Responses of Areas 3b and 1 in Anesthetized Squirrel Monkeys to Single- and Dual-Site Stimulation of the Digits
Responses of Areas 3b and 1 in Anesthetized Squirrel Monkeys to Single- and Dual-Site Stimulation of the Digits
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DOI：
10.1152/jn.90278.2008
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发表时间：
2008-12-01
影响因子：
2.5
通讯作者：
Roe, Anna W.
中科院分区：
文献类型：
--
作者：
Friedman, Robert M.;Chen, Li Min;Roe, Anna W.
刺激皮肤会引起躯体感觉皮层的局部组织激活。然而，这种表示是依赖于上下文的，因为当用引起冯·贝克斯功能错觉的复杂触觉刺激刺激时，在3b区观察到不同的皮层地形。在这里，我们报告的人口反应，观察与内在光学成像，在麻醉的松鼠猴1区和3b区的压力压痕远端指垫。单个指垫刺激显示，区域1表现出比3b更小的放大因子，这可以通过远端指垫刺激引起的更小的激活区域来证明。配对指垫刺激的效果在区域1和区域3b中产生大致相似的效果。成对的指垫刺激产生的数字激活区1的面积减少，表明存在侧抑制和functioning的信息在1区。在相邻的配对刺激比在非相邻网站的抑制作用更强。单单位记录显示的混合物的总和或抑制的反应，成对的手指刺激，与单一的手指垫刺激的主要数字。然而，平均群体反应表明，配对指垫刺激导致反应抑制。基于这项研究和以前的研究，我们建议存在至少三个不同的范围内的侧抑制在3b区和1。
Stimulation of the skin evokes topographically organized activation in somatosensory cortex. This representation is context dependent, however, since a different cortical topography is observed in area 3b when stimulated with complex tactile stimuli that evoke the von Bekesy funneling illusion. Here we report on the population responses, as observed with intrinsic optical imaging, of area 1 and area 3b in the anesthetized squirrel monkey to pressure indentation of distal finger pads. Individual finger pad stimulation revealed that area 1 exhibited a smaller magnification factor than 3b, as evidenced by a smaller area of activation elicited by distal finger pad stimulation. Effects of paired finger pad stimulation produced largely similar effects in area 1 and area 3b. Paired finger pad stimulation produced reductions in the area of digit activation in area 1, suggesting the presence of lateral inhibition and funneling of information in area 1. Suppressive effects were stronger for paired stimulations at adjacent than at nonadjacent sites. Single-unit recordings revealed a mixture of either a summation or a suppression of the response to paired finger stimulation, compared with single finger pad stimulation of the primary digit. However, the average population response showed that paired finger pad stimulation resulted in response suppression. Based on this study and previous studies, we suggest the presence of at least three distinct ranges of lateral inhibition in areas 3b and 1.