Convergence of Submodality-Specific Input Onto Neurons in Primary Somatosensory Cortex
Convergence of Submodality-Specific Input Onto Neurons in Primary Somatosensory Cortex
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DOI：
10.1152/jn.00235.2009
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发表时间：
2009-09-01
影响因子：
2.5
通讯作者：
Bensmaia, Sliman J.
中科院分区：
文献类型：
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作者：
Pei, Yu-Cheng;Denchev, Peter V.;Bensmaia, Sliman J.
裴永成，Denchev PV, Hsiao SS, Craig JC, Bensmaia SJ。初级体感觉皮层亚模态特异性输入向神经元的收敛。中国生物医学工程学报（英文版）32(2):444 - 444。首次发表于2009年6月17日；doi: 10.1152 / jn.00235.2009。在体感觉外周，慢适应型1 （SA1）和快速适应型（RA）传入事件对阶跃凹痕的反应非常不同：SA1传入事件在整个刺激间隔中都有反应（持续反应），而RA传入事件仅在刺激开始（ON反应）和抵消（OFF反应）时有反应。我们记录了皮层神经元对台阶凹陷的反应，发现3b和1区的许多神经元表现出介于这两个极端之间的特性：这些神经元在刺激的持续部分和刺激的抵消部分都有反应。几条线索的证据表明，这些神经元，即使在体感觉皮层处理的早期阶段也大量存在，从两个传入事件群接收输入。首先，我们发现许多皮质神经元同时具有显著的持续反应和显著的OFF反应。其次，OFF反应的强度与持续反应的强度不相关，如果持续和OFF反应来自不同的传入纤维群，这是可以预料的。第三，皮层对台阶压痕反应的大部分差异可以用SA1和RA反应的线性组合来解释。最后，我们发现皮质神经元的OFF反应并不反映抑制后的反弹。我们得出的结论是，在初级体感觉皮层中，特定模态输入向单个神经元的收敛是常见的，并讨论了这一结论如何与先前的发现相一致。
Pei Y-C, Denchev PV, Hsiao SS, Craig JC, Bensmaia SJ. Convergence of submodality specific input onto neurons in primary somatosensory cortex. J Neurophysiol 102: 1843-1853, 2009. First published June 17, 2009; doi:10.1152/jn.00235.2009. At the somatosensory periphery, slowly adapting type 1 (SA1) and rapidly adapting (RA) afferents respond very differently to step indentations: SA1 afferents respond throughout the entire stimulus interval (SUSTAINED response), whereas RA afferents respond only at stimulus onset (ON response) and offset (OFF response). We recorded the responses of cortical neurons to step indentations and found many neurons in areas 3b and 1 to exhibit properties that are intermediate between these two extremes: These neurons responded during the sustained portion of the stimulus and also at the offset of the stimulus. Several lines of evidence indicate that these neurons, which exist in large proportions even at these early stages of somatosensory cortical processing, receive input from both populations of afferents. First, we show that many cortical neurons have both a significant SUSTAINED response and a significant OFF response. Second, the strength of the OFF response is uncorrelated with that of the SUSTAINED response, which is to be expected if SUSTAINED and OFF responses stem from different populations of afferent fibers. Third, the bulk of the variance in cortical responses to step indentations can be accounted for using a linear combination of both SA1 and RA responses. Finally, we show that the OFF response in cortical neurons does not reflect rebound from inhibition. We conclude that the convergence of modality specific input onto individual neurons is common in primary somatosensory cortex and discuss how this conclusion might be reconciled with previous findings.