Defining gap junctions

This is the authors' abstract. We don't add key points for this paper.

novsky and Revel did not see the hexagonal arrangement as a generalized structure covering large areas of unspecialized membrane."We realized by looking that this was extremely localized," says Karnovsky.It was localized to adhesions.With improvements in electron microscopy came the ability to differentiate between various types of adhesions (see "Defining junctional complexes" JCB.168:989).Revel and Karnovsky (1967) were able to see that their objects of interest were "cell junctions in which there is a minute gap between the external leaflets."Despite repeated use of the word "gap" in the paper, this was the closest they came to actually calling the structures "gap junctions.""We never used this term in the original paper," says Karnovsky, although they did introduce the term in an abstract published soon after (Revel et al., 1967).Revel calls it an "oxymoron," but the attribution has stuck to this day.What Karnovsky and Revel did show was that these junctions were in nonneuronal tissues such as liver and heart.And, unlike tight junctions, the junctions did not act as a barrier: they allowed diffusion of staining salts around them.The distinction between gap and tight junctions was emphasized in more detail by Goodenough and Revel (1970 ) .Karnovsky was too busy with other pursuits, both administrative and scientific, and did not study gap junctions further.Daniel Goodenough went on to purify and determine a preliminary structure of gap junctions (Makowski et al., 1977), with the final structure coming from Unger et al. (1999).Norton "Bernie" Gilula contributed to this latter structure paper and to many other detailed structural and chemical studies, including the classic demonstration of cell-to-cell communication of hormone responses via gap junctions (Lawrence et al., 1978).WW