Do you ever get blamed for being forgetful? Long-term cannabis use has been associated with poor short-term memory. Why is that? Let’s go through some fast facts about the mechanisms.
What are the receptors in the endocannabinoid system? There are three endocannabinoid receptors that have been discovered so far – CB1, CB2, and CB3. The CB1 receptors are located mainly in the central nervous system with a small number in other areas on cells’ surfaces. CB1 receptors are associated with learning, sleep, coordination, and pain sensation. CB2 receptors are different, located throughout the body and associated with immune function. Though only three receptors have been discovered, cannabis researchers believe there may be as many as 10!
When one of the cannabinoid compounds in cannabis called ∆9-tetrahydrocannabinol (THC) binds to and activates the CB1 receptors it was thought that this binding would give cannabis users the memory deficit effect. However, researchers from a recent study found that serotonin 5-HT2A receptors (5-HT2AR) are instead the ones to blame.
Because both CB1 and 5-HT2A receptors are neighbors, when THC binds to CB1R, it signals 5-HT2A by forming a heteromer. To prove this, research experiments were done on mice. When THC binds to CB1R, both the pain-relieving effects and psychoactive effects such as memory loss were observed in normal mice with normal CB1R and 5-HT2AR. However, when blocking the CB1-5-HT2A receptors’ \heteromer, the mice had no psychoactive effects, but no change in pain relieving effects. The same happened to a genetically modified mice which had the 5-HT2AR mice removed; the mice showed no change in pain relieving effects. Similarly, they found that the GM-mice had no signs of memory deficit. This concluded that CB1R was responsible for the anxiety and pain feelings and 5-HT2AR was responsible for the relaxation and memory loss effects.
This is a major find for medical cannabis users to avoid the adverse consequences from using medical cannabis treatments. Now you know there is a way to prevent further memory deficit from using cannabis. However, more studies are needed to put the observation into practice.