Memory decline in elderly may soon be history

Researchers have claimed to have found a drug therapy that could potentially reverse memory decline in seniors someday.

Researcher Jennifer Bizon, Ph.D., an associate professor in the department of neuroscience and a member of UF's Evelyn F. and William L. McKnight Brain Institute, said that graduate student Cristina Banuelos' work suggests that cells that normally provide the brake on neural activity are in overdrive in the aged prefrontal cortex.

This chemical, an inhibitory brain neurotransmitter called GABA, is essential. Without it, brain cells can become too active, similar to what happens in the brains of people with schizophrenia and epilepsy.

A normal level of GABA helps maintain the optimal levels of cell activation, said collaborator Barry Setlow, Ph.D., an associate professor in UF's departments of psychiatry and neuroscience.

To determine the culprit behind working memory decline, the researchers tested the memory of young and aged rats in a "Skinner box." In the Skinner box, rats had to remember the location of a lever for short periods of up to 30 seconds.

The scientists found that while both young and old rats could remember the location of the lever for brief periods of time, as those time periods lengthened, old rats had more difficulty remembering the location of the lever than young rats.

But not all older rats did poorly on the memory test, just as not all older adults have memory problems. The study shows the older brains of some people or rats with no memory problems might compensate for the overactive inhibitory system - they are able to produce fewer GABA receptors and therefore bind less of the inhibitory chemical.

Older rats with memory problems had more GABA receptors. The drug the researchers tested blocked GABA receptors, mimicking the lower number of those receptors that some older rats had naturally and restoring working memory in aged rats to the level of younger rats.

The findings have been published in the Journal of Neuroscience.