All experience, waking and dreaming, has an energetic basis. This vital energy is called lung* in Tibetan, but is better known in the West by its Sanskrit name, prana.
There are so many different channels in the body.
Channels, prana, and chakras are involved in death as well as life. Most mystical experiences and experiences in the intermediate state after death result from the opening and closing of energy points.
The channels that carry this very subtle energy cannot be located in the physical dimension but we can become aware of them.
There are three root channels. Six major chakras are located on and in them. From the six chakras, three hundred and sixty branch channels spread throughout the body. The three root channels are, in women, the red channel on the right side of the body, the white channel on the left, and the blue central channel. In men, the right channel is white and the left channel is red. The three root channels join about four inches below the navel.
The two side channels, which are the diameter of a pencil, rise up either side and in front of the spine and through the brain, curl under the skull at the top of the head, and open at the nostrils. The central channel rises straight up between them, in front of the spine. It is the diameter of a cane and widens slightly from the heart area to the crown of the head, where it ends.
The white channel (the right in men and the left in women) is the channel through which energies of the negative emotions move. Sometimes the channel is known as the channel of method.
The red channel (the left in men, the right in women) is the conduit for positive or wisdom energies.
Therefore, in dream practice, men sleep on their right side and women on their left in order to put pressure on the white channel and thus close it slightly while opening the red wisdom channel. This contributes to better experiences of dream, involving a more positive emotional experience and greater clarity.
The blue central channel is the channel of non-duality. It is in the central channel that the energy of primordial awareness ( rigpa) moves. Dream practice ultimately brings the consciousness and the prana into the central channel, where it is beyond both negative and positive experience. When this occurs, the practitioner realizes the unity of all apparent dualities. Generally when people have mystical experiences, great experiences of bliss or emptiness or clarity or rigpa, they are energetically based in the central channel.