Seasonal Variation In Daylight Influences Brain Function, New Study Confirms

News: We experience more negative emotions in winters than in summer. Seasonal variation in daylight affects the opioids receptors in our brain that regulate both mood and sociability, according to a new study conducted at the University of Turku.

Researchers examined how the length of daylight hours affected the opioid receptors in humans and rats. They changed the length of daylight hours and measured the opioid receptors in rats and humans (204 participants). The team used a small dose of radioactive tracer that binds to the brain’s opioid receptors and is injected into the subjects’ blood circulation. The decay of the tracers was measured with a PET (Positron Emission Tomography) scanner. The team then compared the results obtained from experiments conducted in humans and rats

“On the basis of the results, the duration of daylight is a particularly critical factor in the seasonal variation of opioid receptors. These results help us to understand the brain mechanisms behind seasonal affective disorder,” says Professor Lauri Nummenmaa from the Turku PET Centre.

To Know More You May Refer To:

Sun, L., Tang, J., Liljenbäck, H., Honkaniemi, A., Virta, J., Isojärvi, J., Karjalainen, T., Kantonen, T., Nuutila, P., Hietala, J., Kaasinen, V., Kalliokoski, K., Hirvonen, J., Scheinin, H., Helin, S., Eerola, K., Savontaus, E., Yatkin, E., Rinne, J. O., … Nummenmaa, L. (2020). Seasonal variation in the brain μ-opioid receptor availability. The Journal of Neuroscience, 41(6), 1265-1273. https://doi.org/10.1523/jneurosci.2380-20.2020