Experiments have shown that Alzheimer’s disease doesn’t erase memories, but just violates the access to them.
Scientists managed to recover some memories of genetically modified mice with the symptoms of a neurodegenerative disease similar to Alzheimer’s disease. The report of the study was published in the Nature journal.
Through the experiments, the researchers at MIT were able to establish that the plaques of beta- amyloid in the early stages of Alzheimer’s disease do not destroy the memories, but prevent their reading in the hippocampus.
The mice have been genetically modified in order to promote their tendency to form amyloid plaques. In addition, a light-sensitive protein was formed in their neurons, which allowed scientists to selectively activate certain areas of the brain.
In the experiments, the mice which lost memories of the danger to their cell were able to restore them after light stimulation of the hippocampus.
Unfortunately, the researchers note, even after the memory was recovered for a relatively long time, the progressive degeneration of the brain didn’t stop.
Previously, it was also reported about the first case of Alzheimer’s disease infection. British scientists have found that medical procedures can be a source of the infection of Alzheimer’s disease, which until now was considered non-contagious.
Experts said that undersized patients from the UK were infected by Alzheimer’s disease in the course of medical procedures, but it had an extremely long incubation period. These people took a course of treatment of human growth hormone around 50 years ago. In particular, they were administered beta-amyloids (the main component of amyloid plaques founded in the brain of the suffering from Alzheimer’s disease).
In 1958-1985 years, 1848 British with the low growth received injections of growth hormone extracted from the pituitary gland of the dead people. By 1985, this method was put under the ban because of cases of Creutzfeldt-Jakob disease among the patients.
British researchers led by Professor John Collinge conducted an autopsy and analysis of the brain tissue of eight people who died of iatrogenic CJD in the age of 36-58. During the analysis, it was found that in addition to signs of prion disease, beta-amyloid pathology was detected in six patients, as in the four of them – the signs of cerebral amyloid angiopathy (disease also associated with Alzheimer’s disease).
The scientists say that the infection proved untreatable neurodegenerative diseases through injections of growth hormone obtained from corpses. They urge doctors to examine other ways of the prions transfer (via surgical instruments and blood transfusion) to understand whether there is the risk of contracting Alzheimer’s disease or not.