Hori Y, Watanabe S
Neurosci Lett. 1987 Jul 9;78(1):91-6. doi: 10.1016/0304-3940(87)90567-2.
The 8-15-day-old rat spinal cord was isolated together with peripheral nerves innervating a hindlimb. Multiunit neural discharges in response to electrical stimulation of a cutaneous nerve (sural, plantar of superficial peroneal nerve) were recorded from a flexor nerve (deep peroneal nerve or nerve innervating the hamstring muscles). Attempts were made to find relations between the magnitude of the flexion reflex discharges and the sizes of the volleys in the myelinated or unmyelinated afferent fibers. The neonatal flexion reflex discharges due to myelinated fiber volleys were exaggerated when compared with those in the adult rats. Higher stimulus strengths recruited later components of the flexion reflex discharges. The observed increment of the flexion reflex discharges was precisely associated with the recruitment of unmyelinated afferent fibers in the nerve. These late flexion reflex discharges were shown to be depressed by the opiate analgesic morphine in a naloxone-reversible manner.
将8至15日龄大鼠的脊髓连同支配后肢的外周神经一起分离出来。从屈肌神经（腓深神经或支配腘绳肌的神经）记录对皮神经（腓肠神经、足底神经或腓浅神经）进行电刺激时的多单位神经放电。试图找出屈肌反射放电的大小与有髓或无髓传入纤维中冲动群大小之间的关系。与成年大鼠相比，由有髓纤维冲动群引起的新生大鼠屈肌反射放电有所增强。更高的刺激强度会募集屈肌反射放电的后期成分。观察到的屈肌反射放电增加与神经中无髓传入纤维的募集精确相关。这些后期的屈肌反射放电被阿片类镇痛药吗啡以纳洛酮可逆的方式抑制。
