Dexterous finger movements in primate without monosynaptic corticomotoneuronal excitation
Dexterous finger movements in primate without monosynaptic corticomotoneuronal excitation
复制标题
DOI：
10.1152/jn.00342.2004
复制
发表时间：
2004-11-01
影响因子：
2.5
通讯作者：
Ohki, Y
中科院分区：
文献类型：
--
作者：
Sasaki, S;Isa, T;Ohki, Y
人们普遍认为，猴和人的精确握力和独立手指运动(IFMS)是由直接(单突触)皮质突触(CM)通路控制的。这一观点是基于先前的观察，即锥体切开术导致IFMS近乎永久性的缺陷。然而，除了直接的CM通路外，锥体切开术还中断了几个到脑干和上颈段的皮质分离连接。间接(寡突触)CM通路在系统发育上更古老，一直被认为在抓握中几乎或根本不重要。在3只成年猕猴上，在前肢节段(C-6-Th-1)吻侧的C-4/C-5建立了CM直接通路的完整横断区。电生理记录显示缺乏直接外侧皮质脊髓束(LCST)抽射、运动核单突触胞外场电位和单突触CM兴奋。然而，损伤后仍存在双突触抽动、双突触场电位和由C-3-C-4固有脊髓神经元介导的双突触CM兴奋。因此，损伤阻断了由前肢节段中间神经元介导的单突触CM通路和寡突触LC ST通路。术后1~28d观察握力和IFMS的变化。在3个月的观察期内，力量的减弱和预成型的缺陷仍然存在。间接的CM通路可能对神经康复很重要。
It is generally accepted that the precision grip and independent finger movements (IFMs) in monkey and man are controlled by the direct (monosynaptic) corticomotoneuronal (CM) pathway. This view is based on previous observations that pyramidotomy causes near permanent deficits of IFMs. However, in addition to the direct CM pathway, pyramidotomy interrupts several corticofugal connections to the brain stem and upper cervical segments. Indirect (oligosynaptic) CM pathways, which are phylogenetically older, have been considered to be of little or no importance in prehension. In three adult macaque monkeys, complete transection of the direct CM pathway was made in C-4/C-5, which is rostral to the forelimb segments (C-6-Th-1). Electrophysiological recordings revealed lack of the direct lateral corticospinal tract (LCST) volley, monosynaptic extracellular field potentials in the motor nuclei, and monosynaptic CM excitation. However, a disynaptic volley, disynaptic field potentials and disynaptic CM excitation mediated via C-3-C-4 propriospinal neurons remained after the lesion. Thus the lesion interrupted the monosynaptic CM pathway and oligosynaptic LCST pathways mediated by interneurons in the forelimb segments. Precision grip and IFMs were observed already after 1-28 days postoperatively. Weakness in force and deficits in preshaping remained for an observation period of 3 mo. Indirect CM pathways may be important for neuro-rehabilitation.