Rkieh Nabeel, Cloke Jacob M, Gallagher Nicola, Winters Boyer D, Leri Francesco
Department of Psychology, University of Guelph, 50 Stone Road East, N1G-2W1, Guelph, ON, Canada.
Psychopharmacology (Berl). 2014 Jun;231(11):2339-48. doi: 10.1007/s00213-013-3390-4. Epub 2013 Dec 13.
It has been proposed that drugs of abuse reinforce behavior partly, or wholly, because they facilitate learning by enhancing memory consolidation. Cocaine can clearly serve as a reinforcer, but its effect on learning has not been fully characterized.
To explore the effects of different regimens of pre- and post-training cocaine administration on win-stay and object learning.
Cocaine naïve and cocaine pre-exposed (30 mg/kg/day, × 5 days followed by 7 days drug-free) male Sprague-Dawley rats received cocaine (0, 1, 2.5, 7.5, or 20 mg/kg, i.p.) immediately following training on a win-stay task in a radial maze or following the sample phase of an object learning task. Win-stay performance was also assessed in tests of extinction and after a set shift.
Post-training cocaine did not improve accuracy on the win-stay task and produced performance deficits at 20 mg/kg. These deficits were attenuated by prior cocaine exposure. There was indirect evidence of facilitated learning in extinction and set shift tests, but the effective dosage was different (2.5 and 7.5 mg/kg, respectively). Post-training cocaine produced dose-dependent improvements in object learning.
Post-training cocaine administration can facilitate learning, but this effect is highly dependent on the dose and the type of task employed.
有人提出，滥用药物部分或完全通过增强记忆巩固来促进学习，从而强化行为。可卡因显然可作为一种强化物，但其对学习的影响尚未完全明确。
探讨训练前和训练后给予不同剂量可卡因对赢则停留和物体学习的影响。
初次接触可卡因和预先接触过可卡因（30毫克/千克/天，连续5天，随后7天无药）的雄性Sprague-Dawley大鼠，在放射状迷宫中进行赢则停留任务训练后或物体学习任务的样本阶段后，立即腹腔注射可卡因（0、1、2.5、7.5或20毫克/千克）。在消退测试和定势转换后也评估赢则停留表现。
训练后给予可卡因并不能提高赢则停留任务的准确性，且在20毫克/千克时会导致表现缺陷。预先接触可卡因可减轻这些缺陷。在消退测试和定势转换测试中有间接证据表明学习得到促进，但有效剂量不同（分别为2.5和7.5毫克/千克）。训练后给予可卡因可使物体学习产生剂量依赖性改善。
训练后给予可卡因可促进学习，但这种效果高度依赖于剂量和所采用的任务类型。
