刺激大鼠离断背根外周端对相邻背根电活动的影响

在切断大鼠左侧１２、１３背根后,观察电刺激（刺激参数为０．８－１．２ｍＡ,１００Ｈｚ,０．５ｍｓ,总时程２ｓ）Ｌ２背根外同对Ｌ３背根放电活动的影响。结果表明：连续多次刺激Ｌ２背根可使Ｌ３背根平均放电频率（ＭＤＦ）逐步增加,增加量与刺激次数中于明显直线正相关,各次刺激后的时程分析表明,这种增频作用具有明显的累积效应的后效应,并与刺激前１３背根的活动状态密切相关,刺激前放电活动较强者其增频作用更明显。

Effect of stimulating the peripheral endings of transected dorsal root on discharges of neighbouring dorsal root in rats

The dorsal roots (DR) of L2-L3 segments on the left side in anesthetized rats (n = 28) were exposed and transected. After stimulating the peripheral endings of L2 DR with a train of square waves (0.8-1.2 mA, 100 Hz, 0.5 ms) for 2 s, the discharges at the distal end of transected L3 DR were recorded for 120 s. We found that the mean discharge frequency (MDF) of L3 DR was gradually increased with L2 DR stimulation. Time course analysis showed that the increase in MDF was linearly correlative to the number of stimuli, as well as to the levels of spontaneous discharge of L3 DR. The above results suggest that the transegmental information transmission between peripheral endings of primary sensory neurons may occur through a chemical non-synaptic way.