A new study conducted by researchers from the University of California, Irvine has revealed that they have discovered a way to reverse the aging process of brain cells, whereby they lose the fibers that receive neural impulses and lead to cognitive decline. Although more research needs to be conducted in order to confirm the findings, they nevertheless shed light on the mechanisms behind cognitive decline and potential strategies to combat them.
"There's a tendency to think that aging is an inexorable process, that it's something in the genes and there's nothing you can do about it," Gary Lynch, co-author of the study, said in a press release. "This paper is saying that may not be true."
The team studied dendrites, the branch-like fibers that are attached to neurons in order to receive signals from other neurons, in rats, due to previous research that points to a reduction in these structures with the aging process.
Using 10-month-old housed "middle-aged" male rats living in enriched environments, the team administered an oral dose of ampakine to 11 rats daily for three months, while the other 12 rats received a neutral placebo. During this time period, the team conducted behavioral tests on the two groups and examined their activity as they explored an unfamiliar environment.
After three months, the team examined the hippocampus, a region of the brain involved in learning and memory, of the rats in the study and compared them to the hippocampi of adolescent rats who were two and a half months old.
The results showed that the middle-aged rats given the placebo had shorter dendrites and a reduction in their branches than the younger rats, whereas the ampakine group possessed dendritic characteristics that were almost indistinguishable from the younger rats. Furthermore, rats treated with ampakine had an increased amount of dendritic spines then both of the other groups.
The team also found that the anatomical differences in the ampakine group showed enhanced brain signaling between neurons, a process called long-term potentiation, that is integral for memory consolidation and learning.
A final interesting finding is that the ampakine rats only spent two days exploring the novel arenas before settling on a predictable pattern compared to the other groups, suggesting that they had better memory of the arena and thus required less time to settle into a pattern.
"The treated rats had better memory of the arena and developed strategies to explore," Lynch said.
"The importance of optimizing cognitive function across the lifespan cannot be overstated," said Carol Barnes, a neuroscientist who was not involved with the study, adding that she believes that the study "is particularly interesting because the drug effect was selective in the brain functions and behaviors that were changed. This is the kind of specificity that could make translation to the clinic possible."
The findings are set to be published in the Feb. 3 issue of The Journal of Neuroscience.
