Local dendrodendritic inhibition regulates fast synaptic transmission in visual thalamus.
Local dendrodendritic inhibition regulates fast synaptic transmission in visual thalamus.
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DOI：
10.1523/jneurosci.4402-11.2012
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发表时间：
2012-02-15
期刊：
影响因子：
--
通讯作者：
Cox CL
中科院分区：
文献类型：
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作者：
Crandall SR;Cox CL
丘脑中间神经元的抑制在调节丘脑和新皮层之间的信息传递中起着关键作用。有趣的是，这些神经元通过两种不同的输出产生抑制：支配丘脑皮质中继神经元的突触前树突和轴突输出。由于丘脑中间神经元的树突是传入突触信息的主要目标，因此已经假设局部突触输入可以产生高度集中的树突输出。为了获得额外的洞察力，这些突触前树突的计算能力，我们结合了双光子激光扫描显微镜，谷氨酸uncaging，和全细胞电生理记录，以局部激活树突状终端和研究其抑制大鼠丘脑皮层中继神经元的贡献。我们的研究结果表明，从丘脑中间神经元的局部树突状细胞的释放是由AMPA/NMDA受体介导的L-型钙通道的募集局部控制。此外，通过映射这些连接与单树突分辨率，我们不仅发现，突触前树突优先目标近端区域，但这种行动显着不同的分支。此外，局部刺激的中间神经元树突没有导致全局兴奋，支持的概念，这些中间神经元可以作为多路复用器，包含许多独立操作的输入输出设备。
Inhibition from thalamic interneurons plays a critical role in modulating information transfer between thalamus and neocortex. Interestingly, these neurons yield inhibition via two distinct outputs: presynaptic dendrites that innervate thalamocortical relay neurons and axonal outputs. Since the dendrites of thalamic interneurons are the primary targets of incoming synaptic information, it has been hypothesized that local synaptic input could produce highly focused dendritic output. To gain additional insight to the computational power of these presynaptic dendrites, we have combined two-photon laser scanning microscopy, glutamate uncaging, and whole-cell electrophysiological recordings in order to locally activate dendritic terminals and study their inhibitory contribution onto rat thalamocortical relay neurons. Our findings demonstrate that local dendritic release from thalamic interneurons is controlled locally by AMPA/NMDA receptor-mediated recruitment of L-type calcium channels. Moreover, by mapping these connections with single-dendrite resolution we not only found that presynaptic dendrites preferentially target proximal regions, but such actions differ significantly across branches. Furthermore, local stimulation of interneuron dendrites did not result in global excitation, supporting the notion that these interneurons can operate as multiplexors, containing numerous independently operating input-output devices.