Is there any scientific basis for kundalini and the chakras?
Research on kundalini is especially spotty. There is no compelling work to show that the system represents insights into actual human anatomy. But it's important to understand that kundalini and its network of channels and chakras is simply how yogins have chosen to explain their experience and that yogins from many cultures have arrived at similar, though not identical, concepts.
The true physical mechanisms underlying these experiences may be very different from those described. Izaak Benthov has proposed a model to explain kundalini in terms of micro- motion in the brain. In this model experiences are associated with parts of the body, such as the heart, because the part of the brain associated with that part of the body is stimulated by micro-vibrations. His model is treated in "The Kundalini Experience'' by Sannella referenced below.
From a practical perspective the key thing is our subjective experience and that the roadmap of these subjective experiences has been mapped out.