Stimulus-Specific and Stimulus-Nonspecific Firing Synchrony and Its Modulation by Sensory Adaptation in the Whisker-to-Barrel Pathway
Stimulus-Specific and Stimulus-Nonspecific Firing Synchrony and Its Modulation by Sensory Adaptation in the Whisker-to-Barrel Pathway
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DOI：
10.1152/jn.91151.2008
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发表时间：
2009-05-01
影响因子：
2.5
通讯作者：
Simons, Daniel J.
中科院分区：
文献类型：
--
作者：
Khatri, Vivek;Bruno, Randy M.;Simons, Daniel J.
Khatri V, Bruno RM, Simons DJ。刺激特异性和刺激非特异性放电同步及其在须-管通路中的感觉适应调节。[J]中国生物医学工程学报，2009,31(2):559 - 559。2009年3月11日首次发表；doi: 10.1152 / jn.91151.2008。皮层神经元的刺激诱发反应既取决于传入信号的细节，也取决于它所处的更大网络的瞬时状态。因此，相同的感官刺激会引起高度不同的反应。通过同时记录大鼠须到桶通路中的丘脑桶状体和/或皮质桶状神经元，我们确定了在逐个试验的基础上成对细胞的反应协同变化的程度。在丘脑和皮层第四层，试验间可变性的一个重要组成部分独立于刺激的具体参数，这里用偏转角来探测。这些非特异性刺激效应导致同时记录的桶状神经元对在试验平均角度调谐上的相似性大于偶然。在同时记录的丘脑和皮质桶状神经元中没有观察到这种效应，这表明有很强的皮质内同步机制。由先前的晶须偏转产生的感觉适应降低了反应幅度，增强了同时记录的神经元的关节角调谐。适应也解除了刺激诱发反应的相关性，使神经元对的逐个反应变得不那么相似。适应诱导的去关联加上关节调谐的增强可以增强丘脑或皮层内细胞的显著性，这些细胞在与主动触觉相关的持续触觉刺激中继续同步放电。
Khatri V, Bruno RM, Simons DJ. Stimulus-specific and stimulus-nonspecific firing synchrony and its modulation by sensory adaptation in the whisker-to-barrel pathway. J Neurophysiol 101: 2328-2338, 2009. First published March 11, 2009; doi:10.1152/jn.91151.2008. The stimulus-evoked response of a cortical neuron depends on both details of the afferent signal and the momentary state of the larger network in which it is embedded. Consequently, identical sensory stimuli evoke highly variable responses. Using simultaneous recordings of thalamic barreloid and/or cortical barrel neurons in the rat whisker-to-barrel pathway, we determined the extent to which the responses of pairs of cells covary on a trial-by-trial basis. In the thalamus and cortical layer IV, a substantial component of trial-to-trial variability is independent of the specific parameters of the stimulus, probed here using deflection angle. These stimulus-nonspecific effects resulted in greater-than-chance similarities in trial-averaged angular tuning among simultaneously recorded pairs of barrel neurons. Such effects were not observed among simultaneously recorded thalamic and cortical barrel neurons, suggesting strong intracortical mechanisms of synchronization. Sensory adaptation produced by prior whisker deflections reduced response magnitudes and enhanced the joint angular tuning of simultaneously recorded neurons. Adaptation also decorrelated stimulus-evoked responses, rendering trial-by-trial responses of neuron pairs less similar to each other. Adaptation-induced decorrelation coupled with sharpened joint tuning could enhance the saliency of cells within thalamus or cortex that continue to fire synchronously during ongoing tactile stimulation associated with active touch.