Gap junctions in the eye: evidence for heteromeric, heterotypic and mixed-homotypic interactions

Some of the best evidence that different types of gap junction proteins (co nnexins) interact with each other in vivo has been found in the eye. This r eview focuses on three diverse ocular tissues that may contain heterotypic or heteromeric gap junction channels. Each of the tissues uses gap junction s in a superlative fashion: The crystalline lens has an exceptionally high density of gap junctions; the ciliary body expresses a surprising variety o f connexins; the neural retina shows remarkable specificity in the patterns of intercellular coupling. (C) 2000 Elsevier Science B.V. All rights reser ved.