A new study being published in the next issue of the journal eLife, and published online ahead of print by the U.S. National Institute of Health, has found that cannabinoids can enhance visual responses.
“Type 1 cannabinoid receptors (CB1Rs) are widely expressed in the vertebrate retina but the role of endocannabinoids in vision is not fully understood”, the study’s abstract begins. “Here we identified a novel mechanism underlying a CB1R-mediated increase in retinal ganglion cell (RGC) intrinsic excitability acting through AMPK-dependent inhibition of NKCC1 activity.”
According to researchers (and take note that the language used is quite scientific so if you don’t fully understand it, don’t feel bad); “Clomeleon imaging and patch clamp recordings revealed that inhibition of NKCC1 downstream of CB1R activation reduces intracellular Cl– levels in RGCs, hyperpolarizing the resting membrane potential. We confirmed that such hyperpolarization enhances RGC action potential firing in response to subsequent depolarization, consistent with the increased intrinsic excitability of RGCs observed with CB1R activation.”
Using a “dot avoidance assay in freely swimming Xenopus tadpoles”, researchers demonstrated that “CB1R activation [such as done naturally through cannabis consumption] markedly improves visual contrast sensitivity under low light conditions.”
They conclude; “These results highlight a role for endocannabinoids in vision, and present a novel mechanism for cannabinoid modulation of neuronal activity through Cl– regulation.”
The full study – titled “Endocannabinoid signaling enhances visual responses through modulation of intracellular chloride levels in retinal ganglion cells” – can be found by clicking here.