小鼠新颖寻求特质对酒精的运动激活效应的影响

The Influence of Novelty Seeking Behavioral Trait on Ethanol Induced Stimulatory Effects in Mice

新颖寻求(或感觉寻求)特质与许多成瘾药物的易感性密切相关。例如,高、低新颖寻求动物对可卡因、苯丙胺和吗啡等成瘾药物的奖赏、运动激活、强化效应的反应存在差异。长期饮用酒精也容易成瘾,但尚未发现关于新颖寻求特质影响酒精成瘾的报道。本实验采用药物成瘾研究中常用的自发活动模型,考察了高、低新颖寻求动物在酒精急性处理、慢性处理和激发过程中的行为表现。实验过程中首先采用两种新颖寻求模型,即新颖环境中自发活动模型和新颖客体偏爱模型,将昆明小鼠分别区分为高、低自发活动组和高、低新颖客体偏爱组,连续10天给予酒精(2g/kg/d,i.p.)或等量盐水处理,戒断2天后所有小鼠接受酒精(2g/kg)激发。实验结果表明,新颖环境低自发活动小鼠比新颖环境高自发活动小鼠对酒精急性、慢性处理导致的运动激活效应更敏感;在酒精激发期前者的自发活动水平也高于后者。本实验结果说明新颖环境中自发活动特质影响动物对酒精导致的运动激活效应的反应。

Novelty seeking or sensation seeking is often associated with susceptibility to substance abuse.In preclinical studies,high and low novelty seeking animals show different sensitivities to locomotor stimulating,rewarding and reinforcing effects of drugs of abuse,such as cocaine,amphetamine and morphine.It is well known that chronic alcohol consumption can result in alcoholism;however,little is known about the relationship between novelty seeking behavioral trait and propensity to alcoholism.The present study examined the relationship between novelty seeking and the response to acute or repeated ethanol treatment using locomotor activity as the behavioral endpoint.Adult male KM mice were categorized as HR（high responders in novel environment） and LR（low responders in novel environment）,or HOP（high object preference） and LOP（low object preference） based on their activities in a novel environment and novel object preference.After baseline activity measurements,subjects were tested daily after i.p.injections of either ethanol（2g/kg/d） or saline for 10 days.Two days later,ethanol（2g/kg） was re-tested in all animals.LR mice were more sensitive than HR mice to acute and chronic ethanol induced hyperactivity.When challenged with ethanol 2 days after repeated ethanol treatment,the locomotor stimulating effect of ethanol was more robust in LR mice than in HR mice.No such difference was observed in HOP mice and LOP mice.In conclusion,locomotor activity in a novel environment may predict the locomotor stimulating effects of ethanol in KM mice.