Table 1.

Ablation of pioneer neurons results in defects in axon pathfinding of the olfactory sensory neurons

	Misrouted	Normal
20 hr ablations
No zns-2 labeling	Posterior 83% (5/6); split 17% (1/6)	0%  (0/6)
Partial zns-2 labeling	Posterior 0% (0/5); split 100% (5/5)	0%  (0/5)
Normal zns-2 labeling	0% (0/6)	100%  (6/6)
38 hr and 46 hr ablations	0% (0/38)	100%  (*38/38)

Thirty-five preparations were analyzed for sensory neuron misrouting by labeling with DiI. Preparations with growth defects and/or poor DiI labeling were excluded from the analysis of both experimental and control groups. 20 hr ablations, A subset of the preparations analyzed with DiI were also analyzed with zns-2 (n=17) and listed here. The misrouting was characterized as “posterior” (Fig. 3B) or “split” (Fig.3C). Numbers indicate the number of preparations showing a given sensory neuron morphology of the total number of preparations with the indicated zns-2 labeling. 38 hr and 46 hr ablations, Ablations done at later times after the first sensory neurons had entered the CNS. *In this group, 5/38 preparations had normal axon projections into the bulb, but within the bulb the terminations appeared disorganized.