Regular exercise of body and mind can benefit future offspring's brain function, a study in mice has found.
Keeping fit helps individuals keep their own brain health in check, reducing the risk of conditions such as Alzheimer's. Some of these benefits can be passed on to offspring through epigenetics – changes to the DNA's 'packaging', rather than to the DNA sequence itself.
Researchers in Germany have found that if male mice did more exercise, their offsprings' hippocampus – part of the brain involved in learning – had neurons that were better at communicating with each other. Mental exercise was important too, with those living in more stimulating environments also passing on the benefit on offspring. MicroRNA molecules in the sperm were responsible for the effect, the researchers found.
Male mice that passed on more of two specific microRNAs – miRNA212 and miRNA132 – in the sperm had offspring with higher cognitive skills. These microRNAs accounted for some of the inheritance of exercise benefits, but not all.
'For the first time, our work specifically links an epigenetic phenomenon to certain microRNAs,' said Professor André Fischer, author of the study and a researcher at German Center for Neurodegenerative Diseases (DZNE) in Goettingen and the University Medical Center Goettingen (UMG). 'Presumably, they modify brain development in a very subtle manner improving the connection of neurons. This results in a cognitive advantage for the offspring.'
Researchers not involved in the study have welcomed the research. Dr Jon Houseley, principal investigator in epigenetics at The Babraham Institute, called its findings 'intuitive'.
Professor Marcus Pembrey from Great Ormond Street Institute of Child Health in London suggested this type of epigenetic inheritance could work for a variety of traits. 'If this system of the offspring inheriting a 'head start' applies to humans, it might help to explain the so-called Flynn effect where the population IQ in industrial societies has risen every decade for the last century.'
However, further research is necessary to determine whether the benefits of exercise can be passed on in this way in humans. 'It seems unlikely that these particular RNA molecules will also communicate environmental information across generations in humans,' said Dr Houseley. 'However, understanding such inheritance mechanisms in mice suggests ways in which environmental information may be passed to our own children.'
The study is published in the journal Cell Reports.