Article by Josh Kaplan, Ph.D., High Times
With over 30,000 neuroscientists in attendance, the Society for Neuroscience Annual Meeting is the largest source of contemporary brain research in the world. This year’s conference in San Diego, held last month, featured talks and posters from scientists across the research spectrum.
I’ve previously described the hurdles scientists face in legally researching cannabis. One of these hurdles is the need to provide strong justification for possessing the DEA Schedule I license to study cannabis and its derivatives (e.g., cannabidiol). And despite the growing acceptance of medicinal cannabis, its Schedule I classification, by definition, essentially negates its therapeutic potential in the eyes of the funding agencies that largely dictate the direction of research (much of the funding to study the medicinal benefits of cannabis come from private foundations).
Therefore, the majority of research presentations involving THC was focused on public health-related questions, such as how perinatal or adolescent exposure affected brain development and behavior. I’m rarely surprised when studies reveal that artificially manipulating a developing brain with drugs, stress or trauma has harmful consequences. It’s best if kids don’t chug Red Bulls, live in an abusive home or play football. While the harmful effects of THC on the developing brain are now better understood than ever, it remains unclear whether high CBD strains have a protective effect against THC’s effects.
Still, mounting evidence for the benefits of clinical cannabis can’t be ignored.
Scientists with and without Schedule I research licenses are seeking to gain an improved understanding of the brain’s endogenous cannabinoid system to better understand how cannabis or other drugs may work to provide clinical benefits. It’s long been accepted that the CB1 receptor is the primary receptor on brain neurons that mediate the effect of endogenous cannabinoids, such as 2-AG, and exogenous cannabinoids, such as THC.
However, recent evidence has pointed to an important contribution of the CB2 receptor, despite making up less than 1 percent of the brain’s cannabinoid receptors. A research group from the Barrow Neurological Institute in Phoenix investigated the role of CB2 receptors in the brain area involved with learning and memory called the hippocampus. They found that CB2 activation increased the strength of the signaling rhythms within the hippocampus while rats completed a maze. In addition to revealing a significant CB2 role in spatial learning, this finding has important implications for disease states as signaling deficits in the hippocampus are associated with depression and anxiety. Whether CB2 activation in the hippocampus could act as an antidepressant or anxiolytic is an enticing hypothesis that remains to be tested.