Could you please explain the functioning of the Vajra,Chitra, and the Brahmanadi ?
—John Edwards, Republic of Panama
Swami Kriyananda’s landmark book, The Essence of the Bhagavad Gita, contains an explanation of these subtle spines. (See the index under “vajra”).
Paramhansa Yogananda taught that the sushumna, vajra, and chitra nadis (subtle nerve channels for prana) are three concentrenically placed channels of the astral spine (of the astral body).
The brahmanadi is the spine of the causal body. It is the primal channel through which Brahma (divine consciousness) descends into the human body.
As the yogi’s soul awakens it travels successively through the three astral spines (sushumna, vajra, and chitra) and finally out through the brahma-nadi. These are related, also, to the appearance of the three concentric ringed circular spiritual eye through which our consciousness enters step by step during the same process.
The spiritual eye when seen clearly consists of an outer ring of deep gold, an inner circle of deep blue or indigo, and a five pointed white star in the center. The gold is the astral light, blue the reflection of the causal plane and the Divine consciousness Kutastha Chaitanaya – the “only begotten” son or reflected intelligence of Spirit found IN creation – and the white star is a reflection of the Infinite transcendent spirit beyond all creation.
The spiritual eye is a reflection of the astral (pranic) life force entering through the 6th chakra at the medulla oblongata.
I recommend you obtain a copy of the The Essence of the Bhagavad Gita. It is a treasure for life!