Seol Geun Hee, Ziburkus Jokubas, Huang ShiYong, Song Lihua, Kim In Tae, Takamiya Kogo, Huganir Richard L, Lee Hey-Kyoung, Kirkwood Alfredo
The Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218, USA.
Neuron. 2007 Sep 20;55(6):919-29. doi: 10.1016/j.neuron.2007.08.013.
Near coincidental pre- and postsynaptic action potentials induce associative long-term potentiation (LTP) or long-term depression (LTD), depending on the order of their timing. Here, we show that in visual cortex the rules of this spike-timing-dependent plasticity are not rigid, but shaped by neuromodulator receptors coupled to adenylyl cyclase (AC) and phospholipase C (PLC) signaling cascades. Activation of the AC and PLC cascades results in phosphorylation of postsynaptic glutamate receptors at sites that serve as specific "tags" for LTP and LTD. As a consequence, the outcome (i.e., whether LTP or LTD) of a given pattern of pre- and postsynaptic firing depends not only on the order of the timing, but also on the relative activation of neuromodulator receptors coupled to AC and PLC. These findings indicate that cholinergic and adrenergic neuromodulation associated with the behavioral state of the animal can control the gating and the polarity of cortical plasticity.
近乎同时发生的突触前和突触后动作电位会诱导关联性长期增强（LTP）或长期抑制（LTD），这取决于它们的时间顺序。在此，我们表明在视觉皮层中，这种依赖于尖峰时间的可塑性规则并非一成不变，而是由与腺苷酸环化酶（AC）和磷脂酶C（PLC）信号级联相关的神经调质受体塑造。AC和PLC级联的激活导致突触后谷氨酸受体在作为LTP和LTD特定“标签”的位点发生磷酸化。因此，给定的突触前和突触后放电模式的结果（即LTP还是LTD）不仅取决于时间顺序，还取决于与AC和PLC相关的神经调质受体的相对激活。这些发现表明，与动物行为状态相关的胆碱能和肾上腺素能神经调节可以控制皮层可塑性的门控和极性。
