Synaptic depression and cortical gain control
Synaptic depression and cortical gain control
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DOI：
10.1126/science.275.5297.221
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发表时间：
1997-01-10
期刊：
影响因子：
56.9
通讯作者：
Nelson, SB
中科院分区：
文献类型：
--
作者：
Abbott, LF;Varela, JA;Nelson, SB
皮层神经元接受来自数千个传入神经的突触输入，这些传入神经以低于1赫兹到超过200赫兹的速率激发动作电位。传入神经的数量和它们的大动态范围都可以掩盖突触活动的空间和时间模式的变化，限制皮层神经元对其输入做出响应的能力。基于实验测量的建模工作表明，皮质内突触的短期抑郁症提供了一个动态的增益控制机制，允许快速和缓慢发射传入产生相等的突触后反应等百分比的变化。与降低对所有输入的反应性的抑制和适应机制不同，突触抑制是输入特异性的，阅读是神经元对其传入神经放电模式的微妙变化的敏感性急剧增加。
Cortical neurons receive synaptic inputs from thousands of afferents that fire action potentials at rates ranging from less than 1 hertz to more than 200 hertz. Both the number of afferents and their large dynamic range can mask changes in the spatial and temporal pattern of synaptic activity, limiting the ability of a cortical neuron to respond to its inputs. Modeling work based on experimental measurements indicates that short-term depression of intracortical synapses provides a dynamic gain-control mechanism that allows equal percentage rate changes on rapidly and slowly firing afferents to produce equal postsynaptic responses. Unlike inhibitory and adaptive mechanisms that reduce responsiveness to all inputs, synaptic depression is input-specific, reading to a dramatic increase in the sensitivity of a neuron to subtle changes in the firing patterns of its afferents.