Discharge of primate magnocellular red nucleus neurons during reaching to grasp in different spatial locations.
Discharge of primate magnocellular red nucleus neurons during reaching to grasp in different spatial locations.
复制标题
灵长类大细胞红核神经元在到达不同空间位置时的放电。
DOI：
10.1007/s00221-001-0924-5
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
McCurdy,MarthaL
中科院分区：
文献类型：
--
作者：
vanKan,PeterLE;McCurdy,MarthaL
伸手抓握对灵长类动物的运动行为至关重要。红核脊髓束是控制这种行为的下行运动通路之一。红核脊髓束起源的一个重要来源是大细胞红核（RNm）。前肢RNm神经元在伸手抓握运动期间剧烈放电。RNm放电对于手部使用很重要，因为不使用手部的协调全肢运动与强放电无关。由于RNm在功能上与整个前肢的肌肉相连，因此RNm放电也可能有助于伴随手部使用的近端肢体的使用。如果RNm有助于近端肢体的使用，我们预测放电不同的达到不同的近端肢体参与，但需要相同的把握。我们通过测量单个RNm神经元的放电来测试这一预测，同时猴子在它们面前的四个空间位置抓住物体。动物从腰部到达“伸展”肢体肩部的左侧、右侧、上方和下方的位置。我们样本的RNm神经元在伸手抓握过程中被强烈激活，并且三分之一的测试神经元的放电取决于所抓握物体的空间位置。我们测试的许多远侧和近侧前肢肌肉的RNm神经元和EMG活动的放电对于在上部和/或右侧中达到抓握比下部和左侧目标位置更大。基于每个单独的神经元的放电模式的比较，在达到和不预塑形的手，我们得出结论，目标位置依赖性调制的放电率的大多数RNm神经元的放电不同，达到掌握在四个目标位置的贡献方面的手预塑形，与达到方向。
Reaching to grasp is of fundamental importance to primate motor behavior. One descending motor pathway that contributes to the control of this behavior is the rubrospinal tract. An important source of origin of the rubrospinal tract is the magnocellular red nucleus (RNm). Forelimb RNm neurons discharge vigorously during reach-to-grasp movements. RNm discharge is important for hand use, as coordinated whole-limb movements without hand use are not associated with strong discharge. Because RNm is functionally linked to muscles of the entire forelimb, RNm discharge may also contribute to use of the proximal limb that accompanies hand use. If RNm contributes to proximal limb use, we predict discharge to differ for reaches that differ in proximal limb involvement but require the same grasp. We tested this prediction by measuring discharge of individual RNm neurons while monkeys reached to grasp objects in four spatial locations in front of them. The animals reached from the waist to locations to the left, right, above, and below the shoulder of the "reaching" limb. RNm neurons of our sample were activated strongly during reach-to-grasp, and discharge of a third of the neurons tested depended on the spatial location of the object grasped. Discharge of RNm neurons and EMG activity of many of the distal and proximal forelimb muscles we tested were larger for reaching to grasp in the upper and/or right than lower and left target locations. Based on comparisons of each individual neuron's discharge patterns during reaches with and without preshaping the hand, we conclude that target location-dependent modulations in discharge rate of the majority of RNm neurons whose discharge differed for reaching to grasp in the four target locations contributed to aspects of hand preshaping that covaried with reach direction.