Bindu Visarga sits at the summit of Kundalini Tantra as both a subtle physiological center and the metaphysical point where oneness first divides into individual existence.
It is placed beyond the spinal chakras, belonging to the seventh loka of satyam, the plane of truth, and to the causal body or anandamaya kosha.
Chakras as Integrators of the Bodily Systems
In tantric physiology each major chakra gathers and governs the minor centers of a bodily system. The connection in each case is mediated by the particular group of nerves associated with that chakra.
Manipura: the minor centers of the digestive system
Swadhisthana and Mooladhara: the centers of the uro-genital and reproductive systems
Anahata: the minor centers of the respiratory and circulatory systems
Awakening a chakra therefore awakens its nerve plexus and the functions it governs, not only a psychic state.
The Upper Triad: Bindu, Vishuddhi and Lalana
Bindu and vishuddhi are connected via the network of nerves which flow through the interior portion of the nasal orifice, passing through lalana chakra at the uvula or palate.
For this reason awakening is linked. When awakening takes place in vishuddhi, it simultaneously takes place in bindu and lalana.
Tantra goes further and traces the ten paired cranial nerves which emerge along the brain stem to their initial origin within this tiny center. In this view the whole visual, nasal, auditory and tasting systems are ultimately manifestations from bindu.
Location Point: The Shikha
The seat of bindu is at the top back of the head, exactly at the spot where Hindu brahmins leave a tuft of hair growing. In Sanskrit that tuft is called shikha, meaning flame of fire. Here flame stands for the flame of vasanas, the hidden karmas of previous life.
During sandhya, when the child underwent the thread ceremony and was initiated into mantra, the tuft was held, tightened as much as possible and then tied. While practising mantra with the tuft tightened, the child developed a powerful and continuing awareness of this bindu point alone, felt as tightness rather than pain. This is one traditional way to gain contact with Bindu Visarga.
Tantric Physiology
According to tantric tradition, within the higher centers of the upper cortex there is a small depression or pit which contains a minute secretion. In the center of that secretion is a small elevation like an island in the middle of a lake. That tiny point is Bindu Visarga.
Its isolation has never been reported or verified by medical scientists. The texts suggest such a delicate structure would be disrupted during post mortem procedures, and that the tiny amount of fluid could hardly remain localized when more plentiful neural transmitters disperse at death. The parallel often given is the pineal gland, now recognized as the anatomical concomitant of ajna chakra.
Traditional Symbology: Moon and Om
In the tantric scriptures the symbol of bindu is a crescent moon on a moonlit night.
The crescent indicates its relation to the kalas or phases of the moon, as are the endocrine, emotional and mental fluctuations of human beings. Just as the full moon is progressively revealed from new moon to full moon, the immensity of sahasrara is gradually unveiled through ardent practice. The night sky behind it symbolizes the infinity of sahasrara beyond bindu, which cannot be fully experienced while individuality remains.
The symbol of Om also contains bindu in its uppermost part as a small point above a crescent moon. All the chakras are symbolized within the body of Om, along with the three gunas of tamas, rajas and sattva, existing in the realm of prakriti. Bindu is placed separately above to indicate it is transcendental and beyond the fetters of nature. When Bindu Visarga awakens, the cosmic sound of Om is said to be heard as the source of creation.
Seat of Nectar
Many tantric texts describe bindu, the moon, as producing an intoxicating secretion. Yogis are said to be able to live on this ambrosial fluid, making the maintenance of bodily vitality independent of food.
This is linked to reports of human hibernation under strict observation for periods up to forty days. The method described begins with assiduous pranayama until kumbhaka or retention is perfected. Then the hatha yogic form of khechari mudra is performed, in which the frenulum under the tongue is gradually cut and the tongue is elongated over about two years and inserted into the nasopharynx, sealing it like a cork.
By this practice drops from bindu fall to vishuddhi and permeate the whole system. These drops maintain nutrition of the tissues while arresting metabolic processes, so oxygen is no longer required and cellular wastes are not produced. Even facial hair is said not to grow during the period.
Poison Center
Besides nectar, bindu is responsible for poison. The poison glands and nectar glands are situated almost together.
If bindu and vishuddhi are stimulated at the same time there is said to be no danger, because bindu controls the nectar glands and vishuddhi has a bearing on both nectar and poison. As long as nectar is flowing, poison can do no harm. In a body purified through hatha yoga, dhyana and raja yoga, the poison glands are utilized for the production of nectar.
Origin of Individuality
Bindu is considered the origin of creation, the point where oneness first divides to produce multiplicity. The root bind means to split or divide. In some texts it is termed chidghana, that which has its roots in limitless consciousness.
It is a dimensionless center, a gateway to shoonya. This void is not nothingness but no-thingness, pure undifferentiated consciousness. Within bindu coexist infinity and zero, fullness and nothingness, holding the evolutionary potential and blueprint for all objects of the universe.
Here evolution means the vertical, transcendental emergence of life from the substratum, not Darwinian change over time. An individuating principle called kala causes potential in consciousness to accumulate at bindu. From this seed an object, animal or human can manifest. Each has a bindu as its base, lying within hiranyagarbha, the golden womb of creation. That which was formless assumes shape through bindu, and its nature is fixed by bindu.
Bindu is both the means of expression and the means of limitation. Some centers possess consciousness, like man, who has the apparatus to be a conscious center. Most, like stones and elements, are unconscious. Every object evolves into material existence through bindu and is withdrawn back to the source via bindu. It is a trapdoor opening in both directions, and the means through which man can realize the totality of sahasrara.
This creates two human paths:
Pravritti path: the outward path of manifestation. Turning away from bindu toward the outside world, motivated by external events. It leads away from self-knowledge into bondage.
Nivritti path: the reversed spiritual path of wisdom. Turning inward to face bindu and the source of being. It leads back through bindu to sahasrara and to freedom.
The whole purpose of yoga practice is to direct awareness along this evolutionary path.