A team of scientists at the Universidad Pompeu Fabra (UPF) in Barcelona have identified the specific part of the brain affected by cannabis and the mechanism by which it causes memory loss, one of the least desirable side-effects of the drug.

'Although the amnesiac effect of marijuana is well known, the exact molecular mechanisms involved had not been isolated until now', explained Andres Ozaita, professor of pharmacology at UPF and one of the directors of the investigative team.

The study, carried out using genetically modified mice, shows that the amnesiac effects caused by marijuana affect the intracellular signalling route known as mTOR, which acts on the brain's hippocampus, the area that controls cognitive response.

'We have discovered the mechanism by which cannabis, which has amnesiac effects, also activates intracelular signals involved in the production of new proteins,' the scientist explained, whilst adding that if these signals could be blocked when cannabis was administered, 'the effects on memory would also be avoided.'

The team hopes that its study, published today in Nature Neuroscience magazine, will lead to ways of preventing memory loss when cannabis is used to treat illnesses like cancer, AIDS, chronic migraine and glaucoma.