Objective To determine whether the convergences of tactile information also occur at thalamic ventroposterolateral nucleus in rats, we investigated the properties of tactile responses of the thalamic ventroposterolateral nucleus in rats. Methods Unit responses were recorded extracellularly from thalamic ventroposterolateral nucleus in anesthetized rats. Results Among 156 neurons examined, 140 neurons （89.7%） had the single, continual and small receptive fields, and 16 neurons （10.3%） had two discrete receptive fields. Some neurons exhibited different responses to the same intensity stimulation which delivered to different points in their receptive fields. In addition, 4.5% neurons （n -- 7） responded only to locomotive stimulation but not to a punctiform tactile stimulation. Conclusion The majority of neurons in ventroposterolateral nucleus of rats have the spatial, temporal and submodal characteristics of cutaneous receptors, while the minority of neurons exhibit the responses of interaction of different peripheral receptors. Therefore, it is con- cluded that there are convergences of tactile information at the ventroposterolateral nucleus of rats.
目的:探讨触觉刺激对触觉注意的影响,以揭示选择性注意的机制。方法:利用在体电生理记录技术,记录了288个丘脑腹侧基底核(ventrobasal nuleus of thalamus,VB)神经元放电活动,并着重考察了不同强度触觉刺激对丘脑神经元细胞自发放电活动的影响。结果发现:触觉刺激对大部分的触觉神经元的自发放电活动均有抑制性影响。提示触觉刺激降低背景噪声可能是触发选择性触觉注意的神经机制。
