The length of daylight hours impacts opioid receptor levels in brown fat. When daylight hours shorten, the receptor activity levels elevate. A similar phenomenon also takes place in the brain. Both phenomena help people and animals in the adaptation to seasonal changes.
utu.fiSubmitted by universityofturku t3_xxxh1m in science
rad0909 t1_irekd12 wrote
I wonder if this is why everyone is in such a good and sociable mood around the holidays?