I am not sure what the sky at night presenters said, I don't watch it much since Patrick Moore died. But Pulsars consist of baryons, a strong magnetic field, and the interaction of these lead to radiation (radio, optical, x-ray, gamma-ray). Thats what 99% of astrophysicists believe anyway.

There has been a theory that pulsar emission is due to mutual annihilation of heavy dark matter particles, leading to positrons, electrons and other particles. But I don't think many people believe this.