Schouenborg J, Dickenson A
Brain Res. 1985 Feb 25;328(1):23-32. doi: 10.1016/0006-8993(85)91318-6.
In the halothane-anaesthetized rat, the responses of 49 neurons in the lumbo-sacral cord and the reflex discharge in the common peroneal nerve following electrical stimulation of the sural nerve were recorded in order to study possible relations between neuronal events and reflex nerve discharges. A distant noxious stimulus (to activate Diffuse Noxious Inhibitory Controls (DNIC) of Le Bars et al.) was used as a conditioning stimulus. Only the responses of neurons receiving an input from both A and C fibres were studied. The neurons were classified as class 1 (low threshold mechanoreceptive input only, n = 2), class 2 (nonnoxious and noxious inputs, n = 34) or class 3 (responding to noxious stimuli only, n = 13). During conditioning stimulation the C fibre evoked discharge was inhibited in 32 out of 34 class 2 neurons. The A fibre-evoked discharge was simultaneously inhibited in 29 of these neurons. The main effect of the distant noxious stimulation on the C fibre evoked neuronal discharge was to decrease the discharge by a constant number of spikes, independent of the level of evoked activity. Only one class 3 neuron was inhibited during conditioning stimulation and none of the class 1 cells were influenced by DNIC. During conditioning stimulation the late and prolonged C fibre evoked reflex nerve discharge (latency 160-200 ms, duration up to several hundred ms) was strongly depressed. Concomitantly, a short-lasting reflex nerve discharge appeared over the interval 115-160 ms. This released reflex nerve discharge (RR) had a constant latency. There was no simultaneous change of the A beta evoked reflex nerve discharge. After the end of the distant noxious stimulation the late C fibre evoked reflex nerve discharge (latency 160-200 ms) recovered. Concomitantly, the RR disappeared. The possibility that the class 2 neurons and the class 3 neurons are intercalated in different reflex pathways is discussed.
在氟烷麻醉的大鼠中，记录了腰-骶髓中49个神经元的反应以及电刺激腓肠神经后腓总神经的反射放电，以研究神经元活动与反射神经放电之间的可能关系。使用远处的有害刺激（以激活勒巴尔等人提出的弥漫性有害抑制控制（DNIC））作为条件刺激。仅研究了接受A纤维和C纤维输入的神经元的反应。这些神经元被分为1类（仅低阈值机械感受性输入，n = 2）、2类（无害和有害输入，n = 34）或3类（仅对有害刺激有反应，n = 13）。在条件刺激期间，34个2类神经元中有32个的C纤维诱发放电受到抑制。其中29个神经元的A纤维诱发放电同时受到抑制。远处有害刺激对C纤维诱发的神经元放电的主要作用是使放电减少固定数量的峰电位，与诱发活动水平无关。在条件刺激期间，仅1个3类神经元受到抑制，1类细胞均未受DNIC影响。在条件刺激期间，晚期且持续时间长的C纤维诱发的反射神经放电（潜伏期160 - 200毫秒，持续时间长达数百毫秒）受到强烈抑制。与此同时，在115 - 160毫秒的间隔内出现了短暂的反射神经放电。这种释放的反射神经放电（RR）具有恒定的潜伏期。Aβ诱发的反射神经放电没有同时发生变化。远处有害刺激结束后，晚期C纤维诱发的反射神经放电（潜伏期160 - 200毫秒）恢复。与此同时，RR消失。文中讨论了2类神经元和3类神经元插入不同反射通路的可能性。
