Iijima Y, Shinoda M, Kuribara H, Asami T, Uchihashi Y
Department of Neuropsychiatry, Gunma University School of Medicine, Maebashi, Japan.
Nihon Shinkei Seishin Yakurigaku Zasshi. 1995 Aug;15(4):315-21.
The effects of cocaine on wheel-running and drinking activities in mice, housed under a 12-h light-dark schedule (lighted period; 6:00-18:00 h), were investigated through long continuous observation. Cocaine (20 and 40 mg/kg, sc), administered at 11:00 h, acutely increased wheel-running and drinking, but it was followed by a sub-acute suppression of the spontaneous increment in both of these behaviors during the coming dark period (18:00-6:00 h). Such behavioral accelerating and suppressing effects of cocaine did not change throughout the whole course of administration, which was repeated five times at 3- to 5-day intervals. In addition to these findings, wheel-running and drinking spontaneously increased during the light period and decreased during the dark period on the day after the drug administration. On the other hand, the repeated administration of cocaine at 18:00 h never increased, but rather acutely suppressed both behaviors during the dark period, and no trends in the behavioral changes on the next day were clearly shown. These results suggest that the effects of cocaine on wheel-running and drinking differ depending on the time of day of the administration.
通过长期连续观察，研究了可卡因对处于12小时光照-黑暗周期（光照期为6:00-18:00 h）饲养的小鼠的转轮和饮水活动的影响。于11:00 h皮下注射可卡因（20和40 mg/kg），可急性增加转轮和饮水行为，但随后在接下来的黑暗期（18:00-6:00 h）这两种行为的自发增加受到亚急性抑制。可卡因的这种行为促进和抑制作用在整个给药过程中没有变化，给药过程以3至5天的间隔重复进行了五次。除了这些发现外，在给药后的第二天，转轮和饮水行为在光照期自发增加，在黑暗期减少。另一方面，在18:00 h重复注射可卡因从未增加，反而在黑暗期急性抑制了这两种行为，并且在第二天没有明显显示出行为变化的趋势。这些结果表明，可卡因对转轮和饮水的影响因给药时间的不同而有所差异。
