Figure 11.

Schematic integrating three aspects of the OSN maturation process based on a compilation of postmitotic data following both the BrdU and 4OH-Tx protocols at P25: (1) cell body radial migration in the OE; (2) differential marker expression; and (3) axon extension from the OE to the OB. Cell morphology changes; expression of GAP 43 (blue), AC3 (maroon), and OMP (gray); and axonal extension progress are correlated with the corresponding postmitotic day. P25-born OSNs extend their apical dendrite and reach the OE surface 2/3 d following mitosis; simultaneously, they extend their axons deep in the basal lamina and express GAP 43; 4 and 5 d after basal cell division, axons cross the cribriform plate and reach the oONL, at which stage cells express AC3; 1/2 d later, axons innervate the oONL and iONL broadly. OSNs express OMP by postmitotic day 8, and, concurrently, their axons reach the GL, ramifying themselves into the glomerular neuropil from day 10 following basal cell division onward. Black dashed line represents the basal lamina. bl, Basal lamina; GL, glomerular layer.