HNK-1 marks earliest axonal outgrowth in Xenopus.

In wholemounts of the very early developing nervous system of Xenopus, HNK-1 specifically labeled cell bodies, axons, and growth cones of identifiable CNS neurons during the period of axonal outgrowth. The unique overview provided by these preparations showed that individual growth cones navigate their routes independently rather than by fasciculation and, further, revealed features of the directional and positional choices made by axons of several different but simultaneously developing pathways.