Cooke Dylan F, Graziano Michael S A
Department of Psychology, Princeton University, Princeton, New Jersey 08544, USA.
Neuron. 2004 Aug 19;43(4):585-93. doi: 10.1016/j.neuron.2004.07.029.
In a restricted zone of the monkey motor cortex, neurons respond to objects near, approaching, or touching the body. This polysensory zone was hypothesized to play a role in monitoring nearby stimuli for the guidance of defensive movements. To test this hypothesis, we chemically manipulated sites within that zone by injecting bicuculline (increasing neuronal activity) or muscimol (decreasing neuronal activity). Bicuculline caused the monkey to react in an exaggerated fashion to an air puff on the face and to objects approaching the face, whereas muscimol caused the monkey to react in a reduced fashion. The effects were expressed partly as a motor abnormality (affecting movement of the musculature contralateral to the injection site) but also partly as a sensory enhancement or sensory neglect (affecting responses to stimuli contralateral to the injection site). These findings suggest that the polysensory zone contributes to the ethologically important function of defense of the body.
在猴子运动皮层的一个受限区域内，神经元会对靠近、接近或触碰身体的物体产生反应。这个多感觉区域被推测在监测附近刺激以指导防御动作方面发挥作用。为了验证这一假设，我们通过注射荷包牡丹碱（增加神经元活动）或蝇蕈醇（降低神经元活动）对该区域内的位点进行化学操纵。荷包牡丹碱使猴子对面部吹气和靠近面部的物体产生过度夸张的反应，而蝇蕈醇则使猴子的反应减弱。这些影响部分表现为运动异常（影响注射部位对侧的肌肉组织运动），但也部分表现为感觉增强或感觉忽视（影响对注射部位对侧刺激的反应）。这些发现表明，多感觉区域有助于身体防御这一具有行为学重要性的功能。
