کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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6260147 | 1290036 | 2010 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Research reportEffects of physostigmine on the conditioned hyperactivity and locomotor sensitization to morphine in rats Research reportEffects of physostigmine on the conditioned hyperactivity and locomotor sensitization to morphine in rats](/preview/png/6260147.png)
Repetitive exposure to opioids elicits sensitization to its psychomotor stimulating effect and environmental stimuli contribute to this effect. This study first developed a procedure that simultaneously measures conditioned hyperactivity and locomotor sensitization, and then investigated the effects of physostigmine on the development and expression of conditioned hyperactivity and locomotor sensitization in rats. Five groups of rats (10-12 rats each) were conditioned with a conditioned stimulus (CS) for 20Â min and then drug or saline paired with CS for 2Â h daily for 10 days. Rats were tested 20Â min on day 18. On day 25, rats were tested 20Â min and subsequently 2Â h (immediately after morphine injection). Although the 20Â min locomotion was not different among the rats on day 1, rats that received 5Â mg/kg morphine during conditioning showed higher locomotion than those received saline or 5Â mg/kg morphine in the home cage on day 18 and day 25. Rats received 0.1Â mg/kg physostigmine and 5Â mg/kg morphine during conditioning showed higher locomotion than those received 5Â mg/kg morphine on day 18. On day 25, 0.1Â mg/kg physostigmine attenuated the conditioned hyperactivity and expression of morphine locomotor sensitization. In contrast, rats received 0.1Â mg/kg physostigmine and 5Â mg/kg morphine during conditioning showed higher locomotion during 2Â h test period than those received 5Â mg/kg morphine. In conclusion, this study established a procedure that simultaneously study conditioned hyperactivity and locomotor sensitization. Physostigmine attenuates the expressions but enhances the development of conditioned hyperactivity and sensitization and the possible mechanisms are discussed.
Journal: Behavioural Brain Research - Volume 206, Issue 2, 20 January 2010, Pages 223-228