Dietz David, Wang Hui, Kabbaj Mohamed
Florida State University, College of Medicine, Department of Biomedical Sciences, Program in Neuroscience, Tallahassee, FL 32306-4300, United States.
Behav Brain Res. 2007 Aug 6;181(2):287-91. doi: 10.1016/j.bbr.2007.04.005. Epub 2007 Apr 20.
In some rats, the hormone corticosterone is reinforcing. High novelty-seeking rats (high responders, HR) self-administered corticosterone at a much higher rate than low novelty-seeking rats (low responders, LR) do [Piazza PV, Deroche V, Deminiere JM, Maccari S, Le Moal M, Simon H, Corticosterone in the range of stress-induced levels possesses reinforcing properties: implications for sensation-seeking behaviors, Proc Natl Acad Sci USA 1993;90:11738-42]. While previous studies demonstrated that corticosterone reinforces nose poking in a self-administration paradigm, no studies to date have examined whether corticosterone is rewarding.
Using the conditioned place preference (CPP) paradigm, we examined the rewarding effects of corticosterone in HR and LR rats.
Male Sprague-Dawley rats were classified into HR and LR groups based on their locomotor activity in a novel environment. Subsequently, independent groups of HR and LR rats underwent CPP for corticosterone (0, 2.5 or 10 mg/kg; i.p.) or cocaine (12 mg/kg; i.p). CPP for cocaine was used as a positive control.
While cocaine produced a strong CPP in both HR and LR rats, corticosterone failed to produce either preference or aversion in both phenotypes.
Corticosterone is neither rewarding nor aversive in either behavioral phenotype.
在一些大鼠中，皮质酮这种激素具有强化作用。高新奇寻求型大鼠（高反应者，HR）自我给药皮质酮的速率比低新奇寻求型大鼠（低反应者，LR）高得多[皮耶扎PV，德罗什V，德米尼埃JM，马卡里S，勒莫阿M，西蒙H，应激诱导水平范围内的皮质酮具有强化特性：对寻求感觉行为的影响，《美国国家科学院院刊》1993年；90：11738 - 42]。虽然先前的研究表明皮质酮在自我给药范式中强化了鼻触行为，但迄今为止尚无研究考察皮质酮是否具有奖赏性。
使用条件性位置偏爱（CPP）范式，我们研究了皮质酮对HR和LR大鼠的奖赏作用。
将雄性斯普拉格 - 道利大鼠根据其在新环境中的运动活动分为HR组和LR组。随后，HR和LR大鼠的独立组接受了针对皮质酮（0、2.5或10毫克/千克；腹腔注射）或可卡因（12毫克/千克；腹腔注射）的CPP实验。针对可卡因的CPP实验用作阳性对照。
虽然可卡因在HR和LR大鼠中均产生了强烈的CPP，但皮质酮在两种表型中均未产生偏爱或厌恶。
皮质酮在两种行为表型中既无奖赏性也无厌恶性。
