Elsevier

Behavioural Brain Research

Volume 250, 1 August 2013, Pages 23-27
Behavioural Brain Research

Short communication
Infusion of cannabidiol into infralimbic cortex facilitates fear extinction via CB1 receptors

https://doi.org/10.1016/j.bbr.2013.04.045Get rights and content

Highlights

  • Intra-IL infusion of cannabidiol facilitates extinction of contextual fear.

  • Rimonabant blocks the facilitating effect of intra-IL cannabidiol on fear extinction.

  • Cannabidiol may have a therapeutical potential in fear regulation in humans.

Abstract

Previous studies have implicated cannabinoids in extinction of conditioned fear. We have recently showed that intraventricular infusion of the phytocannabinoid cannabidiol (CBD) facilitates fear extinction, but the brain regions underlying this effect remained unknown. Here we demonstrate that repeated microinjections of CBD into the infralimbic cortex (IL) facilitated fear extinction, as indicated by reduced levels of freezing during extinction test. Systemic administration of the CB1 receptor antagonist rimonabant blocked the effects of intra-IL CBD, suggesting that CBD acts through CB1 receptors to facilitate fear extinction. Our findings suggest a potential therapeutic use of CBD for extinction-based therapies of aversive memories in humans.

Section snippets

Contributions

F.H.M., R.R.S., R.M.B and J.A.K. designed and conducted all experiments. F.H.M and R.R.S. wrote the manuscript. R.N.T. supervised the project. All authors edited and accepted the final version of the manuscript.

Acknowledgments

This research was supported by CAPES, PRONEX, FAPESC and CNPq from which F.H.M., R.R.S, R.M.B. and J.A.K. received doctoral fellowship and R.N.T. a research fellowship. The authors would like to thank Dr. Antonio de Padua Carobrez for help with the experimental design and Jose Rodriguez-Romaguera for critical reading of the manuscript and helpful suggestions.

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    These authors contributed equally to this work.

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