Martin J H, Spencer W A
Brain Res. 1985 Feb 18;327(1-2):279-88. doi: 10.1016/0006-8993(85)91521-5.
This study examined whether afferent inhibition generated by activation of one mechanoreceptive submodality influences the response of neurons of the other submodality tested. Response properties of quickly adapting hair and Pacinian neurons in primary somatosensory cortex of the cat were evaluated to assess afferent inhibition generated by single-cycle sinusoidal mechanical stimuli. Animals were lightly anesthetized with sodium thiopental. Stimulation at 20 Hz (low-velocity stimulus) was used to activate hair cells, the receptive fields of which were located in the skin; stimulation at 200 Hz (high-velocity stimulus) was used to activate Pacinian cells, the receptive fields of which were located in the deeper tissues. The skin was partially dissected from the deeper tissue in order to uncouple mechanically the effective receptive surfaces and to achieve greater selectivity. Hair and Pacinian cell test responses were paired with single-cycle 20 and 200 Hz conditioning stimuli. A 20 Hz stimulus, more effective in activating hair cells than Pacinian cells, strongly inhibited the test response of hair cells only and a 200 Hz stimulus, which is more effective in activating Pacinian cells than hair cells, markedly inhibited the test response of Pacinian cells only. Our data indicate that afferent inhibition generated by activation of one submodality channel is largely confined to that submodality channel and is not distributed to the other.
本研究检测了由一种机械感受亚模态的激活所产生的传入抑制是否会影响所测试的另一种亚模态神经元的反应。对猫的初级体感皮层中快速适应的毛细胞和环层小体神经元的反应特性进行评估，以评定由单周期正弦机械刺激产生的传入抑制。动物用硫喷妥钠轻度麻醉。以20赫兹的刺激（低速刺激）来激活毛细胞，其感受野位于皮肤；以200赫兹的刺激（高速刺激）来激活环层小体细胞，其感受野位于更深层组织。为了在机械上分离有效的感受表面并实现更高的选择性，将皮肤与深层组织部分剥离。毛细胞和环层小体细胞的测试反应与单周期20赫兹和200赫兹的条件刺激配对。20赫兹的刺激在激活毛细胞方面比激活环层小体细胞更有效，仅强烈抑制毛细胞的测试反应；而200赫兹的刺激在激活环层小体细胞方面比激活毛细胞更有效，仅显著抑制环层小体细胞的测试反应。我们的数据表明，由一种亚模态通道的激活所产生的传入抑制在很大程度上局限于该亚模态通道，而不会分布到另一个通道。
