Brain chemistry alters how we percieve things. All cultures have found ways of reaching 'spirituality' or a connection, or awareness on a higher level. Fasting, peyote, sweat-tents, meditation- all can alter ones perceptions of the world around us. Your 'kundalini' (snigger, sorry, its a funny word- sounds like a ladies furry front-bottom), is very similar to what one experiences on MDMA, or with Ketamin 'high'. I remember one particular evening when me and some friends were smoking some really strong pot whilst listening to an album by 'The Orb'. There was this one frequency on one of the tracks that made all of us have back spasms at the exact same time! It was a real physical reaction to the sound, made possible by the change in our perception due to the drug.
It seems reasonable to me to accept that a meditative state could produce similar changes in brain chemistry to an ingested drug.
Outside of that, I am never going to by the whole chakra/chi/ki/qui/force thing, but then, I am a barbarian who loves the reality of the real.