Rezaei Zahra, Alaei Hojjatallah, Reisi Parham
Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
Adv Biomed Res. 2022 Jan 31;11:8. doi: 10.4103/abr.abr_284_21. eCollection 2022.
In the present study, the effects of intra-basolateral amygdala (BLA) blockade of dopamine D1 receptor on morphine-induced conditioned place preference (CPP) were investigated in male Wistar rats.
A 5-day CPP paradigm was used. Morphine was injected subsequently at effective (5 mg/kg) and ineffective (0.5 mg/kg) doses. SCH 23390 (0.5- μg/rat), as a selective D1 receptor antagonist, was microinjected bilaterally into the BLA.
Effective dose of morphine induced a significant CPP, and increased the locomotor activity during the testing phase. The results showed that morphine-induced CPP was significantly suppressed by D1 receptors antagonist in BLA in the acquisition phase and caused an aversion even at high doses. The antagonist also significantly prevented CPP expression. Morphine increased the motor activity, but the D1 receptors blockade, significantly reduced it.
The findings of this study suggest a possible role for BLA dopamine D1 receptors in reward responses in morphine dependency.
在本研究中，研究了在雄性Wistar大鼠中，基底外侧杏仁核（BLA）内多巴胺D1受体阻断对吗啡诱导的条件性位置偏爱（CPP）的影响。
采用为期5天的CPP范式。随后分别以有效剂量（5mg/kg）和无效剂量（0.5mg/kg）注射吗啡。将SCH 23390（0.5μg/大鼠）作为选择性D1受体拮抗剂双侧微量注射到BLA中。
有效剂量的吗啡诱导出显著的CPP，并在测试阶段增加了运动活性。结果表明，在获得阶段，BLA中的D1受体拮抗剂显著抑制了吗啡诱导的CPP，甚至在高剂量时也会引起厌恶。该拮抗剂还显著阻止了CPP的表达。吗啡增加了运动活性，但D1受体阻断显著降低了运动活性。
本研究结果表明，BLA多巴胺D1受体在吗啡依赖的奖赏反应中可能发挥作用。
