Loss of memory in people suffering from neuro-degenerative diseases, including dementia, may be restored with the help of drugs that trigger the natural "rewiring" of brain cells, says a study.
Li-Huei Tsai at MIT in Cambridge, Massachusetts, and colleagues used mice that were genetically modified to produce a protein (p25) when fed an antibiotic. Previous studies have suggested that p25 is linked to brain cell death.
Before triggering p25 production, the mice were placed in a tank of water and trained to find their way to a platform submerged just below the surface. After the mice had developed a long-term memory of the task, the team induced p25 in the rodents, which led to loss of neurons, learning ability and memory.
To see if these faculties could be restored, the mice were placed in an environment enriched with toys and wheels. When the stimulated mice were retested, the researchers found they did better at the memory task than before.
"If memories can be recovered, then that suggests they were never erased and indicates that perceived memory loss is likely to be due to an inability to retrieve memories," Li said.
The mice from the enriched environment turned out to have higher levels of "synaptic marker proteins", an indication that the "wiring" between neurons in the brain had been re-established.
It may be possible to restore lost memories with drugs that trigger the natural "rewiring" of brain cells, the study said.
The findings could lead to new treatments for neuro-degenerative diseases.