A new study has revealed that cannabinoids help reverse cognitive decline in older mice, leading scientists to hope for a similar effect in humans.
The study, which was published earlier last month in Nature Medicine, reported that prolonged exposure to low doses of THC appeared to have a lasting impact on the cognition of older mice. Researchers found that THC interacts with receptors in the brain and appears to restore hippocampal gene transcription patterns – in other words, memory and learning capabilities.
Details of the Study
To conduct the study, scientists performed three separate cognitive tests on groups of young, mature and old mice. Both the control group and the test group consisted of mice from all three age groups; the control group was untreated, while the test group was treated to a very small dose of THC for 28 days.
Each group of mice performed three experiments: a water maze, an object location recognition test and a partner recognition test. In each test, the untreated mature and older mice performed significantly worse than the young mice, indicating the common effects of aging on cognitive performance. However, in the group of mice treated with THC, the mature and older mice performed all three experiments with the same capabilities as the young mice.
“Together, these results reveal a profound, long-lasting improvement of cognitive performance resulting from a low dose of THC treatment in mature and old animals. THC treatment for 28 [days] restored the learning and memory performance of mature and old animals in the MWM [Morris water maze test], novel object location recognition and social recognition tests to the levels observed in young mice,” quoted the report.
However, the young mice treated with THC performed worse in every test than their untreated counterparts.”With exposure to THC, “it seems that the young brain becomes old and the old brain becomes young,” explained the study’s coauthor and researcher Andras Bilkei-Gorzo. This confirms previous evaluations that repeated exposure to cannabis at a young age can have lasting negative effects on cognitive development on animals and humans.
Implications for human health
Scientists are optimistic that the results of this study could be the beginning of a new treatment for common human disorders and diseases, such as dementia, multiple sclerosis and Parkinson’s.
“First of all there’s clearly growing interest in the potential therapeutic role of cannabinoids and in this particular case THC on various human conditions,” said Zameel Cader, an associate professor at Oxford University.
However, testing will be difficult moving forward. Scientists must determine both the efficacy and the safety of chronic exposure to THC. There are many questions that need to be addressed first, such as the appropriate time in the human lifespan to begin the treatment. Also, as Cader pointed out, it could be years before side effects manifest and so the evaluation period must be extensive before the treatment opens for popular use.
Although many medical professionals remain skeptical about using cannabis as medical treatments, this study has added to the growing list of positive results. Another recent study released last week demonstrated the effectiveness of THC in treating Dravet syndrome, a rare epilepsy disorder.
With the debate over the health effects of cannabis now in the national spotlight, more research is sure to come.