By Victor M Fontane
The pineal gland was commonly called the “third eye” for many reasons, including its location deep in the center of the brain and its connection to light via the circadian rhythm and melatonin secretion. Many spiritual traditions believe it serves as a connection between the physical and spiritual worlds.
According to this belief, humans had in far ancient times an actual third eye in the back of the head with a physical and spiritual function. Over time, as humans evolved, this eye atrophied and sunk into what today is known as the pineal gland.
Many yoga classes end with bringing sealed palms to the forehead center as the room bows to say “namaste.” Although this can be almost automatic for yoga teachers and students, the significance of this gesture is often not discussed within the context of all-levels classes. The “third eye” is our metaphorical, mystical, and esoteric center of connection to the perception that is often represented as an eye in the center of the forehead. This invisible eye is symbolic of higher consciousness in many cultural and religious traditions, including its significance as the seat of Anja chakra in the Hindu tradition of subtle body energy. Physiologically, the “third eye” is related to the pineal gland, a small, pinecone-shaped endocrine organ in the brain that is situated in the center of the brain. Similar to the “third eye,” the pineal gland has a history of being revered for its supposed spiritual abilities. For example, the French philosopher and scientist René Descartes describes the pineal gland as the meeting place of the physical and spiritual worlds, or “the seat of the soul.” Nonetheless, scientists, philosophers, and theologists continue to dispute the extent of the gland’s abilities.
Curiously, some species of lizards and frogs do have a third eye located at the top of their skulls. Scientists have shown that lizards’ third eye behaves differently from their lateral eyes. Although the cells in their third eye are sensitive to light, the molecules and mechanisms of sending light-sensing signals to the brain differ from those in their lateral eyes. This third eye is thought to be a vestigial organ in humans, meaning that this organ may have been common for primitive vertebrates, but it has lost most of its original function through evolution. The theory has it that the pineal gland evolved from the primitive vertebral third eye to use light to regulate sleep and wake cycles, also known as circadian rhythm (3). Encasing this valuable gland within the structure of our brain and skull may have provided us with an evolutionary advantage by protecting the pineal gland from toxins in the environment.
Several relationships exist between the pineal gland and the retina, which is the part of our eyes that is sensitive to light (4). At a microscopic level, the pineal gland’s cells closely resemble retinal cells. Moreover, the pineal gland and the retina are suspected to be the only two places in the body where direct sensing of light may occur. In response to light, both retinal cells and pineal gland cells synthesize melatonin, the primary hormone associated with circadian rhythm. Melatonin is derived from serotonin, a neurotransmitter that contributes to feelings of happiness and well-being. Melatonin’s relationship to serotonin may be among the reasons that absence of light in the winter months is linked to seasonal affective depressive disorder (SAD), a form of depression that results from low levels of melatonin. This relationship makes the pineal gland a principal organ for psychological well-being.
In addition to its role in circadian rhythm and SAD, there is speculation of the pineal gland’s function in producing “visions.” Scientists have shown that the pineal gland of rats secretes the naturally occurring psychedelic hormone dimethyltryptamine (DMT). This hormone is theorized to contribute to the visual effects or out of body experiences felt during dreaming, birth, near-death experiences, religious experiences, meditation, or other altered states of consciousness.
Comments