Electrical synapses in the thalamic reticular nucleus
Electrical synapses in the thalamic reticular nucleus
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DOI：
10.1523/jneurosci.22-03-01002.2002
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发表时间：
2002-02-01
影响因子：
5.3
通讯作者：
Connors, BW
中科院分区：
文献类型：
--
作者：
Landisman, CE;Long, MA;Connors, BW
丘脑网状核（TRN）的神经元向丘脑中继细胞提供抑制性输入，并在睡眠和癫痫发作期间产生同步活动。人们普遍认为TRN细胞仅通过化学突触连接相互作用。然而，我们发现，在大鼠和小鼠中，许多相邻的TRN神经元对是电耦合的。在成对细胞记录中，当耦合强度很强时，电突触能够介导动作电位之间的密切相关性;即使耦合强度较低，它们也可以调节爆发性放电状态。TRN神经元之间的电突触在连接蛋白36（Cx 36）基因无效突变的小鼠中不存在。令人惊讶的是，没有观察到抑制性化学突触对神经元之间的连接，虽然强烈的细胞外刺激可以引起抑制在单个TRN神经元。我们的结论是Cx 36依赖的间隙连接在TRN内的神经放电模式的调节中发挥重要作用。当结合最近从大脑皮层的观察，我们的研究结果表明，电突触是一种常见的机制，在哺乳动物前脑的抑制性神经元网络内产生同步。
Neurons of the thalamic reticular nucleus (TRN) provide inhibitory input to thalamic relay cells and generate synchronized activity during sleep and seizures. It is widely assumed that TRN cells interact only via chemical synaptic connections. However, we show that many neighboring pairs of TRN neurons in rats and mice are electrically coupled. In paired-cell recordings, electrical synapses were able to mediate close correlations between action potentials when the coupling was strong; they could modulate burst-firing states even when the coupling strength was more modest. Electrical synapses between TRN neurons were absent in mice with a null mutation for the connexin36 (Cx36) gene. Surprisingly, inhibitory chemical synaptic connections between pairs of neurons were not observed, although strong extracellular stimuli could evoke inhibition in single TRN neurons. We conclude that Cx36-dependent gap junctions play an important role in the regulation of neural firing patterns within the TRN. When combined with recent observations from the cerebral cortex, our results imply that electrical synapses are a common mechanism for generating synchrony within networks of inhibitory neurons in the mammalian forebrain.