Fig. 1
From: Are there gap junctions without connexins or pannexins?
Gap junctions versus syncytium or incomplete cleavage. a Cells connected by GJs are electrically coupled via intercellular channels. Electrical current pulse applied through intracellular microelectrode I2 results in a small ion molecule flow through GJs and leads to membrane potential changes in the adjacent cell recorded by electrode V1. If tracer dye ejected from V1 electrode (green) is bigger than the GJ channel pore size, it is restricted to the cytoplasm of one cell. b Incompletely divided or fused cells show a voltage drop on shared plasma membranes in response to the electrical current pulse applied via I2 (Ric < < Rgj) and at the same time big molecules freely diffuse through the shared cytoplasm