title: Postischemic alterations of complex spike cell discharges and evoked potentials in rat hippocampal CA1 region.
abstract: Postischemic alterations of spontaneous discharges of complex spike cells (CS cells) and evoked potential in the rat hippocampal CA1 region were studied. Following 5 min of ischemia, CS cell discharge reappeared approximately 5 min after reperfusion and the frequency remained low, reaching a final value of 66.1 +/- 16.0% (n = 11) of preischemic frequency 2 h later. However, only one of 7 CS cells subjected to 20 min of ischemia exhibited discharges 2 h later. In the group with 5 min of ischemia, we obtained CS cell discharges from all rats at both 1 and 2 days after ischemia, with cluster frequencies indistinguishable from preischemic levels. In the group with 20 min of ischemia, discharges were noted in 7 neurons of 11 rats after 1 day, and in only 2 neurons of 8 rats after 2 days: their mean frequencies were lower than preischemic levels. In experiments of evoked potentials, the mean percentages of amplitudes of the post-synaptic potential (psp) 2 h after 3, 5 and 20 min of ischemia were 98.0 +/- 10.7 (n = 8), 70.7 +/- 8.22 (n = 9) and 45.1 +/- 6.34% (n = 7) of preischemic amplitudes, respectively. These results suggest that the functional deterioration of spike generation, as well as synaptic transmission, starts during transient ischemia and/or at the early stage of reperfusion.
authors.affiliation: Department of Neurology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Furukawa
authors.forename: K
authors.initials: K
authors.lastname: Yamana
authors.forename: K
authors.initials: K
authors.lastname: Kogure
mesh_terms: D000818:Animals; D001931:Brain Mapping; D004558:Electric Stimulation; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D002546:Ischemic Attack, Transient / Q000503:physiopathology*; D008297:Male; D009474:Neurons / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology*