Is Thinking Bad For Your Brain?
Basic scientific research, old wives’ tales, and common sense all suggest that the best way to promote brain function is to keep your mind active. Intriguingly however, a recent report from Elsa Suberbielle and colleagues published in the journal Nature Neuroscience, seems to suggest just the opposite.
The DNA double helix that encodes the human genome is comprised of approximately 3 billion base pairs that dictate all of our characteristics, ranging from our eye color to our predisposition to heart disease. Disruption of proper base pairing including mutations, insertions, and deletions may lead to a variety of changes in our makeup. Although some of these base pair disruptions are more deleterious that others, double stranded breaks (DSB) in the DNA double helix remains of the most lethal.
Recent evidence indicates that normal exploration of a new environment causes significant increases in DNA DSBs in mice. In these studies, mice were moved from their home cage to a new larger cage comprised of different litter, odors, stations, and toys. They were allowed to explore the new cage for two hours with other mice that they were familiar with from their home cage. Interestingly, many of the documented breaks in DNA were found in the brain region referred to as the dentate gyrus, which is a critical region for learning and memory.
While, at first glance these data seem to suggest that “normal” thinking is bad for us, commentary from Herrup and colleagues addresses this issue. They report that while the data is scientifically sound, they may need to be viewed from a different perspective. For example, they suggest that the assays used to measure DNA DSBs may in fact be leading to the reported damage and that this idea should be further examined. In addition, is possible that the damage in DNA is functioning as a regulatory mechanism. Perhaps, by allowing some level of DNA damage, a higher degree of neuronal regulation can be achieved. Suberbielle hypothesizes that the formation of the DSBs is a natural process that permits for the remodeling of DNA and changes in gene expression that are necessary for learning, memory, and the effective processing of information.
It may be enticing to initially conclude from this report that thinking is bad for your brain. However, these data should be intended as a springboard for further studies in this area and the genetic regulatory mechanisms that are in place during “normal” brain function.
Herrup, K., Chen, J., & Li, J. (2013). Breaking news: thinking may be bad for DNA Nature Neuroscience, 16 (5), 518-519 DOI: 10.1038/nn.3384
Suberbielle, E., Sanchez, P., Kravitz, A., Wang, X., Ho, K., Eilertson, K., Devidze, N., Kreitzer, A., & Mucke, L. (2013). Physiologic brain activity causes DNA double-strand breaks in neurons, with exacerbation by amyloid-? Nature Neuroscience, 16 (5), 613-621 DOI: 10.1038/nn.3356
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