Duration-dependent response of SI to vibrotactile stimulation in squirrel monkey.
Duration-dependent response of SI to vibrotactile stimulation in squirrel monkey.
复制标题
DOI：
10.1152/jn.00513.2006
复制
发表时间：
2007-03
影响因子：
2.5
通讯作者：
Stephen B. Simons;Joannellyn S. Chiu;O. Favorov;B. Whitsel;M. Tommerdahl
中科院分区：
文献类型：
--
作者：
Stephen B. Simons;Joannellyn S. Chiu;O. Favorov;B. Whitsel;M. Tommerdahl
在以前的研究中，我们表明，空间和密集方面的SI反应，皮肤扑动刺激修改系统的刺激幅度增加。在这项研究中，我们研究了皮肤扑动刺激的持续时间对SI皮层反应的时空特征的影响。应用光学固有信号（OIS）成像技术研究了25Hz正弦垂直皮肤位移刺激对麻醉松鼠猴SI的诱发反应。四个刺激持续时间进行了测试（0.5，1.0，2.0，和5.0秒），所有的刺激被传递到对侧前肢的无毛皮肤上的离散站点。皮肤刺激诱发了一个显着增加对侧半球的SI前肢区域内的吸光度。简短的（0.5秒）刺激的反应较弱，空间上更广泛的比反应更长的持续时间的刺激（1.0，2.0和5.0秒）。持续时间>或=1 s的刺激抑制了围绕最大激活区域的区域中低于背景水平的反应（吸光度降低）。在周围区域的抑制的幅度是不均匀的，通常是最强的内侧和后方的最大激活区。结果表明，持续（>或=1.0 s）的刺激减少了响应SI皮层群体的空间范围。注册的光学响应与先前记录的SI拓扑结构强烈表明，皮质区域，经历最强的抑制表示皮肤部位，通常是共同刺激触觉探索。
In previous studies, we showed that the spatial and intensive aspects of the SI response to skin flutter stimulation are modified systematically as stimulus amplitude is increased. In this study, we examined the effects of duration of skin flutter stimulation on the spatiotemporal characteristics of the response of SI cortex. Optical intrinsic signal (OIS) imaging was used to study the evoked response in SI of anesthetized squirrel monkeys to 25-Hz sinusoidal vertical skin displacement stimulation. Four stimulus durations were tested (0.5, 1.0, 2.0, and 5.0 s); all stimuli were delivered to a discrete site on the glabrous skin of the contralateral forelimb. Skin stimulation evoked a prominent increase in absorbance within the forelimb regions in SI of the contralateral hemisphere. Responses to brief (0.5 s) stimuli were weaker and spatially more extensive than responses to longer duration stimuli (1.0, 2.0, and 5.0 s). Stimuli >or=1 s in duration suppressed responses to below background levels (decreased absorbance) in regions that surrounded the maximally activated region. The magnitude of the suppression in the surrounding regions was nonuniform and usually was strongest medial and posterior to the maximally activated region. The results show that sustained (>or=1.0 s) stimulation decreases the spatial extent of the responding SI cortical population. Registration of the optical responses with the previously documented SI topographical organization strongly suggests that the cortical regions that undergo the strongest suppression represent skin sites that are normally co-stimulated during tactile exploration.