MICROANATOMY

Detailed explanation-1: -The main function of the pineal gland is to receive information about the state of the light-dark cycle from the environment and convey this information by the production and secretion of the hormone melatonin.

Detailed explanation-2: -Pineal factors influence testicular function by interaction with the neuroendocrine system to affect pituitary gonadotropin secretion. The higher neural centers appear to be responsive to indoles and via the releasing factors give rise to changes in pituitary content and circulating levels of FSH and LH.

Detailed explanation-3: -The pineal gland is best known for the secretion of the hormone melatonin, which is released into the blood and possibly also into the brain fluid, known as cerebrospinal fluid.

Detailed explanation-4: -Melatonin is the only known hormone synthesized by the pineal gland and is released in response to darkness hence the name, “hormone of darkness” [10]. Melatonin provides a circadian and seasonal signal to the organisms in vertebrates.

Detailed explanation-5: -Pursuing with clinical trials, it was shown that testosterone treatment of male patients with GnRH deficiency decreased melatonin to basal levels [55]. In addition, using male pineal cultured glands, it was demonstrated that testosterone significantly increased melatonin release [56].