Muscarinic acetylcholine receptor but not nicotinic acetylcholine receptor plays a role in morphine-induced behavioral sensitization in rats

作者：Sun, Jinling; Tian, Lin; Cui, Ruisi; Ruan, Heng; Li, Xinwang^*

来源：Pharmacology Biochemistry and Behavior, 2017, 160: 39-46.

DOI：10.1016/j.pbb.2017.08.005

• mAChR
• nAChR
• Morphine
• Behavioral sensitization
• Rat

Background and Aim @@@ The cholinergic system can affect drug reward. The present study aimed to examine the roles of muscarinic acetylcholine receptor (mAChR) and nicotinic acetylcholine receptor (nAChR) in morphine-induced behavioral sensitization. @@@ Methods: To analyze the roles of mAChR and nAChR in behavioral sensitization induced by morphine (5 mg/kg), seven experiments were designed. Experiments 1 and 2 examined the effects of 3,1, and 0.3 mg/kg scopolamine and 0.2, 0.1, and 0.05 mg/kg scopolamine, respectively, on the locomotor activity when administered alone. Experiments 3 and 4 explored the effect of scopolamine on morphine-induced behavioral sensitization. Experiment 5 studied the effect of mecamylamine on morphine-induced behavioral sensitization. Experiments 6 and 7 investigated the effects of scopolamine + huperzine A and mecamylamine + huperzine A, respectively, on morphine-induced behavioral sensitization. @@@ Results: The results revealed that 3 mg/kg scopolamine, which significantly enhanced locomotor activity when administered alone, inhibited the acquisition of morphine-induced sensitization. However, mecamylamine (0.5, 1, 2 mg/kg) did not have these effects. The co-administration of scopolamine (0.05 mg/kg) + huperzine A (0.4 mg/kg) or mecamylamine (1 mg/kg) + huperzine A (0.4 mg/kg) did not affect the acquisition of morphine induced behavioral sensitization. Scopolamine (0.05 mg/kg) which did not affect the locomotor activity when administered alone, but not mecamylamine (1 mg/kg), reversed the acute attenuation effect of huperzine A (0.4 mg/kg) on morphine-induced locomotor activity at the acquisition stage and reversed the inhibition of huperzine A on the expression of morphine-induced sensitization. @@@ Conclusion: The mAChR might play a more important role in morphine-induced locomotor activity and the expression of morphine-induced behavioral sensitization. The mechanisms of mAChR and nAChR were relatively separate in morphine-induced sensitization.

• 出版日期2017-9
• 单位首都师范大学