电刺激大鼠外侧缰核对延髓甩尾相关细胞的活动和甩尾反射的影响

在浅麻醉大鼠上，在延髓腹内侧结构内观察到三种具有不同放电类型的细胞，即乃尾前放电骤停的撤反应细胞，甩尾前放电骤增的给反应细胞和甩尾无关的中性细胞。电刺激外侧缰核可抑制撤反应细胞的自发放电，加强给反应细胞自发放电，从而易化两类细胞的甩尾相关反应，同时易化伤害刺激引起的甩尾反射。实验结果说明，外侧缰核对节段性防御反射有易化作用，这种易化作用可能是通过延髓内撤反应和反应细胞的协同活动而实现的。

INVOLVEMENT OF MEDULLARY TALK-FLICK RELATED NEURONS IN THE DESCENDING FACILITATING EFFECTS EVOKED BY STIMULATION OF LATERAL HABENULAR NUCLEUS

In lightly anesthetized rats 3 classes of neurons in the rostral ventromedial medulla (RVM) were in relation to tail-flick reflex (TF) recorded, i. e. the TF triggired onceds, the TF triggered off-cells and the non-responsive or neutral cells. When lateral habenular nucleus (LHb) was stimulated the on-cells were excited, the off-cells inhibited while the neutral cells unaffected. The fact that stimulation of LHb facilitated tailflick reflex appears to be quite well explained by its enhancement effect on the tail-flick related response of both the on- and the off-cells. These results indicate that the facilitating action of LHb on spinal defensive reflex is probably brought out by participation of the medullary tail-flick related cell activity.