Active chemical in cannabis may boost memory and thinking in old mice

08 May 2017

Nature Medicine: A chronic low dose of Δ9-tetrahydrocannabinol (THC) restores cognitive function in old mice

In a new study published today, a team of researchers report that the active chemical found in cannabis, Δ9-tetrahydrocannabinol (THC), can boost memory and thinking in old mice. The study was published on 8 May 2017 in Nature Medicine.

The researchers studied the effects of THC on mice of different ages – young (two months), mature (12 months) and old (18 months). The mice received either a low dose of THC (3mg/kg) or a placebo daily for a period of 28 days, before undergoing tests of their memory and thinking skills. When tested five days after stopping the treatments, the old mice displayed impairments in memory and thinking skills, however these effects were improved in the old mice treated with THC.

The researchers also found that there were age-related changes in the connections between nerve cells, and that these were improved in the mice who had been treated with THC. When they looked at changes in the genes that were being expressed, they found that the THC-treated mature mice had a gene expression profile that was similar to the untreated young mice. The team then investigated the biological processes that could be underlying these observations, finding that the effects of THC may come about through changes in the way genes are regulated.

Dr David Reynolds, Chief Scientific Officer at Alzheimer’s Research UK, said:

“This new study reveals some interesting insights into how THC may boost learning and memory in old mice, but we are still a long way from knowing whether this compound could be used to treat human conditions. As the researchers looked at healthy mice of different ages, it is too early to say whether there are any potential benefits for people living with conditions such as dementia. The majority of studies of cannabis and THC have focused on younger people, finding harmful side effects such as psychosis and problems with memory and thinking. Future studies will need to carefully consider the doses and treatment duration of THC, looking at whether any potential benefits outweigh health risks in older people.”