Cholinergic modulation of response gain in the primary visual cortex of the macaque
Cholinergic modulation of response gain in the primary visual cortex of the macaque
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猕猴初级视觉皮层反应增益的胆碱能调节
DOI：
10.1152/jn.00330.2011
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
H
中科院分区：
文献类型：
--
作者：
Soma;S.;Shimegi;S.;Osaki;H. and Sato;H
ACh调节整个大脑皮层的神经元活动，包括初级视觉皮层（V1）。然而，关于这种调节的一些问题仍然未知，例如作用及其功能和所涉及的受体亚型。为了解决这些问题，我们结合细胞外单单位记录和微离子电渗给药乙酰胆碱和测量V1神经元的反应漂移正弦光栅刺激麻醉猕猴。乙酰胆碱被发现主要有促进作用的视觉反应，虽然也看到了一些情况下的抑制作用。为了评估ACh的功能作用，我们进一步研究了ACh如何调节刺激对比反应功能，发现反应增益随着易化效应而增加。阿托品（At），毒蕈碱乙酰胆碱受体（mAChR）拮抗剂，在几乎所有的神经元（96%的细胞）的反应促进完全或强烈阻断，而任何残留的影响后，在管理完全删除的美加明，烟碱乙酰胆碱受体（nAChR）拮抗剂，这表明在这一机制中的主要作用mAChRs。此外，我们没有发现层状分布偏误的易化调制，虽然相对贡献较小的mAChRs在4C层比在其他层。这种压制效果，被At给完全屏蔽了。这些结果表明，ACh起着重要的作用，在视觉信息处理V1通过控制响应增益通过mAChRs在所有皮层层和通过nAChRs，主要是inlayer 4C。
ACh modulates neuronal activity throughout the cerebral cortex, including the primary visual cortex (V1). However, a number of issues regarding this modulation remain unknown, such as the effect and its function and the receptor subtypes involved. To address these issues, we combined extracellular single-unit recordings and microiontophoretic administration of ACh and measured V1 neuronal responses to drifting sinusoidal grating stimuli in anesthetized macaque monkeys. ACh was found to have mostly facilitatory effects on the visual responses, although some cases of suppressive effects were also seen. To assess the functional role of ACh, we further examined how ACh modulates the stimulus contrast-response function, finding that the response gain increased with the facilitatory effect. The response facilitation was completely or strongly blocked by atropine (At), a muscarinic ACh receptor (mAChR) antagonist, in almost all neurons (96% of cells), whereas any residual effect after At administration was fully removed by mecamylamine, a nicotinic AChR (nAChR) antagonist, suggesting a predominant role for mAChRs in this mechanism. Furthermore, we found no laminar distribution bias for the facilitatory modulation, although the relative contribution of mAChRs was smaller inlayer 4Cthan in other layers. The suppressive effect was blocked completely by At. These results demonstrate that ACh plays an important role in visual information processing in V1 by controlling the response gain via mAChRs across all cortical layers and via nAChRs, mainly inlayer 4C.