The word "pineal" refers to the small gland located in the brain, called the pineal gland. It is responsible for producing a hormone called melatonin, which helps regulate our sleep and wake cycles. Full definition
Sodium fluoride, present in your drinking water and certain store - bought products, and other sources such as Prozac, antibiotics or non-stick cookware could all be contributing to the alarming increase in pineal gland calcification. (fullhealthsecrets.com)
Melanopsin cells in mammals are specialized for measuring ambient illumination, contributing to visual discrimination [8,9], and driving a wide variety of physiological responses including, but not restricted to: synchronization of circadian clocks to light: dark cycles, regulation of pupil size, modulation of sleep and suppression of pineal melatonin production [10 — 14]. (rspb.royalsocietypublishing.org)
In the chick pineal body, activity of the melatonin - forming enzyme hydroxyindole - O - methyl transferase is greater in the light than in darkness. (science.sciencemag.org)