Table 1.

Distribution of maximum attained axon collateral lengths

Collateral length (μm)	% of collaterals
≤5	52
6–10	35
11–15	8
16–20	3
>20	2

The behavior of individual filopodia that formed from an axonal shaft was monitored, and the maximal length the filopodium attained during the observation period was measured. A total of 199 axonal filopodia were observed from video records obtained from 14 separate axons from four separate cultures for a total of 2850 μm of axon.