Helps marijuana grow brain cells

Study: cannabis could rejuvenate the brain

The balance between age-typical degradation and the stabilizing processes that start against it determines the exact course of individual aging. There is now increasing evidence that the endocannabinoid system is part of the stabilizing process. This system is so called because its switches also react to substances classically contained in cannabis (THC).

The system switches, the CB receptors (short for cannabinoid), are normally activated by the body's own substances that are similar to THC, the endocannabinoids. This activation modulates the processes that are part of aging and could have a rejuvenating effect on the body, so to speak.

However, the system becomes more inactive with age, as researchers have found in experiments with animals: the brain cells build new CB receptors less often, and these also react increasingly weaker to the endocannabinoids that they are supposed to activate. In addition, there is less of the activating substances in older animals, so the receptor switches not only become rarer and react worse, they are also used less often.

Improved learning performance

Earlier it was shown that mice that were unable to produce a special CB receptor, called CB1, suffered more from the loss of brain cells and earlier deterioration in learning and memory performance in old age. If a decreased activity of CB1 accelerates aging, then couldn't a permanently more active receptor have a positive effect on mental aging? This could be achieved, for example, by increasing the concentration of activating substances such as THC. The age researchers led by Andras Bilkei-Gorzo from the University Hospital Bonn therefore collaborated with Israeli colleagues to investigate whether regular administration of THC can counteract mental aging symptoms.

To do this, the researchers carried out behavioral tests during and after treatment with THC in healthy mice. In the tests, factors such as interest in new things, research behavior (curiosity) and general speed were determined. Where mental aging occurred faster in the earlier study, the opposite effect was now, so to speak, shown: the aged mice improved their learning performance again through treatment with THC. Their mental decline was partially reversed.

This behavioral effect was also accompanied by measurable changes in the brain. Especially in the learning center of the brain, the hippocampus, the treated mice showed more activity and growth of nerve cell connections. The learning cells connected with each other more often, which is understood as a sign of a learning process and memory formation. In the mature mice, the brain activity tapered so much that it resembled the activity in the young mice.

Against mental degradation

So reactivating the slowed down CB1 receptors in the brain could be an effective treatment for mental decline in old age. This appears to be possible at least in mice with a low dose of THC, as occurs in cannabis. In the future, medical cannabis could possibly no longer only be used against pain or loss of appetite in severe illnesses, but also to support healthy mental aging and reactivation of learning and memory performance.

However, one should warn against experimental self-therapy - the Bonn authors give no information on the exact dosage in humans, and there are also unanswered questions about the side effects in mice. (red, November 3rd, 2017)