Sillito A M, Kemp J A, Berardi N
Brain Res. 1983 Dec 5;280(2):299-307. doi: 10.1016/0006-8993(83)90059-8.
The functional influence of the cholinergic input to cat dLGN has been examined by assessing the action of iontophoretically applied acetylcholine (ACh) on the visual responses of cells in layers A and A1. Iontophoretically applied pulses of ACh exerted a strong excitatory action on all 113 cells studied within these layers. In the presence of a sustained application of ACh, the excitatory responses to an optimal stimulus such as a spot of light located within the receptive field centre were greatly facilitated, but at the same time stimulus-specific inhibitory influences were also enhanced. The action of ACh on the stimulus-specific inhibitory influences had the consequence that the responses to non-optimal stimuli were not facilitated to the same extent as those to optimal stimuli and in some cases even diminished. The stimulus-specific inhibitory effects seen in the presence of ACh were very powerful and frequently resulted in complete suppression of the elevated background discharge. We suggest that the ACh directly excites both the relay cells and the Golgi type II inhibitory interneurones within the dLGN. The facilitation of the stimulus-specific inhibition may follow from a direct action on the presynaptic dendrites of the Golgi type II cells which arborize within the dendritic field of the relay cell. Supplementary observations on cells in the perigeniculate nucleus confirm previous findings showing that ACh has an inhibitory effect on these cells. We suggest a tripartite action for the cholinergic influence on the dLGN, involving direct facilitation of relay cells, enhancement of stimulus-specific inhibition via the Golgi type II cells, and disinhibition of the non-specific inhibitory influence form the perigeniculate nucleus.
通过评估离子电渗法施加的乙酰胆碱（ACh）对猫背外侧膝状体核（dLGN）A层和A1层细胞视觉反应的作用，研究了胆碱能输入对猫dLGN的功能影响。离子电渗法施加的ACh脉冲对这些层内研究的所有113个细胞都产生了强烈的兴奋作用。在持续施加ACh的情况下，对诸如位于感受野中心的光点等最佳刺激的兴奋反应得到极大促进，但同时刺激特异性抑制作用也增强。ACh对刺激特异性抑制作用的影响导致对非最佳刺激的反应不像对最佳刺激的反应那样得到同等程度的促进，在某些情况下甚至减弱。在ACh存在下观察到的刺激特异性抑制作用非常强大，经常导致完全抑制升高的背景放电。我们认为，ACh直接兴奋dLGN内的中继细胞和高尔基II型抑制性中间神经元。刺激特异性抑制作用的促进可能源于对高尔基II型细胞突触前树突的直接作用，这些树突在中继细胞的树突场内分支。对膝状周核细胞的补充观察证实了先前的发现，即ACh对这些细胞有抑制作用。我们提出胆碱能对dLGN的影响具有三方作用，包括直接促进中继细胞、通过高尔基II型细胞增强刺激特异性抑制以及解除来自膝状周核的非特异性抑制作用。
