Puberty turned on by brain during deep sleep

The many changes that occur in boys and girls during puberty are triggered by changes in the brain. Previous studies have shown that the parts of the brain that control puberty first become active during sleep, but the present study shows that it is deep sleep, rather than sleep in general, that is associated with this activity.

"If the parts of the brain that activate the reproductive system depend on deep sleep, then we need to be concerned that inadequate or disturbed sleep in children and young adolescents may interfere with normal pubertal maturation," said Harvard researcher, Natalie Shaw, MD, of Massachusetts General Hospital and Boston Children's Hospital who led the study. "This is particularly true for children who have been diagnosed with sleep disorders, but may also have more widespread implications as recent studies have found that most adolescents get less sleep than they require."

In the study, researchers examined pulses of luteinizing hormone (LH) secretion in relation to specific sleep stages in children ages 9-15. LH is essential for reproduction and triggers ovulation in females and stimulates the production of testosterone in males. Researchers found that the majority of LH pulses that occur after sleep are preceded by deep sleep suggesting that deep sleep is intimately involved in pubertal onset.

Other Harvard researchers participating in the study included James Butler of Brigham & Women's Hospital; and Scott McKinney, Susan Nelson, Jeffery Ellenbogen and senior author Janet Hall, all of Massachusetts General Hospital.