Synaptic modulation of the interspike interval signatures of bursting pyloric neurons.
Synaptic modulation of the interspike interval signatures of bursting pyloric neurons.
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DOI：
10.1152/jn.00732.2002
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发表时间：
2003-03
影响因子：
2.5
通讯作者：
A. Szűcs;R. D. Pinto;M. I. Rabinovich;H. Abarbanel;A. Selverston
中科院分区：
文献类型：
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作者：
A. Szűcs;R. D. Pinto;M. I. Rabinovich;H. Abarbanel;A. Selverston
龙虾胃神经系统的幽门网络是产生动作电位爆发的振荡神经元的最好描述的组件之一。虽然已经详细研究了脉冲串的时间模式，但尖峰脉冲的时间模式受到的关注较少。在这里，我们分析了幽门神经元的爆发内放电模式和突触相互作用，在毫秒级的时间尺度上塑造他们的动力学之前没有执行。我们发现，不同的幽门神经元表达特征，细胞特异性的放电模式，在其爆发。的interspike间隔（ISI）的非线性分析揭示了独特的时间结构（“interspike间隔签名”），这被发现依赖于网络的突触连接。我们比较了ISI模式的幽门扩张（PD），侧幽门（LP），和心室扩张（VD）神经元在1）正常条件下，2）阻断后的突触连接，和3）在各种功能配置的三个神经元。突触连接的操纵导致突触后神经元的ISI签名的特征变化。PD神经元的爆发内放电模式由LP神经元的抑制性突触连接来调节，如电流钳实验中所揭示的，也如用动态钳重建的。另一方面，LP和VD神经元之间的相互抑制往往会产生更多的不规则爆发，增加尖峰抖动。结果表明，突触的相互作用微调幽门神经元的输出。目前的数据还表明了一种处理突触信息的方式：爆发神经元能够通过改变其爆发内尖峰模式的精细结构来编码传入信号。
The pyloric network of the lobster stomatogastric nervous system is one of the best described assemblies of oscillatory neurons producing bursts of action potentials. While the temporal patterns of bursts have been investigated in detail, those of spikes have received less attention. Here we analyze the intraburst firing patterns of pyloric neurons and the synaptic interactions shaping their dynamics in millisecond time scales not performed before. We find that different pyloric neurons express characteristic, cell-specific firing patterns in their bursts. Nonlinear analysis of the interspike intervals (ISIs) reveals distinctive temporal structures ('interspike interval signatures'), which are found to depend on the synaptic connectivity of the network. We compare ISI patterns of the pyloric dilator (PD), lateral pyloric (LP), and ventricular dilator (VD) neurons in 1) normal conditions, 2) after blocking glutamatergic synaptic connections, and 3) in various functional configurations of the three neurons. Manipulation of the synaptic connectivity results in characteristic changes in the ISI signatures of the postsynaptic neurons. The intraburst firing pattern of the PD neuron is regularized by the inhibitory synaptic connection from the LP neuron as revealed in current-clamp experiments and also as reconstructed with a dynamic clamp. On the other hand, mutual inhibition between the LP and VD neurons tend to produce more irregular bursts with increased spike jitter. The results show that synaptic interactions fine-tune the output of pyloric neurons. The present data also suggest a way of processing of synaptic information: bursting neurons are capable of encoding incoming signals by altering the fine structure of their intraburst spike patterns.