title: Improved instrumentation for measuring the magnetic field of cellular action currents.
mesh_terms: D000200:Action Potentials; D000818:Animals; D004574:Electromagnetic Fields; D055590:Electromagnetic Phenomena / Q000295:instrumentation*; D006801:Humans; D008564:Membrane Potentials; D009412:Nerve Fibers / Q000502:physiology*; D011690:Purkinje Fibers / Q000502:physiology