Changes in RGC gene expression: QRT-PCR. Changes in gene expression were examined in fluorescence-activated cell-sorted RGCs 4 d after axotomy (Axot) or 4 d after axotomy and simultaneous lens injury (Axot + LI). Results are normalized to expression levels in control RGCs. Representative genes encode growth-associated proteins (gap-43, sprr1a, l1-cam), Nogo receptor (ngr), transcription factors (mafk, c/ebp-β, and c/ebp-d), and the immediate-early gene narp. All ordinate scales are 0-10, except for c/ebp-δ (0-30) and sprr1a, in which the changes are >1000-fold because of almost undetectable levels in control RGCs (asterisk).