摘要
为确定参与外周神经末梢之间跨节段信息传递的纤维类别 ,实验采用在脊神经背侧皮支上分离细束的方法 ,观察了电刺激相邻脊髓节段皮神经对C类机械感受单位传入放电的影响。结果发现 ,87 5 % (3 5 /4 0 )的慢适应和 5 0 % (5 /1 0 )的快适应C类机械感受单位在刺激后 90sec内放电频率显著增加 ,以 3 0sec内放电增加最为显著 (P <0 0 0 1 )。对机械刺激后放电越长的单位以及慢适应单位更容易被跨节段电刺激激活。感觉单位的自发放电频率与其对跨节段电刺激的反应无关。结果提示 ,C类纤维参与了外周神经末梢之间的跨节段信息传递 ,这可能是循经感传发生的神经生物学基础之一。
Objective: To determine the fiber type participating in the peripharal information transmission across nerve segments. Methods: Experiments were performed on SD rats anesthetized with intraperitoneal injection of 20% urethane 1 g/kg. The dorsal cutaneous branches of T 9 and T 10 spinal nerves innervating “Ganshu' (BL 18), and “Danshu”(BL 19)of the Pangguang Meridian of Foot Taiyang were freed and cut proximally. The C fiber endings capable of responding to mechanical stimuli were obtained by isolating nerve filaments on the dorsal cutaneous branch of T 10 spinal nerve. Those filaments responding to hair brushing, von Frey's hair pressing were subjected into this study. The dorsal cutaneous nerve of T 9 was antidromically stimulated with single electric pulses. Firing signals were processed with sequential density histograms. Results: It was found that 87.5% (35/40) of the slow adapting units and 50%(5/10) of the fast adapting units of the C fiber endings fired more actively within the first 90 sec after the stimulation, particularly within the first 30 ecs (P<0.001). Slow adapting units and those having a longer after discharge were prone to be activated by electrical stimulation of the adjacent spinal segments. There was no correlation between the spontaneous discharge frequency of unit and its response to the stimulation. Conclusion: These results suggest that the C fibers participate in the information transmission across spinal segments between the peripheral endings, which may contribute to the phenomenon of the sensory conduction along channels.
出处
《针刺研究》
CAS
CSCD
2001年第1期5-9,共5页
Acupuncture Research
基金
"九.五"国家攀登计划资助项目!(95 预 19 131)
