Quantitative studies of ontogenetic changes in the levels of brain-derived
neurotrophic factor (BDNF) mRNA and its effector, BDNF protein, are not ava
ilable for the retinal projection system. We used an electrochemiluminescen
ce immunoassay to measure developmental changes in the tissue concentration
of BDNF within the hamster retina and superior colliculus (SC). In the SC,
we first detected BDNF (about 9 pg/mg tissue) on embryonic day 14 (E14). B
DNF protein concentration in the SC rises about fourfold between (E14) and
postnatal day 4 (P4), remains at a plateau through P15, then declines by ab
out one-third to attain its adult level by P18. By contrast, BDNF protein c
oncentration in the retina remains low (about I pg/mg tissue) through P12,
then increases 4.5-fold to attain its adult level on P18. The developmental
changes in retinal and collicular BDNF protein concentrations are temporal
ly correlated with multiple events in the structural and functional maturat
ion of the hamster retinal projection system. Our data suggest roles for BD
NF in the cellular mechanisms underlying some of these events and are cruci
al to the design of experiments to examine those roles. (C) 2001 John Wiley
& Sons, Inc.