Similar to neurons in the peripheral nervous system, immature CNS-derived RGCs become dependent on target-derived neurotrophic support as their axons reach termination sites in the brain. To study the factors that influence this developmental transition we took advantage of the fact that @entity35 RGCs are born, and target innervation occurs, over a protracted period of time. Early-born RGCs have axons in the SC by birth (P0), whereas axons from late-born RGCs do not innervate the SC until P4-P5. Birth dating RGCs using @entity10081 allowed us to identify RGCs (1) with axons still growing toward targets, (2) transitioning to target @entity734 , and (3) entirely dependent on target-derived support. Using laser-capture microdissection we isolated    34,000 EdU(+) RGCs and analyzed transcript expression by custom qPCR array. Statistical analyses revealed a difference in gene expression profiles in actively growing RGCs compared with target-dependent RGCs, as well as in transitional versus target-dependent RGCs. Prior to innervation RGCs expressed high levels of @entity2136 and @entity20959 a but lower levels of @entity22971 mRNA. Analysis also revealed greater expression of transcripts for signaling molecules such as MAPK, @entity2308 , @entity14889 , and STAT. In a supporting in vitro study, purified birth-dated P1 RGCs were cultured for 24-48 h with or without @entity2136 ; lack of @entity2136 resulted in significant loss of early-born but not late-born RGCs. In summary, we identified several important changes in RGC signaling that may form the basis for the switch from target independence to @entity734 .

The Acquisition of Target Dependence by Developing XXXX Retinal Ganglion Cells(1,2,3).

@entity2136 :: ('24225(Tax:10116)', 'Gene') :: ['BDNF'] @entity2308 :: ('24185(Tax:10116)', 'Gene') :: ['Akt'] @entity10081 :: ('MESH:C032766', 'Chemical') :: ['EdU'] @entity20959 :: ('313173(Tax:10116)', 'Gene') :: ['CNTFR'] @entity22971 :: ('60391(Tax:10116)', 'Gene') :: ['neurexin 1'] @entity35 :: ('10116', 'Species') :: ['rat'] @entity14889 :: ('81646(Tax:10116)', 'Gene') :: ['CREB'] @entity734 :: ('MESH:D019966', 'Disease') :: ['dependence']
@entity35 :: (10116,Species) :: ['Rat']
