Dipartimento di Scienze del Farmaco, Università di Sassari, Sassari, Italy.
Pharmacol Biochem Behav. 2010 Aug;96(2):194-7. doi: 10.1016/j.pbb.2010.05.004. Epub 2010 May 9.
The analysis of licking microstructure provides measures, size and number of licking bouts, which might reveal, respectively, reward evaluation and behavioural activation. Based on the ability of the dopamine D2-like receptor antagonist raclopride to reduce bout size and to induce an "extinction mimicry effect" on bout number, we suggested that the level of activation of reward-associated responses is updated, or "reboosted", on the basis of a dopamine D2-like receptor-mediated evaluation process occurring during the consummatory transaction with the reward. Here we investigate the effects of the dopamine D2-like receptor antagonist raclopride (0, 25, 125, and 250microg/kg) on the microstructure of licking for water and sodium chloride solutions (0.075M, 0.15M, and 0.3M) in 12h water-deprived rats. In each session, rats were exposed to brief contact tests (1min) for each solution. Bout size, but not bout number, was decreased at the highest NaCl concentration. Raclopride reduced lick number owing to reduced bout size, while bout number was either not affected or even increased depending on the dose. These results are in agreement with the previous observations on sucrose licking, and suggest the involvement of dopamine D2-like receptors in an evaluation process occurring during the consummatory transaction with the reward.
舔舐微观结构的分析提供了措施、舔舐回合的大小和数量，这些可能分别揭示了奖励评估和行为激活。基于多巴胺 D2 样受体拮抗剂氯丙嗪减少回合大小并对回合数量产生“消退模拟效应”的能力，我们认为与奖励相关反应的激活水平是基于在与奖励的消耗性交易过程中发生的多巴胺 D2 样受体介导的评估过程进行更新或“重新增强”的。在这里，我们研究了多巴胺 D2 样受体拮抗剂氯丙嗪（0、25、125 和 250μg/kg）对 12 小时水剥夺大鼠舔水和氯化钠溶液（0.075M、0.15M 和 0.3M）微观结构的影响。在每次会议中，老鼠都会接触到每种溶液的短暂接触测试（1 分钟）。在最高 NaCl 浓度下，回合大小而非回合数量减少。氯丙嗪降低了舔舐次数，这是由于回合大小减小，而回合次数要么不受影响，要么根据剂量甚至增加。这些结果与先前对蔗糖舔舐的观察结果一致，表明多巴胺 D2 样受体参与了与奖励的消耗性交易过程中的评估过程。
