Ancient people knew of the importance of the pineal gland. Magician, Delores Ashcroft-Nowicki says that to the priests of Heliopolis, the embalmers of ancient Egypt (who were the forerunners of today's pathologists), the Star Chamber of Isis (the Holy of Holies) and the Halls of Anubis and Thoth were not just fanciful terms given to mythical locations but were actually places within the living brain where the priests and priestesses traveled to be taught by the gods.
The following is a description of The Star Chamber of Isis given by a priest of Isis undergoing the Rite of the Meeting of Mind with Mind:
“ The corridor is long and narrow and gleams like the inside of a shell drawn from the depths of the sea. The curtains that guard the entrance are of the softest gossamer, so fine that they seem like mist on a lake at dawn. As I pass through them I come into the presence of the Gods. The walls are of silver and give off a faint silver light that illuminates this holy place. Beneath my feet is the sandy silt of the sacred Nile, and all about me I hear the heartbeat of Isis . Behold, I dwell in the Star Chamber of the Goddess.”
The above sounds remarkably like the physical description of the pineal gland, which lies deep within the head, an important link to our deepest selves.
Tantric techniques attempt to produce enlightenment through sexual ecstasy. Pineal DMT release can mediate sexual ecstasy resulting from the strenuous exertion, intense emotions and pneumocatharthis (intense dynamic breathing). It is known that psychedelic features do emerge during orgasm. The link between conscious waking state and deep Shamanic consciousness is BLISS/RAPTURE, feelings associated with intense sexual pleasure.
(NOTE: The secret sex techniques of the Shamanka (female shaman) still in practice in certain rural areas of Brazil , Mexico and South America all, generally, involve breathing techniques.)
Source: Esoteric Wisdom: The Pineal Gland And Shamanism