The Autonomous University of Barcelona team injected a gene which causes the production of a protein that is blocked in patients with Alzheimer's into the hippocampus — a region of the brian essential to memory processing — in mice that were in the initial stages of the disease.
"The protein that was reinstated by the gene therapy triggers the signals needed to activate the genes involved in long-term memory consolidation," the university said in a statement.
Gene therapy involves transplanting genes into a patient's cells to correct an otherwise incurable disease caused by a failure of one or another gene.
The finding was published in The Journal of Neuroscience and it follows four years of research.
"The hope is that this study could lead to the development of pharmaceutical drugs that can activate these genes in humans and allow for the recovery of memory," the head of the research team, Carlos Saura, told news agency AFP.
Alzheimer's, caused by toxic proteins that destroy brain cells, is the most common form of dementia.
Worldwide, 35.6 million people suffer from the fatal degenerative disease, which is currently incurable, and there are 7.7 million new cases every year, according to a 2012 report from the World Health Organisation.
In 2010 the total global societal cost of dementia was estimated to be $604 billion, according to Alzheimer's Disease International, a federation of Alzheimer associations around the world.