Objectives: Clinical and neurobiological findings suggest that cannabinoids and their receptors are implicated in schizophrenia.
Cannabidiol (CBD), a non-psychotomimetic compound of the Cannabis sativa plant, has been reported to have central therapeutic
actions, such as antipsychotic and anxiolytic effects. We have recently reported that spontaneously hypertensive rats (SHR) present a
deficit in contextual fear conditioning (CFC) that is specifically ameliorated by antipsychotics and aggravated by proschizophrenia manipulations.
These results led us to suggest that the CFC deficit presented by SHR could be used as a model to study emotional processing
impairment in schizophrenia. The aim of this study is to evaluate the effects of CBD and rimonabant (CB1 receptor antagonist) on the
contextual fear conditioning in SHR and Wistar rats (WR). Methods: Rats were submitted to CFC task after treatment with different
doses of CBD (experiment 1) and rimonabant (experiment 2). Results: In experiment 1, SHR showed a decreased freezing response
when compared to WR that was attenuated by 1 mg/kg CBD. Moreover, all CBD-treated WR presented a decreased freezing response
when compared to control rats. In experiment 2, SHR showed a decreased freezing response when compared to WR that was attenuated
by 3 mg/kg rimonabant. Discussion: Our results suggest a potential therapeutical effect of CBD and rimonabant to treat the emotional
processing impairment presented in schizophrenia. In addition, our results reinforce the anxiolytic profile of CBD.
Keywords: Schizophrenia, cannabidiol, rimonabant, contextual fear conditioning, SHR, Cannabis sativa, antipsychotics, proschizophrenia, Wistar rats (WR), freezing response.
Rights & PermissionsPrintExport