At EpiGenie, we’ve been struggling to find the time and motivation for exercise since we misplaced those Tae Bo tapes. Sure the treadmill would work, but then we’d have to move all the clothes hanging on it.
However, some recent work from researchers at the University of Bristol in the UK, caught our attention. The team took a close look at how well exercised lab rats performed better in stressful environments than their lazier counterparts. They then went on to show that epigenetic mechanisms in the brain are playing a role. Finally we have less-selfish reasons for surfing on our lunch break!
The scientists used two groups of rats for their study. The first group cranked on an exercise wheel for 4-weeks (experimental group), while the others were more couch potato-like (control group). The team then subjected the two groups to two types of stressful environment: Novel Environment Exposure and Forced Swimming. After the tests were conducted, dentate gyrus (part of the brain associated with neuronal generation, memory formation and freaking out from being overworked) tissue was examined for histone H3 phospho-acetylation and c-Fos induction.
During the Novel Environment Exposure test, the unexercised group was more high strung, exploring their surroundings the whole testing period, where as the group that cranked out reps on the exercise wheel chilled after 15 minutes of exploring and took a nap.
In the Forced Swimming experiment, the rats were placed in a container of water for 15 minutes and observed. This was repeated again 24 hours later for 5 minutes. Both exercised and control groups showed similar behavior in the initial test, but later in the repeat, the exercised rats showed way better mobility, i.e. treading water, behavior compared to control rats who showed much more struggling and swimming behaviors. It was concluded from this result that the exercised group was better able to cope and create memories of the first stressful event, enabling them to react better when exposed the second time.
Unlike most biathalon finales, the brains of these rats were harvested and examined by immunohistochemistry and the research team found significant increases in histone H3 phospho-acetylation and induction of c-Fos in the brains of the exercised rats. When coupled with the behavioral observations, they show how exercise can cause epigenetic changes that lead to enhanced stress response and memory formation.
Catch up on the highlights at PLoS One, Jan 2009