Collins J G
Brain Res. 1987 Jan 13;401(1):95-102. doi: 10.1016/0006-8993(87)91168-1.
Low-threshold neurons in the dorsal horn of the spinal cord of physiologically intact, awake, drug-free cats demonstrate minimal rates of spontaneous activity. Studies in acute animals suggest that the lack of spontaneous activity is due to descending inhibitory control mechanisms. The present study suggests that the inhibition of spontaneous activity is naloxone-insensitive. Intravenously administered naloxone in doses of up to 0.4 mg/kg failed to have any effect on the spontaneous activity of the 34 low-threshold neurons recorded from the dorsal horn of the spinal cord of physiologically intact, awake animals. Stimulus-evoked activity was also not significantly influenced by the doses of naloxone used in this study. These results confirm data previously obtained by others using acute preparations. This confirmation is important in that it demonstrates that, for this system, differences between acute and chronic preparations do not appear to alter neuronal sensitivity to specific drug manipulations. They also verify that, for this system, acute experiments accurately reflect conditions that exist in the intact animal.
在生理状态正常、清醒且未用药的猫的脊髓背角中，低阈值神经元表现出极低的自发活动率。对急性实验动物的研究表明，缺乏自发活动是由于下行抑制控制机制。本研究表明，自发活动的抑制对纳洛酮不敏感。静脉注射高达0.4mg/kg剂量的纳洛酮，对从生理状态正常、清醒动物的脊髓背角记录到的34个低阈值神经元的自发活动没有任何影响。本研究中使用的纳洛酮剂量对刺激诱发的活动也没有显著影响。这些结果证实了其他人先前使用急性制备方法所获得的数据。这种证实很重要，因为它表明，对于这个系统，急性和慢性制备方法之间的差异似乎不会改变神经元对特定药物操作的敏感性。它们还证实，对于这个系统，急性实验准确地反映了完整动物体内存在的情况。
