Activation of cat SII cortex by flutter stimulation of contralateral vs. ipsilateral forepaws.
Activation of cat SII cortex by flutter stimulation of contralateral vs. ipsilateral forepaws.
复制标题
通过对侧与同侧前爪的扑动刺激来激活猫 SII 皮质。
DOI：
10.1016/j.brainres.2005.11.073
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Tommerdahl,Mark
中科院分区：
文献类型：
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作者：
Favorov,OlegV;Whitsel,BarryL;Chiu,JoannellynS;Tommerdahl,Mark
SII皮质的一个显著特征是它从位于身体两侧的皮肤机械感受器接收大量输入。它仍然是不确定的，但是，如果集成的双边输入主要发生在这些地区的SII代表近中线的身体区域或也发生在一个显着的程度上在这些地区的SII代表远端四肢。这个问题得到解决，使用细胞外微电极记录在猫SII结合光学固有信号（OIS）成像的方法。用25-Hz正弦垂直皮肤位移（“皮肤颤动”）刺激对侧或同侧前爪的中央垫，在SII的广泛前后部分诱发突出的OIS反应（“激活”）。在前部位于SII区域，产生最大的OIS反应刺激对侧中央垫，神经元始终拥有接受领域，包括刺激的皮肤部位。该“前爪”SII区域也表现出显著的，尽管响应于同侧中央垫的刺激弱75%的OIS激活。刺激对侧或同侧前爪的中央垫也诱发了OIS激活位于后方的“后肢”区域的SII-定义为SII区域的神经元与对侧后肢的感受野组成。同侧中央垫刺激的OIS反应是最强的后SII区，边界的上裂边缘，在该地区的神经元有非常大的，经常双边，皮肤感受野。结果表明，猫SII内的广泛区域接收皮肤输入从同侧远侧前肢。这表明，这些同侧输入的功能作用可能是不同的，在不同的SII区。
A distinguishing feature of SII cortex is that it receives substantial input from skin mechanoreceptors located on both sides of the body. It remains uncertain, however, if integration of bilateral inputs occurs mainly in those regions of SII that represent near-midline body regions or also occurs to a significant extent in those regions of SII that represent the distal extremities. This issue was addressed using extracellular microelectrode recordings in cat SII in combination with the method of optical intrinsic signal (OIS) imaging. Stimulation of the central pad of either the contra- or ipsilateral forepaw with a 25-Hz sinusoidal vertical skin displacement (“skin flutter”) stimulus evoked a prominent OIS response (“activation”) in an extensive anteroposterior sector of SII. In the anteriorly located SII region that yielded the maximal OIS response to stimulation of the contralateral central pad, neurons consistently possessed receptive fields that included the stimulated skin site. This “forepaw” SII region also exhibited significant although 75% weaker OIS activation in response to stimulation of the ipsilateral central pad. Stimulation of the central pads of either contra- or ipsilateral forepaws also evoked OIS activation in the posteriorly located ‘hindlimb’ region of SII—defined as the SII region comprised of neurons with receptive fields on the contralateral hindlimb. The OIS response to ipsilateral central pad stimulation was strongest in the posterior SII region that borders the suprasylvian fringe—a region in which neurons have very large, and frequently bilateral, cutaneous receptive fields. The results indicate that widespread regions within cat SII receive cutaneous inputs from the ipsilateral distal forelimb. It is suggested that the functional role of these ipsilateral inputs may be different in different SII regions.