Guevremont Lisa, Renzi Costantino G, Norton Jonathan A, Kowalczewski Jan, Saigal Rajiv, Mushahwar Vivian K
Department of Biomedical Engineering, University of Alberta, Edmonton, AB T6G 2V2, Canada.
IEEE Trans Neural Syst Rehabil Eng. 2006 Sep;14(3):266-72. doi: 10.1109/TNSRE.2006.881592.
It is commonly accepted that locomotor-related neuronal circuitry resides in the lumbosacral spinal cord. Pharmacological agents, epidural electrical stimulation, and sensory stimulation can be used to activate these instrinsic networks in in vitro neonatal rat and in vivo cat preparations. In this study, we investigated the use of low-level tonic intraspinal microstimulation (ISMS) as a means of activating spinal locomotor networks in adult cats with complete spinal transections. Trains of low-amplitude electrical pulses were delivered to the spinal cord via groups of fine microwires implanted in the ventral horns of the lumbosacral enlargement. In contrast to published reports, tonic ISMS applied through microwires in the caudal regions of the lumbosacral enlargement (L7-S1) was more effective in eliciting alternating movements in the hindlimbs than stimulation in the rostral regions. Possible mechanisms of action of tonic ISMS include depolarization of locally oscillating networks in the lumbosacral cord, backfiring of primary afferents, or activation of propriospinal neurons.
人们普遍认为，与运动相关的神经回路存在于腰骶脊髓中。药物、硬膜外电刺激和感觉刺激可用于在新生大鼠体外和猫体内制备中激活这些内在网络。在本研究中，我们研究了使用低水平强直性脊髓内微刺激（ISMS）作为激活完全脊髓横断成年猫脊髓运动网络的一种方法。通过植入腰骶膨大腹角的细微丝组将低振幅电脉冲串传递到脊髓。与已发表的报告相反，通过腰骶膨大（L7-S1）尾侧区域的微丝施加的强直性ISMS在后肢诱发交替运动方面比在头侧区域的刺激更有效。强直性ISMS的可能作用机制包括腰骶脊髓中局部振荡网络的去极化、初级传入神经的逆向放电或脊髓 propriospinal 神经元的激活。
