Title

 

Authors

P. Campolongo¹, V. Trezza², V. Cuomo¹

1 Dept. of Physiology and Pharmacology, University of Rome “La Sapienza”, P.le A. Moro 5, 00185 Rome, Italy;
2 Dept. of Biology, University RomaTre, V.le Marconi 446, 00146 Rome, Italy

 

Abstract

The activation of neuromodulatory systems affecting the amygdala plays a key role in enabling emotionally significant experiences to be well remembered. Extensive evidence indicates that the basolateral complex of the amygdala (BLA) modulates the consolidation of memories for emotionally arousing experiences, an effect that involves the activation of the glucocorticoid system. The endocannabinoid system plays an important regulatory role in several brain functions, including emotionality and cognition. The BLA expresses high densities of cannabinoid CB1 receptors. Interestingly, there is a bidirectional crosstalk between the endocannabinoid and the glucocorticoid systems. In view of this, we have recently shown that the CB1 receptor agonist WIN55,212-2 (5-50 ng/0.2 µL per side), infused bilaterally into the BLA of male Sprague-Dawley rats immediately after inhibitory avoidance training, enhances memory consolidation; this effect is dependent on activation of CB1 cannabinoid receptors ¹. Furthermore, we have shown that CB1 activity within the BLA mediates glucocorticoid effects on memory consolidation¹. Nowadays, more innovative and selective pharmacological approaches exist to enhance endocannabinoid signalling in the brain. Several lines of evidence identify, indeed, indirect cannabinoid agonists as a novel therapeutic approach for the treatment of central nervous system disorders. We demonstrated that post-training intra-BLA infusions of URB597 (3-30 ng/0.2 µL per side) enhanced 48-h inhibitory avoidance retention performance and that such effect is dependent on anandamide-mediated activation of CB1 cannabinoid receptors. The present findings further support the notion that the activation of the endocannabinoid system in the BLA enhances memory consolidation for emotional experiences.

1.         Campolongo, P. et al. Endocannabinoids in the rat basolateral amygdala enhance memory consolidation and enable glucocorticoid modulation of memory. Proc Natl Acad Sci U S A 106, 4888-93 (2009).