van Vreeswijk C, Sompolinsky H
Racah Institute of Physics and Center for Neural Computation, Hebrew University, Jerusalem, 91904 Israel.
Science. 1996 Dec 6;274(5293):1724-6. doi: 10.1126/science.274.5293.1724.
Neurons in the cortex of behaving animals show temporally irregular spiking patterns. The origin of this irregularity and its implications for neural processing are unknown. The hypothesis that the temporal variability in the firing of a neuron results from an approximate balance between its excitatory and inhibitory inputs was investigated theoretically. Such a balance emerges naturally in large networks of excitatory and inhibitory neuronal populations that are sparsely connected by relatively strong synapses. The resulting state is characterized by strongly chaotic dynamics, even when the external inputs to the network are constant in time. Such a network exhibits a linear response, despite the highly nonlinear dynamics of single neurons, and reacts to changing external stimuli on time scales much smaller than the integration time constant of a single neuron.
行为动物皮层中的神经元表现出时间上不规则的放电模式。这种不规则性的起源及其对神经处理的影响尚不清楚。从理论上研究了一种假设，即神经元放电的时间变异性源于其兴奋性和抑制性输入之间的近似平衡。在由相对强突触稀疏连接的兴奋性和抑制性神经元群体的大型网络中，这种平衡自然出现。即使网络的外部输入在时间上是恒定的，由此产生的状态也具有强烈的混沌动力学特征。尽管单个神经元具有高度非线性动力学，但这样的网络表现出线性响应，并且在比单个神经元的积分时间常数小得多的时间尺度上对变化的外部刺激做出反应。
