Synchronization in networks of excitatory and inhibitory neurons with sparse, random connectivity
Synchronization in networks of excitatory and inhibitory neurons with sparse, random connectivity
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DOI：
10.1162/089976603321192059
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发表时间：
2003-03-01
影响因子：
2.9
通讯作者：
Kopell, N
中科院分区：
文献类型：
--
作者：
Börgers, C;Kopell, N
在模型网络和I细胞的模型网络（分别分别兴奋性和抑制神经元）中，同步节奏峰通常来自两个细胞组之间的相互作用：E-Cells同步I-Cells I-Cells，而VICE反之亦然。在理想的条件下，相关网络参数和全能连接的同质性，例如，这种机制可以产生完美的同步。我们发现，即使使用非常稀疏的随机连接，也可能实现近似，不完美的同步。关键数量是每个单元的预期输入数量。只要它足够大（更确切地说，只要每个细胞的突触输入总数的方差足够小），就可以进行紧密的同步。可以通过增强E-> i突触来降低随机连通性的非同步效应。更令人惊讶的是，无法通过加强I-> e突触来减少它。但是，抑制的衰减时间常数起重要作用。更快的衰减会产生更严格的同步。特别是，在假定抑制性突触是瞬时的模型中，无法看到稀疏，随机连通性的影响。
In model networks of E-cells and I-cells (excitatory and inhibitory neurons, respectively), synchronous rhythmic spiking often comes about from the interplay between the two cell groups: the E-cells synchronize the I-cells and vice versa. Under ideal conditions-homogeneity in relevant network parameters and all-to-all connectivity, for instance-this mechanism can yield perfect synchronization. We find that approximate, imperfect synchronization is possible even with very sparse, random connectivity. The crucial quantity is the expected number of inputs per cell. As long as it is large enough (more precisely, as long as the variance of the total number of synaptic inputs per cell is small enough), tight synchronization is possible. The desynchronizing effect of random connectivity can be reduced by strengthening the E-->I synapses. More surprising, it cannot be reduced by strengthening the I-->E synapses. However, the decay time constant of inhibition plays an important role. Faster decay yields tighter synchrony. In particular, in models in which the inhibitory synapses are assumed to be instantaneous, the effects of sparse, random connectivity cannot be seen.