Inhibition of Respiration in Cats by ELF Electric Fields

Cats (Felis domestica) were exposed acutely to electric fields in the frequency range from 0.1 to 50 Hz using contact electrodes. A marked reduction in respiration rate was observed. The maximum sensitivity was of the order of 1 V/m at frequencies of 0.5-2 Hz. Using multiple electrode sites, it was found that the primary locus of action was near the first vertebra. No effects on cardiac frequency were observed at any frequency with fields up to those which caused visible neuromuscular stimulation.