Dissociation of sensorimotor deficits after rostral versus caudal lesions in the primary motor cortex hand representation
Dissociation of sensorimotor deficits after rostral versus caudal lesions in the primary motor cortex hand representation
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DOI：
10.1152/jn.01251.2004
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发表时间：
2005-08-01
影响因子：
2.5
通讯作者：
Nudo, RJ
中科院分区：
文献类型：
--
作者：
Friel, KM;Barbay, S;Nudo, RJ
初级运动皮质(M1)传统上被认为是一种运动结构。虽然神经生理学研究表明M1也受到躯体感觉输入(皮肤和本体感觉)的影响，但这些输入在灵长类动物中的行为意义尚未完全确定。本研究描述了在非人类灵长类动物的M1手部区域的吻侧或尾侧区域的小的缺血性损害后的不同的感觉相关缺陷。松鼠猴子从钻入有机玻璃板上的不同大小的井中取出食物颗粒。在损伤之前，猴子通过将手指向井中，将手指直接插入井中，并提取颗粒来取回颗粒。在M1的吻部受损后，猴子经常无法准确地将手指向井。取而代之的是，在进入井之前，手指接触了井外的板面。这些瞄准误差与近端运动输出的大量和吻端M1的主要本体感觉输入是一致的。总体而言，这些瞄准错误暗示了本体感觉信息处理的功能障碍，或者本体感觉信息与运动指令的整合失败。相比之下，在M1的尾部受损后，猴子在尝试取回后，经常用视觉检查他们的手掌是否存在小球。这些误差与远端运动输出的大量和尾侧M1的主要皮肤输入是一致的。因此，这些错误暗示了皮肤信息处理的缺陷或未能将皮肤信息与运动指令相结合。吻侧和尾侧M1损伤导致感觉依赖性运动控制的不同缺陷，这似乎与运动输出和先前描述的M1感觉输入的广泛分离有关。
Primary motor cortex (M1) has traditionally been considered a motor structure. Although neurophysiologic studies have demonstrated that M1 is also influenced by somatosensory inputs ( cutaneous and proprioceptive), the behavioral significance of these inputs has yet to be fully defined in primates. The present study describes differential sensory-related deficits after small ischemic lesions in either the rostral or caudal subregion of the M1 hand area in a nonhuman primate. Squirrel monkeys retrieved food pellets out of different sized wells drilled into a Plexiglas board. Before the lesion, monkeys retrieved pellets by directing the hand to the well, inserting fingers directly into it, and extracting the pellet. After a lesion to the rostral portion of M1, monkeys frequently failed to direct the hand accurately to the well. Instead, fingers contacted the surface of the board outside the well before entering the well. These aiming errors are consistent with both the large amount of proximal motor outputs and the predominant proprioceptive inputs of rostral M1. Overall, these aiming errors are suggestive of dysfunctional processing of proprioceptive information or the failure to integrate proprioceptive information with motor commands. In contrast, after a lesion to the caudal portion of M1, monkeys frequently examined their palm visually for the presence of the pellet after an attempted retrieval. These errors are consistent with both the large amount of distal motor outputs and the predominant cutaneous inputs of caudal M1. Thus these errors are suggestive of a deficit in processing of cutaneous information or the failure to integrate cutaneous information with motor commands. Rostral and caudal M1 lesions result in different deficits in sensory-dependent motor control that appear to correlate with broad segregation of motor outputs and previously described sensory inputs of M1.