Pelloux Yann, Costentin Jean, Duterte-Boucher Dominique
CNRS FRE 2735, Unité de Neuropsychopharmacologie Expérimentale, Institut Fédératif de Recherche Multidisciplinaire sur les Peptides, IFRMP 23, Faculté de Médecine et de Pharmacie de Rouen, 22, Bld Gambetta 76000 Rouen, France.
Pharmacol Biochem Behav. 2006 May;84(1):43-50. doi: 10.1016/j.pbb.2006.04.004. Epub 2006 Jun 2.
Sensation seeking is frequently observed among drug addicts. This behaviour has been modelled in non-primate animals as novelty seeking. We previously determined that novelty preference did not predict amphetamine-induced place conditioning but was positively correlated with the consumption of a low concentrated amphetamine solution. Here, we studied the relationship between novelty seeking and the vulnerability to rewarding and reinforcing effects of morphine. Wistar rats were selected according to their novelty preference. In this model, animals have free choice between a new compartment and a "familiar" compartment to which they were previously exposed during two 30-min sessions, 24 h apart. We measured oral morphine consumption when this drug was presented in tap water (25 or 50 mg/l) in free choice with water or when it was presented (50 mg/l) in a 5% (w/v) sucrose solution in free choice with a sucrose solution. The oral consumption of quinine was also measured. The rewarding effect of morphine (1.25 and 5 mg/kg; i.p.) was determined in a conditioned place preference paradigm. Whereas high and low novelty seekers did not differ in reactivity to the aversive taste of quinine, preference for novelty was associated with a greater oral morphine consumption as well as an increased conditioned place preference induced by the 5 mg/kg dose of morphine. The present results support the hypothesis that novelty preference predisposes to drug abuse.
在吸毒者中经常观察到寻求刺激的行为。这种行为在非灵长类动物中被模拟为寻求新奇。我们之前确定，新奇偏好并不能预测苯丙胺诱导的位置条件反射，但与低浓度苯丙胺溶液的消耗量呈正相关。在此，我们研究了寻求新奇与对吗啡奖赏和强化作用的易感性之间的关系。根据Wistar大鼠的新奇偏好进行选择。在这个模型中，动物可以在一个新的隔室和一个它们在之前两个30分钟的时间段（间隔24小时）内接触过的“熟悉”隔室之间自由选择。当吗啡以25或50毫克/升的浓度溶解在自来水中供其与水自由选择饮用，或者以50毫克/升的浓度溶解在5%（w/v）的蔗糖溶液中供其与蔗糖溶液自由选择饮用时，我们测量了大鼠口服吗啡的量。同时也测量了奎宁的口服量。在条件性位置偏好范式中确定了吗啡（1.25和5毫克/千克；腹腔注射）的奖赏作用。虽然高新奇寻求者和低新奇寻求者对奎宁厌恶味道的反应没有差异，但对新奇的偏好与更高的口服吗啡量以及5毫克/千克剂量的吗啡诱导的条件性位置偏好增加有关。目前的结果支持了新奇偏好易导致药物滥用的假说。
