Chronic methamphetamine administration inhibits cerebral ischemia-induced hyperactivity in Mongolian gerbils

The effect of single and chronic methamphetamine (MAP) administration on is chemia-induced hyperactivity was investigated and the mechanism of ischemia -induced hyperactivity was discussed. Ischemia-induced hyperactivity was re cognized 3 h after ischemia. However, ischemia-induced hyperactivity at I d ay after ischemia was inhibited when MAP, in a dose of 10 mg/kg, was admini stered for 7 days and withdrawn for 7 days. It was reported that MAP treatm ent caused an irreversible decrease in the number of dopamine (DA) uptake s ites. In addition to this, monoamine oxidase and the uptake of DA into the nerve terminals are disturbed by cerebral ischemia. Therefore, a lot of DA release happened during and immediately after ischemia, and a marked down-r egulation of DA receptor occurred 24 h after ischemia in MAP-injected group . It is conceivable that the DA receptor, especially the presynaptic DA upt ake site, is related to the occurrence of ischemia-induced hyperactivity. F urther studies appear to be necessary to clarify acceptor susceptibility wh en neurotransmitters are normalized after transient ischemia. (C) 2001 Else vier Science Inc. All rights reserved.