title: Electrophysiological changes in substantia nigra after striatal infarction.
abstract: The GABAergic efferent pathway from the striatum exerts inhibitory control on the substantia nigra pars reticulata (SNR) neurones. We studied sequential changes in spontaneous single-unit activities in the ipsilateral SNR 1 h, 1 day, 7 days and 14 days after striatal infarction induced by middle cerebral artery occlusion (MCAO) in rats. Compared with a sham-operated group, there was no change in the firing rate 1 h after MCAO, and one day after MCAO the mean firing rate decreased. The firing rate of SNR neurones at 7 and 14 days after MCAO was significantly reduced compared with the sham-operated group. Only two neurones (sham-operated group and 1 h after MCAO group) fired with high frequency. Histological examination revealed degeneration of the ipsilateral SNR 7 and 14 days after MCAO. Our results indicated that SNR neuronal degeneration accompanied by striatal ischaemia does not simply depend on hyperexcitation due to the activation of a disinhibition mechanism.
authors: Department of Neurosurgery, Kinki University, Osaka Japan.
authors: T
authors: T
authors: Asai
authors: K
authors: K
authors: Kataoka
authors: T
authors: T
authors: Tokuno
authors: S
authors: S
authors: Chichibu
authors: M
authors: M
authors: Taneda
mesh_terms: D000818:Animals; D002544:Cerebral Infarction / Q000473:pathology / Q000503:physiopathology*; D003250:Constriction; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013378:Substantia Nigra / Q000098:blood supply / Q000166:cytology / Q000503:physiopathology*