Early Bird or Night Owl?

Researchers from the School of Medicine, Swansea University took samples from visitors to the Cheltenham Science Festival yesterday (Thursday 5 June 2008) to identify their natural sleep-wake pattern.

“The novel technique we have developed at Swansea is entirely non-invasive, so we can use it at a public event”, explains Sarah Forbes-Robertson, Research Fellow at the School of Medicine, Swansea University. “Previously you needed to take blood samples to obtain the RNA (ribonucleic acid) needed for this type of research. Our technique allows us to get a useable sample just by swabbing the inside of an individual’s cheek.”

A number of different genes control an individual’s ‘natural’ pattern of wake and sleep – otherwise known as their circadian rhythm. The levels of RNA produced by these different genes indicate how active they are at different times of day. One gene known as Per2 produces the highest levels of RNA at around 4am, and is the gene that is associated with sleeping. The gene examined at the Cheltenham Science Festival event, known as REV-ERB, works in opposition to Per2 having its peak activity at around 4pm, and is thought by researchers at Swansea to be the gene associated with wakefulness. Samples were taken at the start (4pm) and end (5pm) of the event at the Cheltenham Science Festival, and are being analysed by the Swansea researchers. Results will be made available to individuals online.

“To get a full and accurate picture of someone’s natural circadian rhythm you would need to take samples four hourly over a full day and night, and also look at all the genes involved,” explains Sarah. “But by taking samples at 4pm and 5pm to assess the activity of the REV-ERB gene, we will be able to see if patterns of peak gene expression are shifted forwards or back in time from the norm of 4pm. If your peak is earlier than 4pm it would indicate that you are a natural early bird, if you peak later than 5pm then you are more of a night owl.”

The novel technique for measuring gene expression is currently only being used by Professor Johannes Thome’s research team in the Department of Neuroscience and Molecular Psychiatry at Swansea, but is opening up this field of research as individuals can take part in research whilst continuing with their normal day and night activities. The technique is the first that allows researchers to look at RNA using these mouth swabs, rather than DNA.

One key finding from this work is that humans differ significantly to mice. “It has always been assumed that human genes would work in the same way as those for mice where two genes Per2 and Bmal1 work in opposition, Per2 peaking for sleep and Bmal1 peaking for wakefulness. However, in humans these genes appear to work together with both peaking around the same time,” explains Sarah.

The researchers are now looking at various conditions such as Attention Deficit Hyperactivity Disorder to see if this may be linked to disturbed circadian rhythms. Further work is being carried out to identify if the activity of these genes can be permanently altered through unnatural sleep patterns – in shift work, for example. The technique will also allow researchers to assess whether jet lag cures, such as melatonin tablets, actually do anything to alter gene expression.

“Gene expression can be altered by external factors, such as jet lag”, says Sarah. “One interesting finding is that food affects gene expression, so after lunch Per2 has a small peak, leading to that post lunch slump.”

The non-invasive technique for measuring gene expression may also have applications in other areas of research. “It has been suggested that chemotherapy for cancer patients may be far more effective if administered at certain times of the day. Our techniques might be able to confirm this and explain why”, says Sarah.

Curiosity has of course led Sarah to research her own circadian rhythms. “My peak of Per2 – the ‘sleep’ gene – is at 6am rather than at the usual 4am. So I really do have a genetic excuse for not being able to manage early morning meetings!”

Event Details:
Clocking On
Cheltenham Town Hall
Thursday 5 June 2008 4-5pm
£6 (£5)
Tickets: www.cheltenhamfestivals.com
Box Office: 01242 227979