Ca2+ signaling requirements for long-term depression in the hippocampus
Ca2+ signaling requirements for long-term depression in the hippocampus
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DOI：
10.1016/s0896-6273(00)80102-6
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发表时间：
1996-04-01
期刊：
影响因子：
16.2
通讯作者：
Malenka, RC
中科院分区：
文献类型：
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作者：
Cummings, JA;Mulkey, RM;Malenka, RC
据推测，由突触活动引起的突触重量变化的方向取决于细胞内Ca 2+浓度的活动依赖性上升的幅度。这一假说的几个方面进行了检查，在Schaffer侧支CA 1突触，其中长时程抑制（LTD）和长时程增强（LTP）可以引起和钙依赖。短暂的强直刺激，这通常会产生LTP，可以诱导LTD时，通过NMDA受体的Ca 2+的进入是有限的，无论是由中等浓度的D-APV或电压钳位细胞在负膜电位。在没有传入刺激的情况下，电压依赖性Ca 2+通道的重复激活也可以引起LTD，该LTD是Ca 2+依赖性的，并且通过使用长时间的低频刺激的前一代同突触LTD被闭塞。这些结果提供了强有力的证据表明，诱导LTD的最低要求涉及简单的瞬时流入的Ca 2+到突触后细胞，通过NMDA受体或电压依赖性Ca 2+通道。
It has been hypothesized that the direction of synaptic weight change elicited by synaptic activity depends on the magnitude of the activity-dependent rise in intracellular Ca2+ concentration. Several aspects of this hypothesis were examined at the Schaffer collateral CA1 synapse, where both long-term depression (LTD) and long-term potentiation (LTP) can be elicited and are Ca2+ dependent. Brief tetanic stimulation, which normally generated LTP, could induce LTD when Ca2+ entry via NMDA receptors was limited either by moderate concentrations of D-APV or by voltage clamping cells at negative membrane potentials. Repetitive activation of voltage-dependent Ca2+ channels in the absence of afferent stimulation could also elicit an LTD that was Ca2+ dependent and was occluded by prior generation of homosynaptic LTD using prolonged low frequency stimulation. These results provide strong evidence that the minimal requirements for inducing LTD involve simply a transient influx of Ca2+ into the postsynaptic cell, via either NMDA receptors or voltage-dependent Ca2+ channels.