Pinsker H M, Kandel E R
Brain Res. 1977 Apr 8;125(1):51-64. doi: 10.1016/0006-8993(77)90359-6.
A presynaptic neuron fires a high-frequency train of spikes that produces long-lasting synaptic inhibition that modulates the bursting rhythm in a small population of endogenous bursting neurons in the left upper quadrant of the isolated abdominal ganglion of Aplysia. Single inputs decrease or increase the duration of the burst cycle as a function of the precise phase of the input (the phase response curve). Two phases of the burst cycle were used to analyze the effects of repeated contingent (phase-locked) stimulation. One contingency involved synaptic input early in the burst cycle that inhibited spikes and decreased the duration, whereas the other contingency involved input late in the cycle that increased the duration. Under both contingencies of stimulation, buildup and short-term persistence were found, however these cumulative effects were not dependent upon the phase of the burst cycle. The locus of the short-term plasticity that underlies the buildup and persistence is in the pacemaker properties of the postsynaptic cell rather than in the synapse. The plastic change appears to involve a nonspecific postinhibitory rebound that follows a single input and builds up with repetition. These results support the suggestion that endogenous rhythms of pacemaker cells can undergo plastic changes and can therefore serve as a means of short-term information storage in the nervous system. However, this neuronal circuit does not have the specificity required to mediate operant conditioning.
突触前神经元发射高频脉冲序列，产生持久的突触抑制，这种抑制调节了海兔离体腹神经节左上象限一小群内源性爆发神经元的爆发节律。单个输入会根据输入的精确相位（相位响应曲线）缩短或延长爆发周期的持续时间。爆发周期的两个阶段被用来分析重复的偶然（锁相）刺激的效果。一种情况是在爆发周期早期的突触输入，它抑制脉冲并缩短持续时间，而另一种情况是在周期后期的输入，它增加持续时间。在两种刺激情况下，都发现了累积和短期持续性，然而这些累积效应并不依赖于爆发周期的相位。构成累积和持续性基础的短期可塑性位点在于突触后细胞的起搏器特性，而非突触。这种可塑性变化似乎涉及单个输入后出现的非特异性抑制后反弹，并随着重复而累积。这些结果支持了以下观点：起搏器细胞的内源性节律可以发生可塑性变化，因此可以作为神经系统中短期信息存储的一种方式。然而，这个神经元回路不具备介导操作性条件反射所需的特异性。
