Caza P A, Spear L P
Pharmacol Biochem Behav. 1980 Jul;13(1):45-50. doi: 10.1016/0091-3057(80)90119-7.
Ten, seventeen and twenty-four day old rats were observed using a behavioral-time sampling procedure following injection of saline, 0.1, 0.5, 1.0 or 5.0 mg/kg/5cc morphine sulphate. At Day 10, the predominant response to morphine was a depression of locomotor activity. At the 5 mg/kg dose, catalepsy was also seen. In animals of this age, 0.1 mg/kg morphine, which was not sufficient to depress activity, also had no effect on stereotyped gnawing/mouthing behavior, nor did it produce any increase in locomotor activity. A morphine-induced increase in locomotion was first seen on Day 17 (after 0.5 mg/kg morphine). As with Day 10 animals, Day 17 animals given 5 mg/kg morphine showed a depression of locomotion and catalepsy. Stereotypic gnawing/mouthing behavior was first seen in Day 24 animals (after 5 mg/kg morphine), although no dose of morphine produced significant differences in activity at this age. Possible mechanisms resulting in these marked alterations in behavioral response patterns to morphine during this two week period of ontogeny are discussed.
在给10日龄、17日龄和24日龄的大鼠注射生理盐水、0.1、0.5、1.0或5.0毫克/千克/5毫升硫酸吗啡后，采用行为定时抽样程序对其进行观察。在第10天，对吗啡的主要反应是运动活动受到抑制。在5毫克/千克的剂量下，还观察到了僵住症。在这个年龄段的动物中，0.1毫克/千克的吗啡不足以抑制活动，对刻板啃咬/张嘴行为也没有影响，也不会使运动活动增加。吗啡诱导的运动增加首次出现在第17天（0.5毫克/千克吗啡注射后）。与第10天的动物一样，注射5毫克/千克吗啡的第17天动物表现出运动抑制和僵住症。刻板啃咬/张嘴行为首次出现在第24天的动物中（5毫克/千克吗啡注射后），尽管在这个年龄段没有任何剂量的吗啡会使活动产生显著差异。本文讨论了在这两周个体发育期间导致对吗啡行为反应模式出现这些显著变化的可能机制。
