Background: The G protein-coupled receptor 55 (GPR55) is a mammalian orphan
receptor that awaits a formal classification. There are an increasing number of reports directed to
know the physiology and pathophysiology of this receptor. Lamentably, its functions in the central
nervous system (CNS) have been scarcely elucidated.
Methods: A bibliographic search in PubMed database about GPR55 actions in the CNS was made.
The information was grouped for brain structures to facilitate the interpretation. Finally, we
constructed a schematic representation of the current knowledge about the potential participation of
GPR55 in some physiological and pathophysiological events.
Results: Seventy nine papers were included in the review. Only few of them showed data about
GPR55 (mRNA/protein) expression in multiple brain areas. The rest showed findings in different
preparations both in vitro and in vivo conditions that allowed us to speculate a potential activity of
GPR55 in the different brain areas.
Conclusion: GPR55 mRNA is expressed in several brain areas as the hippocampus, hypothalamus,
frontal cortex and cerebellum; but due to the lack of information, only some speculative information
about its function in these regions has been suggested. Therefore, this review provide relevant
information to motivate further research about GPR55 physiology/pathophysiology in the CNS.