AUTHOR=Luongo Livio , Guida Francesca , Maione Sabatino , Jacobson Kenneth A. , Salvemini Daniela TITLE=Adenosine Metabotropic Receptors in Chronic Pain Management JOURNAL=Frontiers in Pharmacology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2021.651038 DOI=10.3389/fphar.2021.651038 ISSN=1663-9812