The chakras are just the energetic body. Their basis is in the nerve plexuses of the body. The throat, the heart, the solar plexus, the sacral... they all have major endocrine glands and nerve plexuses in those locations, no doubt giving off bioelectric energy. If you can train in seeing auras you can see people's chakras, especially if they're doing any kind of qi gong with their bodies.
Kundalini is real, the sensation is so tangible... makes me wonder if there's a major nervous system component. But who knows.
The chakras are the etheric level of major bio-energy centres of the body, in a nut shell. But I do believe they also contain information pertaining to consciousness, and are not merely some kind of electrical aura. In some of my experiments, I put my hands around a person's chakra while laying on the table, and received insights into what troubles that particular aspect of the energy body. There's way more going on here than modern humans are understanding... makes me wonder about what we have forgotten.