Abstract 121.6). In the present study, we evaluated the temporal and spatial course of both apoptosis and neurogenesis in TMT-treated rats. Male adult SD rats were assigned as follows: control, TMT, ADX and TMT + ADX. Rats were killed on 1,2,3,5,7 days after TMT reatment, and 24 hours before sacrifice, they were received bromodeoxyuridine (BrdU; 50 mg/kg). In TMT rats, apoptotic cells were found in DG granular cells and in CA3 pyramidal cells as early as day 1 and then gradually increased. BrdU labeled cells, which appeared later than apoptotsis, were found to scatter in the hilus and around the pyramidal cell layer, but not within the pyramidal cell layer. Though ADX virtually had no effects on neurogenesis, the same treatment obviously aggravated both TMT-induced apoptosis and neurogenesis in the hippocamp...