Fig. 3. Schematic of gap junctional channels in a biologic membrane. The membrane is schematized as a lipid bilayer, with circles indicating the polar head groups and squiggly lines the fatty acid tails of the lipid. The connexons forming the gap junction have been split down the center to reveal the aqueous pore. (Adapted from Kandel, Schwartz: Principles of Neural Science, 2d ed. Elsevier, 1985)