Experience-dependent intrinsic plasticity in interneurons of barrel cortex layer IV.
Experience-dependent intrinsic plasticity in interneurons of barrel cortex layer IV.
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DOI：
10.1152/jn.00562.2009
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发表时间：
2009-09
影响因子：
2.5
通讯作者：
Qian-Quan Sun
中科院分区：
文献类型：
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作者：
Qian-Quan Sun
目前还不清楚特定中间神经元的内在兴奋性是否受到感觉经验的调节。在这里，我研究了GAD 67-GFP小鼠的“感觉保留”和“感觉剥夺”皮质中中间神经元的内在兴奋性。结果表明，胡须修剪，在出生后7天开始3周，诱导的内在和发射特性的快速尖峰（FS），但不定期尖峰非锥体（RSNP）细胞的显着变化。感觉剥夺可显著改变FS细胞的放电阈值、锋电位频率、锋电位适应指数和输入电阻，使FS细胞变得不那么兴奋。FS细胞中IA电流的上调似乎是负责的。沿着FS细胞内在特性的改变，胡须修剪也诱导了“感觉剥夺桶”中FS细胞囊泡谷氨酸转运体2阳性静脉曲张和小清蛋白表达的数量以及丘脑皮质（TC）兴奋性突触后电流的强度的显著减少。“TC刺激引起的尖峰诱导的概率降低了30%，并且在感觉剥夺的FS细胞中尖峰抖动增加。这些结果表明，FS网络被选择性抑制的感觉剥夺。FS，但不是RSNP细胞与TC突触的内在特性和小白蛋白的表达的同时变化支持TC通路和谷氨酸对桶皮质中抑制性网络的感觉诱导的活性依赖性内在可塑性的贡献。
It is unclear whether intrinsic excitabilities of specific interneurons are modulated by sensory experiences. Here, I examined the intrinsic excitabilities of interneurons in "sensory-spared" and "sensory-deprived" cortices of GAD67-GFP mice. The results showed that whisker trimming, begun at postnatal day 7 for 3 wk, induced significant changes in intrinsic and firing properties of fast-spiking (FS) but not regular spiking nonpyramidal (RSNP) cells. Firing threshold, spike frequency, spike adaptation index, and input resistance of FS cells were significantly altered by sensory deprivation such that FS cells became less excitable. An up-regulation of IA currents in FS cells appeared to be responsible. Along with changes in the intrinsic properties of FS cells, whisker trimming also induced a robust reduction in the number of vesicular glutamate transporter 2 positive varicosities and parvalbumin expression and the strength of thalamocortical (TC) excitatory postsynaptic currents in FS cells in the "sensory-deprived barrels." The probability of spike induction by TC stimulus was reduced by 30% and the spike jitter was increased in sensory-deprived FS cells. These results suggest that the FS networks are selectively inhibited by sensory deprivation. The concurrent changes of intrinsic properties and expression of parvalbumin in FS but not RSNP cells with TC synapses support a contribution from the TC pathway and glutamate to sensory-induced activity-dependent intrinsic plasticity of inhibitory networks in barrel cortex.