Size of motor neurons in L4 and L5 ventral roots.1, Photographs of ventral root axons of 1-year-old normal and transgenic animals. 1A, Nontransgenic animal.1B, Line SOD1-4305. 1C, Line G37R-3156.1D, Line G37R-4012. Scale bar, 100 μm.2, Axon counts in L4 and L5 ventral roots of 1-year-old normal and transgenic animals. 1, 2, No significant differences are seen between the normal and transgenic animals.