Assertion: melatonin | /r/CreatedBy | gland
Facets:
value: in the brain
type: LOCATION
value: at night
type: TEMPORAL
Source sentences:
text: Melatonin is a natural hormone produced by a gland in the brain at night (when it is dark outdoors).
text: Melatonin is a naturally occurring hormone in the body, produced by a gland in the brain (the pineal gland).
text: Melatonin is a neurotransmitter produced by a gland in the brain that regulates the wake/sleep cycle and other daily biorhythms.