Figure 3. Gap junctions in the inner
mature cortical fibers (400-800 μm from the surface) showing several
transitional stages of the structural remodeling of gap junctions. A:
In the more superficial regions, small clusters of crystalline-packed
connexons (arrows) are seen mixed with other loosely-packed connexons
(opened arrows). B: A number of crystalline-packed connexons
(arrows) are often aligned into parallel rows within the otherwise
loosely-packed (opened arrows) gap junction. C: Another example
of a gap junction containing a mixture of crystalline-arranged (arrows)
and loosely-packed (opened arrows) connexons in which the
crystalline-packed configuration is the major form. In the deeper
cortical regions, most connexons are primarily in the tightly- or
crystalline-packed arrangements (arrows) in both large (D) and
small (E) gap junctions. In the images, pf indicates the P face
of membrane and ef indicates the E face of the membrane. The scale bars
indicate 200 nm.