Nearly Closed Loops in Biological Systems as Electromagnetic Receptors
  It is noted here that when a nearly closed loop in a biological system, such as a self-synapsing (autapsing) neuron or mutually synapsing pair, is exposed to an AC magnetic field, the induced electric fields in the insulating gaps can be many orders of magnitude larger than the average values typically discussed in the literature.$^{1,2}$ It is suggested that animal nervous systems might possibly be affected in selected spots by man-made alternating magnetic fields at weaker levels than previously supposed.   Radio and microwave radiation should be considered particularly suspect. 
D. Eichler