Scientists at the University of Bonn together with colleagues at The Hebrew University of Jerusalem (Israel) carried out a study which proved that more than a two-month-old mice with the help of a cannabis active ingredient were able to regress to the state of two-month-old mice. As the results were presented in the journal Natural Medicine, this breakthrough discovery completely changes the current treatment of dementia.
Dementia is promoted as we grow old: cognitive ability decreases, learning becomes a difficult task and multitasking is out of the question. As a result, researchers were kept busy to find possible solutions to slow down or even reverse the process.
The German and Israeli scientists have successfully tested this method on mice. As mice naturally have a short lifespan, they showed cognitive deficiency even at twelve month of age.
First, they injected a small dose of the active ingredient in the hemp plant, cannabis (THC) to mice aged two, twelve and 18 months over a period of four weeks. Afterwards, they conducted several tests on the mice’s learning capacity and memory performance such as orientation skills and the recognition capabilities.
The mice who were only given a placebo, presented natural age-dependent learning and memory losses while mice who were treated with THC showed cognitive abilities which were just as good as the two-month-old mice.
“The treatment completely reversed the loss of performance in the old animals,” said Prof. Andreas Zimmer from the Institute of Molecular Psychiatry at the University of Bonn and member of the Cluster of Excellence ImmunoSensation.
Years of repeated examinations
The treatment was successful thanks to the carefully conducted research over the years. First, it was discovered that the brain is aging much faster when the mice`s organism does not contain the functional receptors for THC.
A protein called cannabinoid 1 (CB1) functions as a receptor that makes the substances attach and trigger a signal chain which is the reason for the stimulating effect of THC in cannabis products like hashish or marijuana. The (CB1) proteins are accumulated in the receptor while THC imitates the effect of the natural production of cannabinoids in the body thus boosting the brain memory efficiency.
“With increasing age, the quantity of the cannabinoids naturally formed in the brain reduces,” says Prof. Zimmer. “When the activity of the cannabinoid system declines, we find rapid ageing in the brain.”
Old mice were subjects to the THC treatment which the researchers carried out to discover the THC effects on the brain through examining the mice`s brain tissue and gene activity.
The results showed that the molecular signature of old mice has completely changed and now has significant similarities with the molecular signature to that of young mice.
The numerous connections between the nerve cells in the brain were slightly increased, which is very important for induction of the learning ability. “It looked as though the THC treatment turned back the molecular clock,” says Zimmer.
Further plans to examine the treatment on humans
Researchers agreed to inject a small dose of THC in the mice to avoid unwanted consequences. Today, cannabis products are widely used as pain relief medication which raises interests for further examination of THC as a helpful ingredient for the age reversing processes that can highly increase the cognitive ability in the human brain.
The North Rhine-Westphalia science minister Svenja Schulze was surprised by the success of the study: “The promotion of knowledge-led research is indispensable, as it is the breeding ground for all matters relating to application. Although there is a long path from mice to humans, I feel extremely positive about the prospect that THC could be used to treat dementia, for instance.”