Retrograde transport of nerve growth factor in chicken embryo

We have demonstrated retrograde transport of nerve growth factor to the dorsal root ganglia in the chicken embryo. Polyacrylamide gel pellets impregnated with 125I-labeled nerve growth factor were implanted subcutaneously in the leg of stage 36 (10-day) chicken embryos. The embryos were killed 8 hr after implantation and were processed for routine autoradiography. Examination revealed significant labeling of all lumbar dorsal root ganglia on the side of the implanted pellet. The lateral motor columns and ventral roots as well as the dorsal roots on both sides were unlabeled. These observations show that in the chicken embryo, during the period of sensory cell sensitivity to nerve growth factor, there is a selective uptake and retrograde transport of nerve growth factor from the target area to the dorsal root ganglia. These observations supplement reports from other laboratories in which selective retrograde transport of nerve growth factor in neonatal and adult rodents has been demonstrated.