(a) Paired traces depicting the onset of action potentials following current injection (black) and magnetic stimulation (red) for the same neuron co-transduced with AAVs carrying CaMKIIα::Cre-EGFP and CMV::DIO-Magneto2.0. Overlay shows a modest delay of action potential onset (50-100 ms) when neurons are stimulated with static magnetic fields. (b) Magnified traces of the resting state from three additional neurons co-transduced with the above viruses. Neurons are shown immediately prior to action potential initiation as static magnetic fields are brought more closely to the cells using a micromanipulator, a process requiring roughly 1 second. Traces do not show interference coming from ∼50 mT static magnetic fields in close proximity to the recording apparatus.