[Electric coupling of frog embryo cells]

Using microelectrode technique the electrical coupling coefficient (Cec) between the blastomeres was shown not to change and to be equal to 1 during the first three divisions of Rana ridibunda embryo. At the same time the duration of cyclic changes in the input resistance (Ri) of the embryo coincided with that of mitotic cycle. The diagram of functional dependence of Cec on the resistance logarithm (Rc) of high permeable cellular contacts (HPC) between blastomeres was plotted. It was shown that changes in the resistance of intercellular gaps (Rg) even within theoretically possible ranges (0----infinity) were unable to produce any changes in Cec, if Rc less than or equal to 10(4) omega, but at the same time may influence the Ri value. The number of ion channels in the contacted membrane was evaluated.