Self-regulation of adult thalamocortical neurons.
Self-regulation of adult thalamocortical neurons.
复制标题
成人丘脑皮质神经元的自我调节。
DOI：
10.1152/jn.00800.2014
复制
发表时间：
2015
影响因子：
2.5
通讯作者：
Anderson,MatthewP
中科院分区：
文献类型：
--
作者：
Kasten,MichaelR;Anderson,MatthewP
丘脑是感觉和其他信息传递到大脑皮层的通道。在体内连续感觉刺激时，丘脑皮层神经元的放电频率最初增加，但随后在1分钟内放电频率降低，并出现T型Ca 2+通道依赖的动作电位爆发放电。虽然神经调节系统可以在这种抑制反应中发挥作用，但我们报告了一种新的丘脑中继神经元固有的细胞自主抑制机制。直接细胞内刺激丘脑皮层神经元放电最初触发了连续和高速率的动作电位放电，但在一分钟内膜电位（Vm）超极化和放电率相同的刺激降低。在各种各样的丘脑核团中观察到这种自我抑制，并且在一个子集中，放电模式从紧张转换为爆发。自抑制抵抗细胞内Ca 2+信号传导，Na+-K+-ATP酶，和G蛋白调节的内向整流（GIRK）通道的阻滞剂，在其他神经元亚型牵连，而是部分抑制ATP敏感的K+通道阻滞剂。结果确定了一种新的稳态机制，能够在单细胞水平上门控兴奋信号的丘脑。
The thalamus acts as a conduit for sensory and other information traveling to the cortex. In response to continuous sensory stimulation in vivo, the firing rate of thalamocortical neurons initially increases, but then within a minute firing rate decreases and T-type Ca2+channel-dependent action potential burst firing emerges. While neuromodulatory systems could play a role in this inhibitory response, we instead report a novel and cell-autonomous inhibitory mechanism intrinsic to the thalamic relay neuron. Direct intracellular stimulation of thalamocortical neuron firing initially triggered a continuous and high rate of action potential discharge, but within a minute membrane potential (Vm) was hyperpolarized and firing rate to the same stimulus was decreased. This self-inhibition was observed across a wide variety of thalamic nuclei, and in a subset firing mode switched from tonic to bursting. The self-inhibition resisted blockers of intracellular Ca2+signaling, Na+-K+-ATPases, and G protein-regulated inward rectifier (GIRK) channels as implicated in other neuron subtypes, but instead was in part inhibited by an ATP-sensitive K+channel blocker. The results identify a new homeostatic mechanism within the thalamus capable of gating excitatory signals at the single-cell level.