THE PRIMATE SUBTHALAMIC NUCLEUS .1. FUNCTIONAL-PROPERTIES IN INTACT ANIMALS
THE PRIMATE SUBTHALAMIC NUCLEUS .1. FUNCTIONAL-PROPERTIES IN INTACT ANIMALS
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DOI：
10.1152/jn.1994.72.2.494
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发表时间：
1994-08-01
影响因子：
2.5
通讯作者：
DELONG, MR
中科院分区：
文献类型：
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作者：
WICHMANN, T;BERGMAN, H;DELONG, MR
1.本研究测试了基底神经节的内在电路的电流模型的几个关键方面，特别是在何种程度上，基底神经节丘脑皮质电路功能隔离在丘脑底核的水平（ESTA）。为此，在三只非洲绿色猴的STNs中研究了体感检查（n = 301个细胞）的感觉神经元反应、被动和主动运动（n = 223个细胞）的神经元反应的极性和潜伏期、微刺激（n = 1589个位点）的反应以及相邻神经元对（n = 72对）的交叉相关函数.活动的55%的细胞检查，在快速调制响应个别对侧身体部位的被动运动。其中，86%对肌肉触诊的被动关节旋转有反应，但在某些情况下（25%的反应细胞）也会通过轻触引起反应。在91%的反应细胞中，仅通过单个关节周围的操作引起反应。尾腹侧区在很大程度上缺乏对体感刺激有反应的细胞。在rostrodoral区的外侧区域含有神经元，响应手臂的运动和一个更内侧的区域与神经元响应腿的运动被发现。对肢体主动和被动运动具有相似反应的神经元倾向于聚集在“臂"和”腿“区域内。在已识别的手臂细胞中，36%的手臂细胞对手肘的扭矩脉冲有反应（共43次反应）。这些细胞中有48%对伸展和屈曲扭矩都有反应。93%的反应是放电的初始增加，其特征是比初始减少更早发生且更短。53%的反应是双相或多相的。在积极的步骤跟踪运动40%的前臂细胞（n = 53细胞）的反应与活动的显着变化。这些细胞中有36%表现出伸展和屈曲运动的反应。90%的反应是放电增加。只有14%的反应是双相或多相的。反应往往发生在运动开始的时间（运动开始后的平均潜伏期为2 ms）。微刺激（双极脉冲，40 μ A，200-500毫秒的列车持续时间，400赫兹）的核心，脊髓本身没有出现产生运动。然而，在外侧边界的刺激，以及相邻的白色物质往往导致肢体或眼睛的运动。同时记录的神经元对的交叉相关分析显示，只有11%的神经元对具有显著的同步活动。神经元反应的躯体位置排列和相邻细胞同步放电的缺乏强烈支持基底节-丘脑皮质通路功能分离的概念。运动时脑内放电的快速增加的优势很可能是皮质下丘脑激活的结果。目前的基底神经节解剖模型预测，这将导致运动抑制。电刺激神经核不能诱导运动，这进一步支持了多巴胺在运动控制中的抑制作用。在步跟踪任务中，海马神经元的反应出现较晚，这表明海马神经元和“间接"通路不参与运动的选择或启动，但可能在控制正在进行的运动中发挥作用。
1. The present study tests several key aspects of the current model of the intrinsic circuitry of the basal ganglia, in particular the degree to which basal ganglia-thalamocortical circuits are functionally segregated at the level of the subthalamic nucleus (STN). To this end the responses of STN cells to somatosensory examination (n = 301 cells), the polarity and latencies of neuronal responses to passive and active movements (n = 223 cells), responses to microstimulation(n = 1589 sites), and cross-correlation functions of pairs of neighboring neurons ( n = 72 pairs) were studied in STNs of three African green monkeys.2. The activity of 55% of cells examined in STN was briskly modulated in response to passive movements of individual contralateral body parts. Of these, 86% responded to passive joint rotation of muscle palpation, but in some cases (25% of responding cells) responses were also elicited by light touch. In 91% of the responding cells responses were elicited by manipulations around a single joint only.3. The caudoventral sector in STN was largely devoid of cells with responses to somatosensory stimulation. Within the rostrodorsal zone a lateral region containing neurons that responded to arm movements and a more medial region with neurons responding to leg movement were found. Cells responding to orofacial movements were located more dorsally and rostrally. Neurons with similar responses to active and passive movements of the limbs tended to be clustered within ''arm'' and ''leg'' zones.4. Of identified arm cells in STN (n = 80), 36% responded to the application of torque pulses to the elbow (43 responses overall). Forty-eight percent of these cells responded to both extension and flexion torques. Ninety-three percent of the responses were initial increases in discharge, which characteristically occurred earlier and were shorter than initial decreases. Fifty-three percent of the responses were biphasic or multiphasic.5. During active step tracking movements 40% of STN arm cells (n = 53 cells) responded with significant changes in activity. Thirty-six percent of these cells showed responses with both extension and flexion movements. Of the responses, 90% were increases in discharge. Only 14% of all responses were biphasic or multiphasic. Responses tended to occur around the time of movement onset (average latency 2 ms after movement onset).6. Microstimulation (bipolar pulses, 40 mu A, 200-500 ms train duration, 400 Hz) of the core of STN itself did not appear to produce movement. However, stimulation at the lateral borders of STN and of the adjacent white matter often led to limb or eye movement.7. Cross-correlation analysis of simultaneously recorded pairs of neurons revealed significant synchronized activity in only 11% of pairs.8. The somatotopic arrangement of neuronal responses and the paucity of neighboring cells discharging in synchrony strongly support the concept of functional segregation in the basal ganglia-thalamocortical pathways. The predominance of brisk increases in discharge in STN in response to movements most likely results from corticosubthalamic activation. The current model of basal ganglia anatomy predicts that this will lead to inhibition of movements. The inhibitory role of STN in motor control is further supported by the failure of electrical stimulation of the nucleus to induce movements. The late onset of responses of STN neurons in the step tracking task suggests that STN and the ''indirect'' pathway are not involved in the selection or initiation of movements, but may rather have a role in the control of ongoing movements.