Table 2.

Axon number changes (%) in L4 and L5 ventral roots

Stage	PMW	RD	20 d	33 d	50 d	Para
Total axons	−6.2	−9.8	−19.3	−24.1	−30.6	−61.9
Large axons	−19.5	−23.9	−47.1	−45.7	−52.5	−86.0
Large → small	10.9	10.3	20.2	12.1	9.9	2.8
Degenerated large axons	−8.6	−13.6	−26.9	−33.6	−42.6	−83.3

The percent reduction in total axon number and large axon number is calculated in reference to wild-type mice. The definition of large and small axons is described in the text (also see Fig. 5). The fraction of large axons that become small (large → small) is estimated by subtracting the small axon number in the wild-type mice from that of the G93A mice at different stages. The difference between the total lost large axons and the fraction of the large axons that become small (large → small) is the fraction of large axons that are degenerated.