The Scopolamine-Induced Impairment of Spatial Cognition Parallels the Acetylcholine Release in the Ventral Hippocampus in Rats

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Author(s)

Abstract

We investigated the relationship between the induction of spatial cognition impairment in the 8−arm radial maze task and regional changes(ventral hippocampus(VH), dorsal hippocampus, frontal cortex, and basolateral amygdala nucleus)in brain acetylcholine(ACh)release using microdialysis in rats treated with muscarinic(M)receptor antagonists.In a behavioral study, two M<SUB>1</SUB> antagonists, scopolamine(0.5 mg/kg, i.p.and 20 μg, i.c.v.)and pirenzepine(80 μg, i.c.v.), but not an M<SUB>2</SUB> antagonist, AF−DX116(40−80 μg, i.c.v.), disrupted spatial cognition in the 8−arm radial maze task.In brain microdialysis with Ringer’s solution containing 0.1 mM eserine sulfate, scopolamine and AF−DX116, but not pirenzepine, increased ACh release in the VH.Moreover, in the bilateral injection of scopolamine(2 μg/side), the VH and dorsomedial thalamus nucleus were important regions for scopolamine−induced impairment of spatial cognition.A simultaneous determination of the behavioral changes revealed that scopolamine(0.5 mg/kg, i.p.)markedly decreased the ACh contents and also increased the ACh release in all regions tested.Especially, the changes in the ACh release of the VH closely paralleled the induction of the scopolamine−induced impairment of spatial cognition.These results suggest that the blocking balance between M<SUB>1</SUB> and M<SUB>2</SUB> muscarinic receptor in the VH therefore plays a major role in the spatial cognition impairment induced by scopolamine in the 8−arm radial maze task.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 84(2), 163-173, 2000-10-01

    The Japanese Pharmacological Society

References:  36

Cited by:  4

Codes

  • NII Article ID (NAID)
    10008185650
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    00215198
  • NDL Article ID
    5549285
  • NDL Source Classification
    ZS51(科学技術--薬学)
  • NDL Call No.
    Z53-D199
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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