Abstract
The authors discuss functioning mechanism of a receptor from the viewpoint of engineering. The distinctive features of receptors are :
1) high sensitivity, 2) responsiveness to a wide range of stimulus intensity, in accordance with Weber-Fechner's law, and 3) readiness to respond to a quick change in the intensity of stimulus as compard with a slow change, thus enabling a living system. to be rather sensitive to dynamics of environments than to statics.
Though the functioning mechanism of receptors is generally obscure, a receptor potential, slow change of cell membrane potential evoked by stimulus, may possess a significance in the function of some types of receptors.
The authors simulated the receptor potential generated by a lateral eye of Limulus to a combined model of electrical characteristics of cell membrane and photo-chemical reaction. The model possesses similarities in several aspects which are well known in the physiology of the receptor potential, i. e., 1) time course of the receptor potential, 2) relation between the intensity of stimulus and the receptor potential, 3) effect of concentrations of sodium and potassium ions and that of depolarizing current on the receptor potential, and 4) characteristics of summation, depression, refractoriness and adaptation.
