Cannabinoids are emerging as alternatives to opioids for the treatment of chronic pain. However, much of the evidence supporting cannabinoids as a treatment option is anecdotal and, on the molecular level, we do not fully understand the supraspinal actions of cannabinoids and adaptations that cannabinoids undergo during inflammation. The ventrolateral region of the periaqueductal gray (vlPAG) is an important site for supraspinal actions of cannabinoids. Cannabinoid 1 receptors (CB1Rs) are located on presynaptic terminals within the vlPAG and, when activated, suppress GABA release from the terminal. Inhibition of GABA release in the vlPAG disinhibits vlPAG output neurons resulting in analgesia (or anti-nociception in animal models).
In Aim 1, I will investigate agonist- induced regulation of the CB1R in the vlPAG including desensitization, internalization, as well as a role for protein translation.
Aim 2 will investigate adaptations to CB1R signaling induced by persistent inflammation. I hypothesize that CB1Rs are regulated by protein translation which is dysregulated by persistent inflammation. These features of presynaptic CB1R regulation would distinguish the CB1R from the presynaptic mu- opioid receptor, which does not desensitize. Completion of this proposal will shed light onto mechanisms of the CB1R regulation, the most abundant G-protein coupled receptor in the central nervous system. Further, these experiments will reveal adaptations induced by persistent inflammation that could be important for the development of new therapeutics targeting the cannabinoid system for the treatment of pain. To investigate CB1R regulation and inflammation-induced adaptations, I will learn whole-cell patch clamp electrophysiology, radioligand binding, biotinylation, and puromycin assays under the combined mentorship of Dr. Susan Ingram and Dr. Marina Wolf. Together with the collaborative and top-rated research environment fostered by Oregon Health & Science University and the Neuroscience Graduate Program through the Vollum Institute, Drs. Ingram and Wolf will provide the guidance to empower me to become a successful independent scientist. The Vollum Institute hosts a variety of seminars and student-run lunches which I will attend to learn about ongoing research and meet potential post-doctoral advisors and future collaborators. I will disseminate my research findings through the Vollum Work-in-Progress trainee seminar, presentations at scientific conferences and written publications. Ultimately, the research environment at Oregon Health & Science University and the mentorship of Drs. Ingram and Wolf provides the foundation upon which I can develop into a successful research scientist and become a professor at a research-focused academic institution.
Cannabinoids are emerging as an alternative to opioids for the treatment of chronic pain. Anecdotal accounts indicate that cannabinoids are more effective and less dangerous than opioids, but our knowledge of supraspinal actions of cannabinoids lags behind our understanding of opioid actions. The experiments in this proposal will characterize cannabinoid 1 receptor (CB1R) actions and regulation in the periaqueductal gray, as well as adaptations in cannabinoid signaling in the presence of persistent inflammation.
