Fig. 1.

Generalized models of different connexin coupling patterns in the most common type of gap junctions in the CNS. a “Homotypic” neuronal gap junction, with intercellular channels composed of Cx36 coupling with Cx36. b “Trihomotypic” astrocyte-to-astrocyte gap junction, with intercellular channels composed of Cx43 coupling with Cx43, Cx30 coupling with Cx30 and Cx26 coupling with Cx26. c “Triheterotypic” astrocyte-to-oligodendrocyte gap junction, with astrocyte Cx43 coupling with oligodendrocyte Cx47, astrocyte Cx30 coupling with oligodendrocyte Cx32 and astrocyte Cx26 coupling with oligodendrocyte Cx32. Additional permissive coupling pairs are discussed in the text