Involvement of hippocampal PKCβI isoform in the early phase of memory formation of an inhibitory avoidance learning
Involvement of hippocampal PKCβI isoform in the early phase of memory formation of an inhibitory avoidance learning
复制标题
DOI：
10.1016/s0006-8993(99)02323-9
复制
发表时间：
2000-02-14
期刊：
影响因子：
2.9
通讯作者：
Medina, JH
中科院分区：
文献类型：
--
作者：
Paratcha, G;Furman, M;Medina, JH
大量研究表明，蛋白激酶C（PKC）参与海马长时程增强（LTP）和不同形式的学习，包括大鼠的抑制性回避训练。在这里，我们评估了从接受一次试验抑制性回避范式的大鼠海马中分离的突触质膜（SPM）部分中常规PKC同工酶（α、β I、β II、γ）的水平。在训练后0、30和120分钟，PKC β I的总量显着增加。免疫印迹的密度分析显示，相对于电击对照值，训练后0分钟增加142 +/- 11%，30分钟增加193 +/- 16%，120分钟增加156 +/- 6%。与未处理对照组相比，休克动物SPM组分中PKC β I水平无变化。在检测的任何时间点均未观察到PKC α、β II和γ水平的训练特异性增量。然而，在每次实验程序后120分钟处死的训练和休克动物中发现PKC γ水平增加。此外，双侧微量注射一种相当有选择性的PKC β I同工酶抑制剂到背海马CA 1产生健忘症时，给予训练前10分钟，或50，110，但不是170分钟，训练后。因此，目前的研究结果表明，PKC β I的参与，负责收购和巩固的抑制性回避学习的早期突触事件，并建议一个假定的作用，这种突触前同工酶增强PKC依赖的B-50/GAP-43磷酸化，我们以前检测到在这种联想学习。(C)2000 Elsevier Science B. V.保留所有权利。
Several evidences demonstrate that protein kinase C (PKC) is involved in hippocampal long-term potentiation (LTP) and in different forms of learning, including inhibitory avoidance training in rats. Here, we evaluated the levels of conventional PKC isozymes (alpha, beta I, beta II, gamma) in synaptic plasma membrane (SPM) fractions isolated from hippocampus of rats subjected to a one-trial inhibitory avoidance paradigm, At 0, 30 and 120 min after training, there was a significant increase in the total amount of PKC beta I. Densitometric analysis of the immunoblots showed an increase of 142 +/- 11% at 0 min, 193 +/- 16% at 30 min and 156 +/- 6% at 120 min after training relative to shocked control values. No changes were found in PKC beta I levels in SPM fractions of the shocked animals relative to naive control values. No training-specific increments in the levels of PKC alpha, beta II and gamma were observed at any time point tested. However, an increase in PKC gamma levels was found in trained and shocked animals sacrificed 120 min after each experimental procedure. In addition, bilateral microinjections of a fairly selective inhibitor of PKC beta I isozyme into the CA1 of the dorsal hippocampus produced amnesia when given 10 min before training, or 50, 110, but not 170 min, after training. Thus, the present findings demonstrate the participation of PKC beta I in the early synaptic events responsible for the acquisition and consolidation of an inhibitory avoidance learning, and suggest a putative role of this presynaptic isozyme on the enhanced PKC-dependent B-50/GAP-43 phosphorylation previously detected by us during this associative learning. (C) 2000 Elsevier Science B.V. All rights reserved.