A Finnish research group has studied how seasons influence the function of the brain. Researchers at the Turku PET Centre showed that the length of daylight affects the opioid receptors, which in turn regulates the mood we experience.
Seasons have an impact on our emotions and social life. Negative emotions are more subdued in the summer, whereas seasonal affective disorder rates peak during the darker winter months. Opioids regulate both mood and sociability in the brain.
In the study conducted at the Turku PET Centre, Finland, researchers compared how the length of daylight hours affected the opioid receptors in humans and rats.
In the study, we observed that the number of opioid receptors was dependent on the time of the year the brain was imaged. The changes were most prominent in the brain regions that control emotions and sociability. The changes in the opioid receptors caused by the variation in the amount of daylight could be an important factor in seasonal affective disorder.”
Lihua Sun, Postdoctoral Researcher, Turku PET Centre and the University of Turku
Animal studies confirm the significance of daylight
The researchers wanted to ensure that the changes in brain function were caused by the amount of daylight and not some other factor…