Bratcher Natalie A, Farmer-Dougan Valeri, Dougan James D, Heidenreich Byron A, Garris Paul A
Illinois State University, Normal 61790-4620, USA.
J Exp Anal Behav. 2005 Nov;84(3):371-99. doi: 10.1901/jeab.2005.82-04.
Dose-dependent changes in sensitivity to reinforcement were found when rats were treated with low, moderate, and high doses of the partial dopamine D1-type receptor agonist SKF38393 and with the nonselective dopamine agonist apomorphine, but did not change when rats were treated with similar doses of the selective dopamine D2-type receptor agonist quinpirole. Estimates of bias did not differ significantly across exposure to SKF38393 or quinpirole, but did change significantly at the high dose of apomorphine. Estimates of goodness of fit (r2) did not change significantly during quinpirole exposure. Poor goodness of fit was obtained for the high doses of SKF38393 and apomorphine. Decrements in absolute rates of responding were observed at the high dose of quinpirole and at the moderate and high doses of SKF38393 and apomorphine. Changes in r2 and absolute responding may be due to increases in stereotyped behavior during SKF38393 and apomorphine exposure that, in contrast to quinpirole, were distant from the response lever. The present data provide evidence that sensitivity to reward is affected more strongly by dopamine D1-like receptors rather than D2-like receptors, consistent with evidence from other studies investigating consummatory dopamine behavior and the tonic/phasic dopamine hypothesis.
当用低、中、高剂量的部分多巴胺 D1 型受体激动剂 SKF38393 和非选择性多巴胺激动剂阿扑吗啡处理大鼠时，发现其对强化的敏感性存在剂量依赖性变化，但当用相似剂量的选择性多巴胺 D2 型受体激动剂喹吡罗处理大鼠时，这种变化并未出现。在接触 SKF38393 或喹吡罗的过程中，偏差估计值没有显著差异，但在高剂量阿扑吗啡处理时显著改变。在喹吡罗暴露期间，拟合优度（r2）估计值没有显著变化。高剂量的 SKF38393 和阿扑吗啡获得的拟合优度较差。在高剂量喹吡罗以及中、高剂量的 SKF38393 和阿扑吗啡处理时，观察到反应的绝对速率下降。r2 和绝对反应的变化可能是由于在 SKF38393 和阿扑吗啡暴露期间刻板行为增加所致，与喹吡罗不同的是，这些行为远离反应杠杆。目前的数据提供了证据，表明对奖励的敏感性受多巴胺 D1 样受体而非 D2 样受体的影响更大，这与其他研究探究 consummatory 多巴胺行为和紧张性/相位性多巴胺假说的证据一致。
