Synaptic plasticity in hippocampal CA1 neurons and learning behavior in transient ischemia-loaded gerbils

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Author(s)

    • LI Jianmin
    • Department of Physiology, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan|Department of Neurosurgery, Clinical College of Heibei United University, Tangshan, Hebei, 063000 People's Republic of China
    • SASAKI Hiroshi
    • Department of Physiology, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan|Department of Software Science, Tamagawa University College of Engineering, Machida 194-8610, Japan
    • FUJIWARA Hiroki
    • Department of Physiology, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan
    • KATO Hiroshi
    • Department of Physiology, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan
    • KANEKO Kenya
    • Department of Physiology, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan
    • YAMAZAKI Yoshihiko
    • Department of Physiology, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan
    • FUJII Satoshi
    • Department of Physiology, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan

Abstract

We studied the synaptic plasticity of hippocampal CA1 neurons and spatial learning behavior in gerbils that had been loaded with a transient cerebral ischemia caused by 5 min or 10 min occlusion of the bilateral carotid arteries. The stimulus threshold to elicit the field responses after a transient cerebral ischemia was not different from that in controls, but there was a significant decrease in the magnitude of synaptic responses, which might result from the observed loss of neurons. Long-term potentiation (LTP) and depotentiation after a 10 min cerebral ischemia expressed as a percentage of the pre-tetanus or pre-low frequency stimulation value were almost the same as those in controls, although the actual magnitude of the LTP and depotentiation was lower than in controls. Gerbils that were loaded with a 10 min cerebral ischemia showed impairment in a spatial learning test when this was started 10 days after the cerebral ischemia, but not when it was started 20 days after the same cerebral ischemia. These results suggest that the changes in electrophysiological properties of hippocampal CA1 neurons seen at 10 days after a 10 min cerebral ischemia contribute to the impairment of spatial learning of gerbils seen at this time, and that the extra-CA1 regions might be involved in the recovery of spatial learning seen at 20 days after cerebral ischemia.

Journal

  • Biomedical Research

    Biomedical Research 34(2), 75-85, 2013

    Biomedical Research Press

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