Shen Ying-Ling, Chen Yao-Chu, Liao Ruey-Ming
Department of Psychology, National Cheng-Chi University, Taipei 11605, Taiwan.
Behav Pharmacol. 2010 Feb;21(1):77-82. doi: 10.1097/FBP.0b013e3283359f20.
An immediate and robust release of dopamine appears in the brain under an acute stressor, but the functional role of dopamine under stress remains elusive. We recently showed conditioned place preference (CPP) induced by the acute application of a stressor such as being placed on an elevated stand or immobilized in a restraint holder. This study tested whether dopamine is involved in such CPP. The selective dopamine D1 and D2 receptor antagonists, SCH23390 and raclopride, respectively, were injected before stressor manipulation. The doses of SCH23390 (0.025 and 0.05 mg/kg) and raclopride (0.05 and 0.1 mg/kg) used to test for stressor-induced CPP were verified to be ineffective on spontaneous locomotor activity. The results showed that both drugs attenuated the development of stressor-induced CPP. Such a CPP blocking effect by pretreatment of dopamine receptor antagonist was true for either kind of stressor manipulated. These findings indicate that an acute stressor can facilitate a follow-up place conditioning, and that dopamine is involved in the present type of CPP formation.
在急性应激源作用下，大脑中会立即出现大量多巴胺释放，但应激状态下多巴胺的功能作用仍不清楚。我们最近发现，急性施加应激源（如置于高架台上或固定在束缚器中）可诱导条件性位置偏爱（CPP）。本研究测试了多巴胺是否参与此类CPP。分别在应激源操作前注射选择性多巴胺D1和D2受体拮抗剂SCH23390和雷氯必利。用于测试应激源诱导CPP的SCH23390（0.025和0.05 mg/kg）和雷氯必利（0.05和0.1 mg/kg）剂量经证实对自发运动活动无效。结果表明，两种药物均减弱了应激源诱导CPP的形成。多巴胺受体拮抗剂预处理产生的这种CPP阻断效应对于所操作的任何一种应激源都是如此。这些发现表明，急性应激源可促进后续的位置条件反射，且多巴胺参与了当前类型的CPP形成。
