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Ghovanloo MR, Effraim PR, Tyagi S, Zhao P, Dib-Hajj SD, Waxman SG. Functionally-selective inhibition of threshold sodium currents and excitability in dorsal root ganglion neurons by cannabinol. Commun Biol 2024; 7:120. [PMID: 38263462 PMCID: PMC10805714 DOI: 10.1038/s42003-024-05781-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 01/04/2024] [Indexed: 01/25/2024] Open
Abstract
Cannabinol (CBN), an incompletely understood metabolite for ∆9-tetrahydrocannabinol, has been suggested as an analgesic. CBN interacts with endocannabinoid (CB) receptors, but is also reported to interact with non-CB targets, including various ion channels. We assessed CBN effects on voltage-dependent sodium (Nav) channels expressed heterologously and in native dorsal root ganglion (DRG) neurons. Our results indicate that CBN is a functionally-selective, but structurally-non-selective Nav current inhibitor. CBN's main effect is on slow inactivation. CBN slows recovery from slow-inactivated states, and hyperpolarizes steady-state inactivation, as channels enter deeper and slower inactivated states. Multielectrode array recordings indicate that CBN attenuates DRG neuron excitability. Voltage- and current-clamp analysis of freshly isolated DRG neurons via our automated patch-clamp platform confirmed these findings. The inhibitory effects of CBN on Nav currents and on DRG neuron excitability add a new dimension to its actions and suggest that this cannabinoid may be useful for neuropathic pain.
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Affiliation(s)
- Mohammad-Reza Ghovanloo
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Center for Neuroscience & Regeneration Research, Yale University, West Haven, CT, USA
- Neuro-Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
| | - Philip R Effraim
- Center for Neuroscience & Regeneration Research, Yale University, West Haven, CT, USA
- Neuro-Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
- Department of Anesthesiology, Yale University School of Medicine, New Haven, CT, USA
| | - Sidharth Tyagi
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Center for Neuroscience & Regeneration Research, Yale University, West Haven, CT, USA
- Neuro-Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
- Medical Scientist Training Program, Yale University School of Medicine, New Haven, CT, USA
| | - Peng Zhao
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Center for Neuroscience & Regeneration Research, Yale University, West Haven, CT, USA
- Neuro-Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
| | - Sulayman D Dib-Hajj
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Center for Neuroscience & Regeneration Research, Yale University, West Haven, CT, USA
- Neuro-Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
| | - Stephen G Waxman
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA.
- Center for Neuroscience & Regeneration Research, Yale University, West Haven, CT, USA.
- Neuro-Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA.
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