In mammalian brain, glia are likely the most abundant and widespread c
ell population connected by gap junctions. Here, we summarize recent f
indings concerning the distribution, expression, and regulation of gap
junction proteins in different glial subtypes and their possible role
s in modulating the function of the nervous system. Intercellular comm
unication through gap junctions is proposed to be one of the required
interactions between cells during development, and we discuss how gap
junctions could participate in development of brain glial cells.