Comparison of cocaine reinforcement in lean and obese Zucker rats: Relative potency and reinstatement of extinguished operant responding.
Comparison of cocaine reinforcement in lean and obese Zucker rats: Relative potency and reinstatement of extinguished operant responding.
复制标题
瘦和肥胖 Zucker 大鼠中可卡因强化的比较：相对效力和熄灭的操作反应的恢复。
DOI：
10.1016/j.physbeh.2016.12.016
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发表时间：
2017
影响因子：
2.9
通讯作者：
Freeman,KevinB
中科院分区：
文献类型：
--
作者：
Townsend,EAndrew;Freeman,KevinB
证据表明，肥胖个体在大脑奖励功能上的改变在解剖学和功能上与吸毒成瘾者相似，这在理论上可能使肥胖个体容易滥用药物，而吸毒成瘾者容易暴饮暴食。然而，很少有研究调查这些表型的交叉普遍性。我们最近报道了肥胖的Zucker大鼠中脂肪的强化效果（即值）比瘦的大鼠要大，但发现可卡因的强化效果在两组之间没有差异，这表明精神兴奋剂在瘦和肥胖的Zucker大鼠中是相似的。然而，目前尚不清楚是否其他方面的强化，如可卡因作为强化物的效力或其恢复作用在瘦和肥胖的Zucker大鼠中有所不同。方法本研究比较了自身静脉注射可卡因（0.06 ~ 1.0 mg/kg/注射）的瘦型和肥胖型Zucker大鼠作为强化物的效力，随后测试了提示（光）和药物启动（腹腔注射可卡因；10 mg/kg）对消失的操作反应的恢复。结果所有大鼠均获得可卡因自我给药，并产生倒u型剂量反应函数。在反应消失后，线索和药物启动增加了两组的杠杆按压（即恢复）。在强化效力或恢复作用的可卡因未观察到显着差异作为肥胖的功能。这些结果与我们之前的观察结果相结合，表明可卡因在瘦和肥胖的Zucker大鼠中的强化作用是相似的，并且不支持肥胖与精神兴奋剂的强化作用改变有关的假设。
AimsEvidence indicates that obese individuals exhibit alterations in brain-reward function that are anatomically and functionally similar to what has been observed in drug addicts, which could theoretically make obese individuals vulnerable to drug abuse and drug abusers vulnerable to overeating. However, few studies have investigated the cross-generality of these phenotypes. We recently reported that the reinforcing effectiveness (i.e., value) of a fat was greater in obese Zucker rats than in their lean counterparts, but found no differences in the reinforcing effectiveness of cocaine between groups, suggesting psychostimulant reinforcement is similar in lean and obese Zucker rats. However, it is unknown if other aspects of reinforcement such as cocaine's potency as a reinforcer or its reinstating effects differ in lean and obese Zucker rats.MethodsThe current study compared cocaine's potency as a reinforcer in lean and obese Zucker rats self-administering intravenous cocaine (0.06–1.0 mg/kg/inj), and subsequently tested these subjects in cue- (light) and drug-primed (intraperitoneal cocaine; 10 mg/kg) reinstatement of extinguished operant responding.ResultsAll rats acquired cocaine self-administration and generated “inverted-U” dose-response functions. Following extinction of responding, the cue- and drug-primes increased lever-pressing in both groups (i.e., reinstatement). No significant differences in the reinforcing potency or reinstating effects of cocaine were observed as a function of obesity.ConclusionsThese results, combined with our previous observations, demonstrate that cocaine's reinforcing effects are comparable in lean and obese Zucker rats and do not support the hypothesis that obesity is associated with an altered reinforcing effect of psychostimulants.