大鼠延髓头端腹内侧区甩尾相关神经元在电针镇痛中的可能作用

THE ACTION OF MEDULLARY TAIL-FLICK RELATED NEURONS IN ELECTROACUPUNCTURE ANALGESIA

在浅麻醉状态下的大鼠,用辐射热烫尾并同步记录延髓头端腹内侧区神经元单位放电,按紧随甩尾动作发生前细胞放电频率的变化而将其分为甩尾前放电骤停的撤型细胞,放电骤增的给型细胞和无变化的中性细胞。电针双侧“次髎”穴引起动物甩尾反射抑制时,撤型细胞自发放电增加,与电针前相比差异显著(P<0.001),给型细胞电针后自发放电频率的改变与电针前相比无显著差异(P>0.05),两类细胞的甩尾相关反应均被抑制。结果提示:撤型细胞可能是延髓头端腹内侧区参与针刺镇痛的主要传出神经元。

Three types of cells, i. e, off-neurons, on--neurons and neutral neurons, could berecorded in the rostral ventromedial medulla (RVM) in light anethetized rats. Just pri-or to the occurrence of tail flick elicited by noxious heat, the on--cells showed a burst ofactivity while the off-cells exhibited a cessation of discharge. No.change of neutral cellactivity related to tail flick was otherved. Electroacupuncture at two 'Ci Liao' pointswhich resulted in inhibition of tail-flick reflex affected the spontaneous activity of off-and on-cells in a different way, i. e, the discharge of most off--cells was significantlyincreased (P<0.001), while that of on-cells showed no obvious change (P>05).Tail--flick related responses of the both cells were inhibited. These results provide the ev-idence that the off-cells may be the main efferent neurons in RVM involving in elec-troacupuncture analgesia.