Feel-Good Brain Chemical's Role in Sleep

A feel-good brain chemical called dopamine has been linked to everything from laziness and creativity to impulsivity and a tendency to partake in one-night stands. Now, we can add sleep regulation to that list. When dopamine latches onto its receptor in a special part of the brain, it seems to signal the body to "wake up" by turning down levels of the sleepiness hormone melatonin, the researchers found. The first clue to this new discovery came when researchers noticed that dopamine receptor 4, a protein on the outside of certain cells that binds to dopamine, was active in the part of the brain called pineal gland. This gland regulates our internal clock, known as our circadian rhythm, by releasing melatonin in response to light. Interestingly, the presence of this dopamine receptor on pineal gland cells seemed to cycle with the time of the day - the receptor numbers were higher at night and lower during the day...read more>>>...