Glial cells in the guinea pig myenteric plexus are dye coupled

Glial cells in the myenteric plexus of the guinea pig small intestine were stained intracellularly with Lucifer yellow and horseradish peroxidase. The cells were identified by both their electrophysiological characteristics and by their morphology. Injection of Lucifer yellow, which is known to cross gap junctions, resulted in the staining of many (up to about 100) glial cells. The staining pattern was comparable to the immunostaining of glia with an antiserum for S-100 protein. In contrast to Lucifer yellow, horseradish peroxidase (which does not cross these junctions), was confined to the injected cell. It is concluded that enteric glia are coupled, presumably by gap junctions. This finding indicates that in addition to structural and biochemical similarities, enteric glia may share certain physiological characteristics with central nervous system astrocytes.