Active dendritic conductances dynamically regulate GABA release from thalamic Interneurons
Active dendritic conductances dynamically regulate GABA release from thalamic Interneurons
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DOI：
10.1016/j.neuron.2007.12.022
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发表时间：
2008-02-07
期刊：
影响因子：
16.2
通讯作者：
Regehr, Wade G.
中科院分区：
文献类型：
--
作者：
Acuna-Goycolea, Claudio;Brenowitz, Stephan D.;Regehr, Wade G.
抑制性中间神经元在背外侧膝状体核（dLGN）的过程中的视觉信息，精确控制发放时间和通过细化丘脑皮层（TC）神经元的感受野。先前的研究表明，dLGN中间神经元通过从轴突和树突释放GABA来抑制TC神经元。然而，控制GABA释放的机制知之甚少。在这里，使用同时全细胞记录从interneurons和TC神经元和双光子钙成像，我们发现，多个视网膜神经节细胞（RGC）的同步激活触发钠尖峰，传播整个interneurons轴突和树突，和钙尖峰侵入树突，但不是轴突。这些不同的中间神经元放电模式可以触发对TC神经元的快速和持续的抑制成分。我们的研究表明，主动电导使LGN中间神经元灵活的电路元件，可以改变其空间和时间特性的GABA释放响应于功能相关的RGC子集的同时激活。
Inhibitory interneurons in the dorsal lateral geniculate nucleus (dLGN) process visual information by precisely controlling spike timing and by refining the receptive fields of thalamocortical (TC) neurons. Previous studies indicate that dLGN interneurons inhibit TC neurons by releasing GABA from both axons and dendrites. However, the mechanisms controlling GABA release are poorly understood. Here, using simultaneous whole-cell recordings from interneurons and TC neurons and two-photon calcium imaging, we find that synchronous activation of multiple retinal ganglion cells (RGCs) triggers sodium spikes that propagate throughout interneuron axons and dendrites, and calcium spikes that invade dendrites but not axons. These distinct modes of interneuron firing can trigger both a rapid and a sustained component of inhibition onto TC neurons. Our studies suggest that active conductances make LGN interneurons flexible circuit-elements that can shift their spatial and temporal properties of GABA release in response to coincident activation of functionally related subsets of RGCs.