Receptive field properties of the macaque second somatosensory cortex: Representation of orientation on different finger pads
Receptive field properties of the macaque second somatosensory cortex: Representation of orientation on different finger pads
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DOI：
10.1523/jneurosci.5057-05.2006
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发表时间：
2006-06-14
影响因子：
5.3
通讯作者：
Hsiao, Steven S.
中科院分区：
文献类型：
--
作者：
Fitzgerald, Paul J.;Lane, John W.;Hsiao, Steven S.
方向调节在视觉系统中已经得到了广泛的研究，但在体感系统中却知之甚少。在这里，我们调查调谐在第二体感（SII）区域使用电动刺激器，提出了一个小的定向酒吧的12个手指垫的数字2-5（D2-D5）的猕猴。一个子集（23%; n = 218）的928个SII区神经元[与Fitzgerald等人（2004，2006）研究的928个神经元相同]表现出调谐，并且这些神经元中的大多数在一个或两个指垫上调谐。所有八个22.5度分离的方向被表示为多个神经元的优选方向，尽管不一定数量相等。带宽的测量表明，在SII区域的调谐是尖锐的，是类似于在视觉皮层区观察到的调谐。此外，拟合调谐曲线的二维高斯曲线具有非常高的r（2）值，这表明大多数调谐曲线都是单峰的，并且相对于其首选方向对称。大多数调谐神经元有额外的非调谐垫，虽然这些垫的反应往往是低于调谐垫的反应。具有多个调谐垫的神经元倾向于在其调谐垫上具有相似的偏好取向，这可以被解释为跨手指的信息整合的证据或作为位置不变性的一种形式。最后，调谐性能的比较表明，有小的，但显着的差异之间的后，中央和前领域的SII区域。
Orientation tuning has been studied extensively in the visual system, but little is known about it in the somatosensory system. Here we investigate tuning in the second somatosensory (SII) region using a motorized stimulator that presented a small oriented bar to the 12 finger pads of digits 2-5 (D2-D5) of the macaque monkey. A subset (23%; n = 218) of the 928 SII region neurons [the same 928 neurons studied by Fitzgerald et al. (2004, 2006)] exhibited tuning, and most of these were tuned on one or two finger pads. All eight 22.5 degrees separated orientations were represented as the preferred orientation of multiple neurons, although not necessarily in equal numbers. A measure of bandwidth indicated that tuning in the SII region is sharp and is similar to the tuning observed in visual cortical areas. In addition, two-dimensional Gaussians that were fit to the tuning curves had very high r(2) values, indicating that most tuning curves are both unimodal and symmetrical with respect to their preferred orientation. Most tuned neurons had additional untuned pads, although the responsiveness of these pads tended to be less than the responsiveness of tuned pads. Neurons with multiple tuned pads tended to have similar preferred orientations on their tuned pads, which can be interpreted as evidence for integration of information across fingers or as a form of positional invariance. Finally, comparison of the tuning properties showed that there are small but significant differences between the posterior, central, and anterior fields of the SII region.