3跨节段电刺激引起的大鼠脊神经背侧皮支中 Aβ类初级传入纤维放电的改变(英文)  

Discharge changes of Aβ-fibers of the dorsal cutaneous branch in spinal nerve evoked by electrical stimulation of adjacent spinal segments

作　　者：孙启新[1] 赵晏[2] 张世红[2] 史文春[2] 王会生[2] 

机构地区：[1]西安交通大学生命科学与技术学院生物医学工程系,陕西西安710049 [2]西安交通大学医学院神经生物学研究中心,陕西西安710049

出　　处：《第四军医大学学报》2002年第1期23-27,共5页Journal of the Fourth Military Medical University

基　　金：National Clim bing Plan of China(95- 19- 13 1)

摘　　要：目的　观察 Aβ类初级传入纤维是否参与外周神经末梢间的跨节段信息传递以探讨循径感传的机制 .方法　分离循足太阳膀胱经分布的 T9和 T1 0脊神经背侧皮支 ,并于近中端切断 ,将一支切断神经的远中端分离成数支细束 ,分别记录每一支上的单个 Aβ类纤维的放电 ,在另一支切断神经的远中端上施加逆向电刺激 ,即跨节段电刺激 (0 .45m A,0 .1ms,2 0 Hz,for 1 0 s) ,观察跨节段电刺激后放电的改变 ,以分析切断中枢神经系统联系后外周神经末梢间是否存在跨节段信息传递 .结果　在 40只大鼠上共记录了 50个 Aβ类初级传入纤维 .跨节段电刺激后 ,相邻脊髓节段皮神经上 50 .0 %(2 5/ 50 )的 Aβ类纤维的放电显著而短暂增加 ,放电均数在刺激后 0～ 30 s即显著高于对照 (P<0 .0 1 ) ,30～ 60 s达到高峰 ,该峰晚于 C-类和 Aβ类纤维的 30 s出现 .此后放电迅速下降 ,60 s后恢复到对照水平 .跨节段电刺激后 0～ 30 s和30～ 60 s的放电数从对照的每 30 s 0 .65± 0 .1 4分别上升到1 .1 2± 0 .1 8和 1 .2 0± 0 .31 .放电数的增加更多见于慢适应Aβ类和传导速度较慢的 Aβ类单位 .结论　 Aβ类纤维可被跨节段电刺激激活 ,表现为放电增加 .放电增加的高峰比 C类纤维和 Aβ类纤维延迟 30 s,持续增加的时程也比这两类纤维的?AIM To observe whether the primary afferent Aβ fiber is involved in the information transmission across spinal segments and to investigate the mechanism of sensory transmission along meridian. METHODS The dorsal cutaneous nerve branches of spinal nerves from T 9 and T 10 segments were cut proximally distributing along Bladder Meridian of Foot Taiyang (BL). One peripheral end of the cut nerves was dissected into a few filaments for recording the discharge of single Aβ fibers while the other one peripheral end of the cut nerves was applied antidromically electrical stimulation to observe the discharge change of single Aβ unit and to analyze if information transmission between endings of peripheral nerves appear without communication of center nerve system. RESULTS 50 Aβ units were recorded in 40 rats. After an electrical stimulation (0.45 mA, 0.1 ms, 20 Hz, for 10 s) was delivered to the stimulated nerve, the discharge number of 50.0% (25/50) Aβ fibers in cutaneous nerve of adjacent spinal segment was found to have a remarkable but transient increase. The discharge number per 30 s of all Aβ fibers reached maximum in 30~60 s, 30 s later than that of C and Aβ fibers, and then, declined and returned to its control level 60 s after the electrical stimulation across spinal segments. The discharge numbers of the units in creased to 1.12±0.18 and 1.20±0.31 respectively from 0.68 ±0.14, its control value per 30 s during 0~30 s and 30~ 60 s after the stimulation ( P <0.01). The duration of discharge increase was 30 s shorter than that of C and Aβ fibers. CONCLUSION The firing of Aβ fibers can be activated by the antidromically electrical stimulation to cutaneous nerve of adjacent spinal segment, which indicates that the information transmission occurs between two endings of peripheral afferent nerves from adjacent spinal segments,and Aβ fibers participate in the process of information transmission across spinal segments.

关 键 词：Aβ类初级传入纤维 电刺激 跨节段信息传递 循经感传 

分 类 号：R338.1[医药卫生—人体生理学]