• spinal cord sections revealed many abnormalities in motor neurons of the anterior horn and the dorsal root ganglia, including swelling of perikaraya and proximal axons

• immunofluorescence staining demonstrated that the swelling was the result of heteropolymerization of multiple neurofilament subunits

• distal axons of the sciatic nerve appear shrunken in caliber with thick myelin sheaths

• when lifted by the tail, mice contract their forelimbs and hindlimbs, compared to control mice that extend their legs

• mice are described as displaying fine tremors by 6 months of age

• severely affected mice are unable to support their weight when grasping a pencil

• spinal cord sections revealed many abnormalities in motor neurons of the anterior horn and the dorsal root ganglia, including swelling of perikaraya and proximal axons

• immunofluorescence staining demonstrated that the swelling was the result of heteropolymerization of multiple neurofilament subunits

• distal axons of the sciatic nerve appear shrunken in caliber with thick myelin sheaths

• when lifted by the tail, mice contract their forelimbs and hindlimbs, compared to control mice that extend their legs

• mice are described as displaying fine tremors by 6 months of age

• severely affected mice are unable to support their weight when grasping a pencil