Andrew Huberman· PhD
It's also actively suppressed, at least in some species and we think at least partially in humans, by the tonic release-- that means the ongoing release, around the clock-- of a hormone called melatonin. Later in life-- in fact, after puberty-- melatonin will be secreted only in the dark phase of each night and around the time that one goes to sleep. But in children and in particular in children prior to puberty, melatonin is released more or less constantly.