A clue as to why it’s so hard to wake up on a cold winter’s morning

Do you remember the challenge of waking up on winter’s cold, dark days? Neurobiologists have uncovered a clue to what’s behind this behavior. In a study of the fruit fly, the researchers have identified a ‘thermometer’ circuit that relays information about external cold temperature from the fly antenna to the higher brain. They show how, through this circuit, seasonally cold and dark conditions can inhibit neurons within the fly brain that promote activity and wakefulness, particularly in the morning.