12-and 18-month old mice that were given a low dose of THC daily for 4 weeks performed as well as 2-month old control mice on learning and memory tests. The THC treatment completely reversed the loss of performance in the old animals. The mechanism is still unclear. Other studies have found that THC helps clear away amyloid beta plaques from the brain. Additionally, cannabinoids bind to specific receptors called cannabinoid receptors in neurons as well as on immune cells. It is possible that there are multiple mechanisms at play.