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ID 30989
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Author
Taniike, Naoki
Lu, Yun-Fei
Tomizawa, Kazuhito
Abstract

The induction of both long-term potentiation (LTP) and long-term depression (LTD) in the hippocampal CA1 region is triggered by the activation of N-methyl-D-aspartate (NMDA) receptors and the subsequent postsynaptic intracellular Ca2+ increase. However, how NMDA receptor activation differs between LTP and LTD induction is unclear. In the present study, we examined the eff ects of the magnitude and duration of NMDA receptor activation on the induction of LTP and LTD. Partial blockage of NMDA receptors by a low concentration of aminophosphonovaleric acid (APV)(2 μM) prevented the induction of LTP, but not LTD. In contrast, a high concentration of APV(25 μM) blocked both LTP and LTD. Tetanus stimulation-induced LTP was impaired when hippocampal slices were given the tetanus stimulation for more than 5 min. Under partial blockage of NMDA receptors, the prolonged-tetanus stimulation induced LTD but not LTP. This phenomenon was mimicked by the application of glutamate to the slices. Finally, LTD induced by prolonged activation of NMDA receptors was not aff ected by inhibition of the desensitization of α-amino-3-hydroxy-5 methylisoxazole-4-propionic acid (AMPA) receptors. These results suggest that critical diff erences exist between the induction of LTP and that of LTD in terms of both the magnitude and the duration of NMDA receptor activation. The duration of the increase in intracellular Ca2+ concentration may be critical for determining whether LTP or LTD induction occurs.

Keywords
LTP
LTD
NMDA receptor
learning and memory
hippocampus
Amo Type
Original Article
Published Date
2008-02
Publication Title
Acta Medica Okayama
Volume
volume62
Issue
issue1
Publisher
Okayama University Medical School
Start Page
21
End Page
28
ISSN
0386-300X
NCID
AA00508441
Content Type
Journal Article
language
英語
File Version
publisher
Refereed
True
PubMed ID
Web of Science KeyUT