Effects of preventing reinnervation on axotomized spinal motoneurons in the cat. II. Changes in group Ia synaptic function.
Effects of preventing reinnervation on axotomized spinal motoneurons in the cat. II. Changes in group Ia synaptic function.
复制标题
防止猫轴突脊髓运动神经元重新支配的影响。
DOI：
10.1152/jn.1989.62.2.325
复制
发表时间：
1989
影响因子：
2.5
通讯作者：
Pinter,MJ
中科院分区：
文献类型：
--
作者：
VandenNoven,S;Pinter,MJ
1. 我们研究了异源性Ia组传入事件电刺激引起的复合兴奋性突触后电位（EPSPs）在不同的术后时间，在被剥夺再神经支配肌肉的机会的axoized运动神经元中。2. 横断内侧腓肠肌（MG）神经并将其缝合到正常支配的外侧腓肠肌（LG）肌表面。切除失神经的MG肌，从而消除了再生的MG运动轴突到空终板的通路。3. 电刺激LGS -比目鱼神经（LGS）引起的单突触Ia EPSPs平均振幅在术后20天（DPO）开始下降，但不显著。在44 DPO时，平均振幅显著下降至对照平均振幅的43%。在90 DPO时，平均EPSP振幅与对照组无显著差异。在最晚的术后时间（150-180 DPO），平均振幅明显小于对照振幅。4. 术后早期（20-44 DPO）平均EPSP上升时间（至峰值时间）显著增加（27%）。术后后期（90-180），EPSP平均上升时间与对照组平均上升时间无显著差异。5. 术后未观察到epsp叠加的“部分反应”。6. LGS EPSP的平均破伤风后增强（PTP）在20 DPO时显著降低。在术后后期，PTP与平均对照PTP无显著差异。7. 这种可能性被认为是运动神经元电性质的改变可以解释这些复杂的平均EPSP振幅和上升时间的变化。
1. Composite excitatory postsynaptic potentials (EPSPs) evoked by electrical stimulation of heteronymous group Ia afferents have been studied at various postoperative times in axotomized motoneurons that were denied the opportunity to reinnervate muscle. 2. The medial gastrocnemius (MG) nerve was transected and sutured onto the surface of the normally innervated lateral gastrocnemius (LG) muscle. The denervated MG muscle was excised thereby eliminating access of regenerating MG motor axons to vacant end-plates. 3. The mean amplitude of monosynaptic Ia EPSPs evoked by electrical stimulation of the LG-soleus (LGS) nerve and recorded in axotomized MG motoneurons showed an initial decline at 20 days postoperative (DPO) that was not significant. At 44 DPO, mean amplitude had declined significantly to 43% of the control mean amplitude. At 90 DPO, mean EPSP amplitude was not significantly different from control. At the latest postoperative time (150-180 DPO), mean amplitude was significantly less than the control amplitude. 4. Mean EPSP rise time (time-to-peak) was significantly increased (27%) at the earliest postoperative times (20-44 DPO). At later postoperative times (90-180), mean EPSP rise time was not significantly different from mean control rise time. 5. "Partial responses" superimposed on EPSPs were not observed at any postoperative time. 6. Mean posttetanic potentiation (PTP) of the LGS EPSP was significantly depressed at 20 DPO. At later postoperative times, PTP did not differ significantly from mean control PTP. 7. The possibility is considered that postaxotomy alterations in the electrical properties of motoneurons may explain these complex variations of mean EPSP amplitude and rise time.