Keifer J, Houk J C
Department of Physiology, Northwestern University Medical School, Chicago, IL 60611.
Brain Res. 1993 Apr 16;608(2):349-52. doi: 10.1016/0006-8993(93)91478-b.
Burst discharges in the red nucleus are correlated with discrete limb movements. Intracellular recordings from red nucleus neurons in the in vitro turtle brainstem-cerebellum was performed to elucidate mechanisms underlying these bursts. Depolarizing intracellular current injection failed to demonstrate endogenous membrane currents that might produce burst discharges, and neurons did not exhibit significant spike frequency adaptation, which is a characteristic of synaptically driven bursts. Responses of red nucleus neurons to synaptic input demonstrated a late, slow depolarizing synaptic potential (slow EPSP) having a latency of 9-12 ms, and a maximal duration of 600 ms. it is concluded that neither intrinsic membrane responses, nor the duration of the slow EPSP, can fully account for the behavior of red nucleus neurons during burst discharge. We hypothesize that activity in the red nucleus is driven by a gradual recruitment of NMDA receptors, and lpr by polysynaptic excitatory pathways.
红核中的爆发性放电与离散的肢体运动相关。在体外龟脑干-小脑的红核神经元上进行细胞内记录，以阐明这些爆发背后的机制。去极化细胞内电流注入未能证明可能产生爆发性放电的内源性膜电流，并且神经元未表现出明显的放电频率适应性，而这是突触驱动爆发的一个特征。红核神经元对突触输入的反应表现出一种延迟的、缓慢去极化的突触电位（慢兴奋性突触后电位），潜伏期为9 - 12毫秒，最大持续时间为600毫秒。得出的结论是，无论是内在膜反应还是慢兴奋性突触后电位的持续时间，都不能完全解释爆发性放电期间红核神经元的行为。我们假设红核中的活动是由NMDA受体的逐渐募集以及多突触兴奋性通路驱动的。
