Effects of YM872 on atrophy of substantia nigra reticulata after focal ischemia in rats

MIDDLE cerebral artery (MCA) occlusion causes atrophy in the ipsilateral su bstantia nigra reticulata (SNR). The effects of glutamate AMPA receptor ant agonism on SNR atrophy, which is supposed to inhibit excitatory inputs from the subthalamic nucleus to the SNR, was investigated in rats with permanen t MCA occlusions. Histological examination revealed marked atrophy two week s after MCA occlusion in the saline-treated control group. However, constan t i.v. infusion of YM872, a selective AMPA receptor antagonist, for 2 weeks significantly reduced SNR atrophy; neurological deficits also decreased. T hese results suggest that the AMPA receptor may be involved in the pathogen esis of SNR atrophy during the subacute phase of focal cerebral ischemia. N euroReport 9: 3719-3724 (C) 1998 Lippincott Williams & Wilkins.