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? Objective To observe whether the primary afferent fibers of Aβ participate in the inter-segment transmission of peripheral nerve endings to explore the mechanism of pathological transmission.Methods The peripheral dorsal cutaneous branches of the T9 and T1 0 spinal nerves distributed through the solar bladder were separated, Near the midpoint of the cut off, the distal midpoint of one of the severed nerves was separated into several fine bundles, recording the discharge of individual Aβ fibers on each branch and applying a reverse electrical stimulation to the distal mid-section of the other severed nerve , That is, across the segment electrical stimulation (0.45m A, 0. 1ms, 20 Hz, for 1 0 s), to observe the changes of electrical discharge across the segmental changes in order to analyze the relationship between the cut off central nervous system peripheral nerve endings Whether there was cross-sectional information transmission.Results 50 Aβ primary afferent fibers were recorded in 40 rats.After cross-sectional electrical stimulation, 50.0% (2 5 / 50), the discharge of Aβ fibers significantly and transiently increased. The mean discharge time was significantly increased from 0 to 30 s after stimulation (P <0.01) and reached the peak at 30 to 60 s, which was later than that of C- Class A and Aβ fibers appeared 30 s after which the discharge decreased rapidly and returned to the control level after 60 s. The number of discharges at 0 to 30 s and 30 to 60 s after the electrical stimulation increased from 1 .65 ± 0.14 to 1.12 ± 0.18 and 1.20 ± 0 respectively from the control. The number of discharges increased more in Aβs than those in Aβs and slower in Aβs.Conclusion Aβ fibers can be activated by cross-sectional electrical stimulation, showing an increase in discharge.The peak of discharge increase is higher than that of C fibers and Aβ fiber delay 30 s, the duration of the increase is also more than these two types of fiber?