Cannabinoid receptors in the basolateral amygdala are involved in the potentiation of morphine rewarding properties in the acquisition, but not expression of conditioned place preference in rats

  • Haghparast A
  • Shamsizadeh A
  • Samandari R
 et al. 
  • 24

    Readers

    Mendeley users who have this article in their library.
  • 8

    Citations

    Citations of this article.

Abstract

Several studies show the role of the basolateral amygdala (BLA) in drug-seeking, relapse and the brains emotional systems. Several lines of evidence indicate a functional interaction between opioid and endogenous cannabinoid systems. In the present study, we investigated the role of intra-BLA cannabinoid CB1 receptors in the potentiation, acquisition and expression of morphine-induced conditioned place preference (CPP). One-hundred and forty-two adult male Wistar rats weighing 230-280 g were bilaterally implanted by two separate cannulae into the BLA. The CPP paradigm was done, and conditioning score and locomotor activity were recorded by Ethovision software. Results showed that intra-BLA administration of different doses of WIN55,212-2 (1, 2 and 4 mmol/0.3 μl DMSO) as a cannabinoid receptor agonist during the conditioning phase induced place preference in animals that received the ineffective (2 mg/kg) dose of morphine compared to respective control group in saline-treated animals. On the other hand, intra-BLA injection of the cannabinoid CB1 receptor antagonist AM251 (45 and 90 μmol/0.3 μl DMSO) during the 3-day conditioning phase reduced morphine-induced CPP. Furthermore, microinjection of both AM251 (15, 45 and 90 μmol) and WIN55,212-2 (1-4 mmol), into the BLA had no effect on the expression of morphine (5 mg/kg)-induced CPP. Our findings suggest that cannabinoid CB1 receptors in the BLA are involved in the development of reward-related behaviors and they can potentiate the rewarding effects of morphine. It seems that the glutamatergic projection from the BLA to the nucleus accumbens and reward-related learning in the hippocampus may be involved in the acquisition and expression of opioid reward-related behaviors in rats. © 2014 Elsevier B.V.

Author-supplied keywords

  • Basolateral amygdala
  • Cannabinoid receptor
  • Conditioned place preference
  • Morphine
  • Rat
  • Reward

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free