A new study by UF neuroscientists demonstrates an example of the brain’s ability to shift and utilize different neural circuits to perform a task in order to compensate for brain aging.
The rat model study, published recently in the Journal of Neuroscience, was designed to test the hypothesis that cognitive impairments due to the aging of certain brain circuits would result in compensatory use of other brain regions to solve tasks.
In a water-maze beacon discrimination task, middle-aged rats were not as consistent as young rats in discriminating between two identical beacons. The investigators hypothesized that aging of the dentate gyrus, which has a key role in discriminating between objects as stimulus features overlap, is linked to age-related variability in performance on the beacon task.
The researchers found that the older, cognitively impaired rats were more likely to rely on memory for the spatial location of the goal, a strategy that the researchers associated with altered gene expression in CA1, a hippocampal region involved in spatial memory. Thus, the use of different strategies and different neural circuits in older rats could provide an animal model for examining cognitive reserve and neural compensation in aging.
The study was led by Garrett Smith, Ph.D., who is in UF’s M.D./Ph.D. program, and Thomas C. Foster, Ph.D., professor of neuroscience and Evelyn F. McKnight Chair for Research on Cognitive Aging and Memory.