title: A brief brain ischemia produces morphological damage of hippocampal CA1 pyramidal cells without affecting the sensitivities of psychoactive drugs in two types of discrete avoidance tasks in Mongolian gerbils.
abstract: Effects of subcutaneous administration of psychoactive drugs: methamphetamine (0.13-1 mg/kg), chlorpromazine (0.5-2 mg/kg), physostigmine (0.05-0.2 mg/kg), scopolamine (0.031-0.5 mg/kg), pentobarbital (5-20 mg/kg), diazepam (0.5-2 mg/kg) and morphine (1.3-5 mg/kg) on discrete lever-press and shuttle avoidance responses were investigated in Mongolian gerbils that had received a brief (5 min) bilateral brain ischemic operation. Although some of the ischemic animals tended to show a retardation of acquisition of the avoidance responses, the established baselines were almost identical between the sham-operated and ischemic groups. In the lever-press task, morphine increased the response rate, whereas chlorpromazine, physostigmine, pentobarbital and diazepam decreased both the response and avoidance rates in a dose-dependent manner. In the shuttle avoidance task, both the response and avoidance rates were dose-dependently increased by methamphetamine, scopolamine and morphine, but chlorpromazine, physostigmine, pentobarbital and diazepam dose-dependently decreased them. These drug effects were almost the same between the sham-operated and ischemic groups. However, the ischemic-operation produced a significant loss of pyramidal cells in the CA1 sector of the hippocampus, the remaining level being less than 10% that of the sham-operated control animals.
authors.affiliation: Behavior Research Institute, Gunma University School of Medicine, Maebashi, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Umezu
authors.forename: H
authors.initials: H
authors.lastname: Kuribara
authors.forename: K
authors.initials: K
authors.lastname: Hirate
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.forename: S
authors.initials: S
authors.lastname: Tadokoro
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D002545:Brain Ischemia / Q000473:pathology / Q000503:physiopathology*; D004305:Dose-Response Relationship, Drug; D005849:Gerbillinae; D006624:Hippocampus / Q000166:cytology / Q000473:pathology*; D008297:Male; D011619:Psychotropic Drugs / Q000494:pharmacology*; D011712:Pyramidal Tracts / Q000166:cytology / Q000473:pathology*
chemical_list: D011619:Psychotropic Drugs