Acetylcholinesterase Activity in Nitella

Abstract

IT is generally accepted that the process of excitation starts with a localized depolarization of the conducting cell membrane. The adjacent region is then depolarized by the resultant current flow. This process repeats itself at successive points and thereby the impulse is propagated. These electrical phenomena have been widely investigated, but the underlying mechanism is still under discussion. Nachmansohn¹ has suggested a theory according to which the acetylcholine system plays an essential part in bioelectrogenesis. Much evidence has been accumulated in favour of this theory during recent years. The evidence is based on experiments with animal cells, mostly nerve and muscle fibres of vertebrates and invertebrates. However, there are plants which resemble nerve and muscle in being able to propagate impulses by electric currents. There is an excitable membrane separating the cell from its environment, in which a sharp decrease in electrical impedance occurs during the passage of an impulse.