The production of new nerve cells in the human brain is linked to learning and memory, scientists have found.
The University of Florida researchers provided clues about processes involved in age- and health-related memory loss and reveal potential cellular targets for drug therapy.
The researchers studied how stem cells in a memory-related region of the brain, called the hippocampus, proliferate and change into different types of nerve cells.
"The findings suggest that if we can increase the regeneration of nerve ells in the hippocampus we can alleviate or prevent memory loss in humans," said Florian Siebzehnrubl of the UF College of Medicine.
"This process gives us what pharmacologists call a 'druggable target.'"
In animal studies, it was found that disrupting nerve cell generation resulted in the loss of memory function, while increasing the production of new nerve cells led to improved memory.
To investigate whether the same is true in humans, the UF researchers, in collaboration with colleagues in Germany, studied 23 patients who had epilepsy and varying degrees of associated memory loss.
They analyzed stem cells from brain tissue removed during epilepsy surgery, and evaluated the patients' pre-surgery memory function.
In patients with low memory test scores, stem cells could not generate new nerve cells in laboratory cultures, but in patients with normal memory scores, stem cells were able to proliferate.
That showed, for the first time, a clear correlation between patient's memory and the ability of their stem cells to generate new nerve cells.
"The study gives us insights on how to approach the problem of cognitive aging and age-related memory loss, with the hope of developing therapies that can improve cognitive health in the aging," said J. Lee Dockery of the McKnight Brain Research Foundation.
"Probably everyone will experience some degree of age-related memory loss as a result of the normal aging process," said Dennis A. Steindler of UF's McKnight Brain Institute.
"There is no reason to believe that this is irreversible, and we must find new approaches and therapeutics for allowing everyone to experience productivity and lifelong memory and learning. Facilitating the generation of new functional neurons in our brains throughout life may be one such approach for helping this cause," he added.
The findings were published in the journal Brain.