碩士 / 國立臺灣大學 / 心理學系 / 82 / Hippocampal long-term potentiation (LTP) is a widely recog
-nized model system for studying basic mechanisms of learning
and memory. Its induction requires transient activation of
postsynaptically located NMDA receptors, whereas its expression
requires activation of AMPA receptors. Hippocampus plays an
essential role in spatial learning and memory, it is reasonable
to test whether hippocampal NMDA and AMPA receptors are
involved in the acquisition and retrieval of spatial memory.
Pre-training injection of an NMDA receptors antagonist APV
directly into the hippocampus impaired learning of the Morris
water maze. However, post-training injection spared this
learning ability. Pre-test application of APV did not impair
the retrieval of well-formed memory. These results suggest that
hippocampal NMDA receptors are involved in the early stage of
memory acquisition, but not retrieval of well-learned memory.
The AMPA receptor antagonist CNQX impaired acquisition of
spatial memory in the same manner as APV. Such an effect might
be due to that CNQX blocks the depolarization required for
opening NMDA channels. Pretest application of 0.3 or 1.0.um.g
CNQX caused significant retrieval deficits. This deficit was
restricted to the first trial of the four-trial test. Such a
finding suggests that CNQX can only block retrieval of long
term memory, but has no significant effects on short term or
working memory.The first-trial CNQX blocking effect could be
completely abolished by reminding the animal with an experience
of standing on the platform or stress in the water. Thus, water
maze learning might involve both spatial and emotional
attributes. Finally, pre-test injection of lidocaine into the
hippocampus had the same effect as CNQX, this finding suggests
that the hippocampus might not be the only locus where long
term spatial memory resides.
| Identifer | oai:union.ndltd.org:TW/082NTU00071009 |
| Date | January 1994 |
| Creators | Hon,Wai, 韓衛 |
| Contributors | Liang,K.C., 梁庚辰 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 90 |
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