LONG-TERM POTENTIATION OF THE PERFORANT PATH INVIVO IS ASSOCIATED WITH INCREASED GLUTAMATE RELEASE
LONG-TERM POTENTIATION OF THE PERFORANT PATH INVIVO IS ASSOCIATED WITH INCREASED GLUTAMATE RELEASE
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DOI：
10.1038/297496a0
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发表时间：
1982-01-01
期刊：
影响因子：
64.8
通讯作者：
BLISS, TVP
中科院分区：
文献类型：
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作者：
DOLPHIN, AC;ERRINGTON, ML;BLISS, TVP
海马神经通路在短时间高频刺激后突触传递的长时程增强（LTP）作为记忆的一种可能的生理机制而引起人们的关注。LTP的机制还不太清楚，有证据表明突触前和突触后机制都参与其中1 -7。以前的研究结果表明，钙是所需的LTP 8，9，LTP是伴随着一个长期增加的Ca 2+摄取10，表明增加冲动依赖性释放的递质，一个过程严重依赖于突触前Ca 2 + levels 11，12，可能是一个重要组成部分，这种形式的突触可塑性。最近的一项报告13表明，强直刺激海马脑片中的CA 1锥体细胞的传入纤维后，先前积累的3 H-D-天冬氨酸的释放增加，这也与突触前机制一致。然而，一直没有直接的证据表明LTP增加刺激依赖释放的递质。我们现在已经研究了大鼠的执行路径（PP）中的LTP是否与神经递质释放的变化有关。推拉套管技术的改进使我们能够注入3 H-谷氨酰胺并测量随后新合成的3 H-谷氨酸的释放，同时监测刺激PP在齿状回诱发的场电位。我们已经发现了一个长期的增加释放谷氨酸，可能的发射机的PP 14，15，以下诱导LTP在这条途径。
Long-term potentiation (LTP) of synaptic transmission following brief trains of high-frequency stimulation in hippocampal pathways has attracted attention as a possible physiological correlate of memory. The mechanism of LTP is little understood, and what evidence there is suggests that both pre- and postsynaptic mechanisms are involved1–7. Previous findings that Ca2+is required for LTP8,9, and that LTP is accompanied by a prolonged increased in Ca2+uptake10, suggest that an increase in impulse-dependent release of transmitter, a process critically dependent on presynaptic Ca2+levels11,12, may be an important component of this form of synaptic plasticity. A recent report13that release of previously accumulated3H-D-aspartate is increased following tetanic stimulation of afferent fibres to CA1 pyramidal cells in hippocampal slices is also consistent with a presynaptic mechanism. However, there has been no direct evidence relating LTP to an increased stimulus-dependent release of transmitter. We have now investigated whether LTP in the perf orant path (PP) of the rat is associated with a change in the release of neurotransmitter. A modification of the push-pull cannula technique has enabled us to infuse3H-glutamine and measure the subsequent release of newly synthesized3H-glutamate, and at the same time to monitor the field potentials evoked in the dentate gyrus by stimulation of the PP. We have found a prolonged increase in the release of glutamate, the probable transmitter of the PP14,15, following the induction of LTP in this pathway.