Voltage Dependence of Junctional Conductance in Early Amphibian Embryos

Isolated pairs of blastomeres from early amphibian embryos (Ambystoma, Rana, Xenopus) are electrotonically coupled. Junctional conductance and permeability to the dye Lucifer Yellow are markedly and reversibly decreased by moderate transjunctional polarization in either direction. The relationship between junctional conductance and transjunctional voltage is sufficiently steep that a physiological role in regulation of intercellular communication is plausible.