Lanthanum hydroxide labelling of gap junctions in the odontoblast layer

Earlier work has suggested that terminal nerve fibers in the periphery of the dental pulp are linked to one another and to odontoblasts by gap junctions although positive identification of the junctions was lacking. In this study, the lanthanum hydroxide tracer technique has been used to demonstrate that the junctions in this area do have the characteristic features of gap junctions, a wide dark intermediate line in transverse section, stippling in oblique section and a globular arrangement of sub‐units in tangential section. Other studies have shown these junctions to be of low electrical resistance although the functional importance of this characteristic in this situation has not been determined.