Susan Wraya, Ursula Ravens, Alexei Verkhratskyc, David Eisner; 2004
The story of muscle electricity and the mechanisms that couple electrical signalling with contraction response began in 1791 when Luigi Galvani placed a nerve of his famous nerve–muscle preparation on the injured skeletal muscle and observed contractions of the uninjured muscle initiated by excitation of the injured one. Thus, the first ever electrophysiological measuring system, the “physiological galvanometer”, was born. Several decades later, a similar experimental approach allowed the discovery of heart electricity. First in 1842, Matteucci demonstrated heart beat induced contractions in neuro-muscular preparation when the nerve of the latter was placed over frog heart, and in 1856 Kölliker and Muller witnessed the same picture when placing the nerve over human heart. Interestingly, from time to time Kölliker and Muller observed two contractions of the muscle in response to a single heart beat, the second being associated with what we now recognize as a T wave. Further developments in electrocardiology commenced with the invention of instrumental techniques allowing measurement of biopotentials, the first being a capillary electrometer, invented by Gabriel Lippman. This instrument recorded heart electric waves using external electrodes. The instrument was designed as a glass tube filled with mercury and immersed in sulphuric acid. The surface of the mercury moved as the potential difference between the mercury and sulphuric acid changed. This motion was afterwards optically magnified and recorded on photographic paper.(Cell Calcium 35 485–489 )
Xanya Sofra Weiss
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