Rapid changes in thalamic firing synchrony during repetitive whisker stimulation.
Rapid changes in thalamic firing synchrony during repetitive whisker stimulation.
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DOI：
10.1523/jneurosci.1586-08.2008
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发表时间：
2008-10-29
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影响因子：
--
通讯作者：
Simons DJ
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文献类型：
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作者：
Temereanca S;Brown EN;Simons DJ
丘脑放电同步被认为是通过使受体皮层神经元对时间相关的输入尖峰更敏感来确保相关感觉信息向受体皮层神经元的选择性传输。然而，丘脑中同步代码的直接证据是有限的。在这里，我们使用大鼠体感须/桶系统中单个丘脑桶状体的同时单单位记录，直接测量丘脑放电同步性及其随时间的刺激诱导调制。采用晶须偏转速度或频率和互相关的方法不同，我们发现系统的变化，在时间过程和强度的丘脑放电同步作为刺激参数和感觉适应的函数。同步性发展得更快，速度偏转越大，同步性就越强。更大的放电同步性反映了瞬时放电率的刺激依赖性增加，相对于刺激起始的更大的尖峰时间精度以及可能来自发散的三叉神经丘脑和皮质丘脑神经元的共同输入。随着适应，同步性降低，需要更长的时间来发展，但更依赖于细胞的共同输入。快速，急剧增加丘脑同步镜像快速增加晶须速度也发生在正在进行的随机，高频晶须振动。总之，结果表明，在复杂的模式，正在进行的触须运动，可以确保在搅拌和主动触摸过程中的本地丘脑皮层电路的首选感觉信息的传输在丘脑近同步发射毫秒的变化。
Thalamic firing synchrony is thought to ensure selective transmission of relevant sensory information to the recipient cortical neurons by rendering them more responsive to temporally correlated input spikes. However, direct evidence for a synchrony code in the thalamus is limited. Here, we directly measure thalamic firing synchrony and its stimulus-induced modulation over time, using simultaneous single unit recordings from individual thalamic barreloids in the rat somatosensory whisker/barrel system. Employing whisker deflections varying in velocity or frequency and a cross-correlation approach, we find systematic changes in both time-course and strength of thalamic firing synchrony as a function of stimulus parameters and sensory adaptation. Synchrony develops faster and is greater with higher velocity deflections. Greater firing synchrony reflects stimulus-dependent increases in instantaneous firing rates, greater spike time precision relative to stimulus onset as well as common input that likely arises from divergent trigeminothalamic and corticothalamic neurons. With adaptation, synchrony decreases and takes longer to develop but is more dependent on the cells’ common inputs. Rapid, sharp increases in thalamic synchrony mirroring quick increases in whisker velocity occur also during ongoing random, high-frequency whisker vibrations. Together, results demonstrate millisecond by millisecond changes in thalamic near-synchronous firing during complex patterns of ongoing vibrissa movements that may ensure transmission of preferred sensory information in local thalamocortical circuits during whisking and active touch.