Deshpande S B, Warnick J E
Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, Baltimore 21201.
Neuropharmacology. 1988 Oct;27(10):1033-7. doi: 10.1016/0028-3908(88)90064-0.
The amplitude, latency and rise time of the monosynaptic reflex, recorded from the spinal cord of the neonatal rat in vitro, was temperature-dependent with optimal conditions occurring at 25 degrees C. The reflex was inhibited when conditioning stimuli were applied to an adjacent dorsal root at 1-150 msec before the monosynaptic reflex was evoked; the inhibition had both an early and a late phase. The early phase of inhibition occurred at conditioning-test intervals of 1-20 msec with peak inhibition occurring at 7 msec. Raising the temperature of the bath to 31 degrees C or exposing the cord to strychnine blocked the early phase of inhibition. The late phase of inhibition occurred at conditioning-test intervals greater than 20 msec, was unaffected by temperature and was blocked by bicuculline. The early phase of inhibition therefore appears to be postsynaptic in origin and mediated by glycine while the late component of inhibition may be presynaptic in origin and mediated by gamma-aminobutyric acid (GABA).
在新生大鼠脊髓体外记录的单突触反射的波幅、潜伏期和上升时间与温度有关，最适条件出现在25摄氏度。当在诱发单突触反射前1 - 150毫秒对相邻背根施加条件刺激时，反射受到抑制；这种抑制有早期和晚期两个阶段。抑制的早期阶段出现在条件刺激 - 测试刺激间隔为1 - 20毫秒时，在7毫秒时出现最大抑制。将浴温升至31摄氏度或使脊髓暴露于士的宁会阻断抑制的早期阶段。抑制的晚期阶段出现在条件刺激 - 测试刺激间隔大于20毫秒时，不受温度影响，并被荷包牡丹碱阻断。因此，抑制的早期阶段似乎起源于突触后，由甘氨酸介导，而抑制的晚期成分可能起源于突触前，由γ - 氨基丁酸（GABA）介导。
