An Attempt to Explain Nervous Transmitter Release as due to Nerve Impulse‐Induced Cation Exchange

An attempt is made to explain the storage and release of transmitters—particularly in the functional pool—at adrenergic and cholinergic nerve terminals as due to a cation exchange between amines bound to a sulphomucopolysaccharide‐protein complex in transmitter‐containing structures and inorganic ions in the neuro‐effector junctional gap. It is proposed that the exchange occurs at the nerve terminal membrane‐vesicle contact area during the period of nerve impulse‐induced depolarization and increased cation permeability (Fig. 2). The theory allows for a total or fractional release of the granule amine stores with or without a concomitant expulsion of the granule matrix. Such phenomena as reuptake, release by miniature end potentials, by amines and by drugs, fatigue etc. might also be explained on an ion exchange basis.