Effect of exercise on visual cognitive function and its brain mechanism

据报道，体育锻炼可以改善人类和啮齿动物的几种认知功能，但其潜在的神经机制尚不清楚。由于运动过程中皮层神经调节剂的水平增加，运动对认知功能的影响可能是通过神经调节剂介导的。为了验证这种可能性，我测试了乙酰胆碱（ACh）对猴子和大鼠早期视觉皮层（V1）神经元视觉反应的影响。目前的研究结果总结如下：1)在猴V1中，乙酰胆碱对视觉反应的促进和抑制作用占主导地位；2)在大鼠V1中，乙酰胆碱对视觉反应的促进和抑制作用的频率大致相同；3)乙酰胆碱对视觉反应增益的控制作用，通过这种控制作用改变对比反应函数的振幅，但不改变其形状；4)乙酰胆碱受体对乙酰胆碱的作用负责；分别投射到高阶视觉区和皮层下区域。目前的研究表明乙酰胆碱比以前认为的更清晰、更精细地控制视觉信息处理。

Physical exercise has been reported to improve several kinds of cognitive function in human and rodents, but the underlying neuronal mechanisms remain unknown. Since the levels of cortical neuromodulators are increased during exercise, it is possible that the effect of exercise on cognitive function is mediated via the neuromodulators. To examine the possibility, I tested the effect of acetylcholine (ACh) on the visual response of neurons in the early visual cortex (V1) of monkey and rat. The present results are summarized as follows:1) in monkey V1, ACh dominantly facilitated the visual responses2) in rat V1, ACh caused response facilitation and suppression with approximately the same frequency3) ACh caused a response gain control, by which the amplitude of contrast-response function but not the shape was changed4) muscarinic ACh receptors were responsible for the ACh’s effect5) ACh predominantly suppressed layers 2/3 neurons but facilitated layer 5 neurons, which projects to the higher order visual area and to subcortical areas, respectively.The present study suggests that ACh more distinctly and finely controls visual information processing than previously thought.