Paul Saladino· MD
but i think that at least as we believe the majority of the melatonin in the cerebral spinal fluid which is a circadian process comes from the pineal gland you can see here that over a circadian period in the day if you look at the third ventricle and the melatonin in picograms pygrams per ml there's a very circadian pattern whereby in the evening there's a much increased amount of melatonin in the csf of the third ventricle dropping off sharply with the daylight hours