ABSTRACT
This chapter begins with the essential neuroendocrinological aspects of the pineal that makes it the master gland and then progressing to how it may interface with “spiritual” experiences, which paradoxically bring us back to fundamental principles of pineal physiology. The pineal's most widely known function is its ability to use external light to generate an entrainment of the body to daily and seasonal rhythms of the sleep–wake cycle. The pineal gland undergoes a gradual process of calcification throughout life. A great deal of research has been performed to determine the importance of the role of each of the precursors of melatonin. Normally, melatonin follows a reliable bell-shaped pattern of peaking at night and returning to lower levels by morning. Melatonin is involved in both humoral and cell-mediated immune responses, and pinealectomy or other means of blocking melatonin are correlated with distinct immune depression.
