Fig. 1.

Schematic representation of Cx channels: gap junctions (GJs) and hemichannels (HCs). a) Representation of GJ channel communication from cell 1 to cell 2. GJ enable intracellular molecules to diffuse between connected cells. Some of these signaling molecules are ATP, IP₃, Ca²⁺, toxic molecules and antigens (second messengers are represented as green balls) diffuse through cell 1 to cell 2 to coordinate several physiological and pathological functions. b) Representation of HCs on the surface of cells. Upon opening of these channels, intracellular signaling molecules such as ATP, NAD⁺, ions and other small molecules (represented as blue balls) are released into extracellular media.