A novel site of synaptic relay for climbing fibre pathways relaying signals from the motor cortex to the cerebellar cortical C1 zone
A novel site of synaptic relay for climbing fibre pathways relaying signals from the motor cortex to the cerebellar cortical C1 zone
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DOI：
10.1113/jphysiol.2006.114215
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发表时间：
2006-10-15
影响因子：
5.5
通讯作者：
Apps, Richard
中科院分区：
文献类型：
--
作者：
Ackerley, Rochelle;Pardoe, Joanne;Apps, Richard
采用生理学、解剖学和神经药理学相结合的方法，研究了大鼠小脑后叶运动皮质向小脑皮质C1区的攀爬纤维投射。电刺激同侧前额叶或后额叶或对侧运动皮质的躯体位置对应部分，在相同的小脑记录部位诱发攀爬纤维场电位。前肢相关的反应位于C1区的旁正中小叶或小叶单纯和后肢相关的反应位于C1区的连接。顺行轴突示踪剂（荧光红宝石或荧光祖母绿）的微注射到运动皮层的前肢或后肢部分，刺激引起最大的小脑反应。在7-10天的存活期后，检查轴突的顺行标记。没有终端标签被发现在下橄榄，但标记终端始终发现在一个很好的本地化网站在背内侧延髓，腹侧薄核，称为矩阵区域。药理学失活的基质区域（2毫米尾向obex）选择性地减少传输下行（脊髓-橄榄小脑），但不上升（脊髓-橄榄小脑）的路径，针对前肢或后肢接收部分的C1区。脊髓橄榄小脑路径的传输要么不受影响，或在某些情况下增加。识别一种新的前橄榄中继在前橄榄小脑路径起源于前肢和后肢运动皮层的影响，在自愿运动和运动学习过程中的攀登纤维通路的传输调节。
The climbing fibre projection from the motor cortex to the cerebellar cortical C1 zone in the posterior lobe of the rat cerebellum was investigated using a combination of physiological, anatomical and neuropharmacological techniques. Electrical stimulation of the ipsilateral fore- or hindimbs or somatotopically corresponding parts of the contralateral motor cortex evoked climbing fibre field potentials at the same cerebellar recording sites. Forelimb-related responses were located in the C1 zone in the paramedian lobule or lobulus simplex and hindlimb-related responses were located in the C1 zone in the copula pyramidis. Microinjections of anterograde axonal tracer (Fluoro-Ruby or Fluoro-Emerald) were made into the fore- or hindlimb parts of the motor cortex where stimulation evoked the largest cerebellar responses. After a survival period of 7-10 days, the neuraxis was examined for anterograde labelling. No terminal labelling was ever found in the inferior olive, but labelled terminals were consistently found in a well-localized site in the dorso-medial medulla, ventral to the gracile nucleus, termed the matrix region. Pharmacological inactivation of the matrix region (2 mm caudal to the obex) selectively reduced transmission in descending (cerebro-olivocerebellar) but not ascending (spino-olivocerebellar) paths targeting fore- or hindlimb-receiving parts of the C1 zone. Transmission in spino-olivocerebellar paths was either unaffected, or in some cases increased. The identification of a novel pre-olivary relay in cerebro-olivocerebellar paths originating from fore- and hindlimb motor cortex has implications for the regulation of transmission in climbing fibre pathways during voluntary movements and motor learning.