Fluorescent dextran-amines used as axonal tracers in the nervous system of the chicken embryo.

We have used recently developed fluorescein- and rhodamine-conjugated dextran-amines as axonal tracers in in vitro preparations of the nervous system of the chicken embryo. These substances are efficiently taken up by injured axons and transported rapidly to the cell bodies. They are also, albeit to a lesser degree, taken up by intact nerve terminals in skeletal muscle. They reveal the dendritic and axonal structure of labelled neurons, and are well suited for use in double-labelling experiments.