NEUROFILAMENT PHOSPHORYLATION IS INCREASED IN VENTRAL HORN NEURONS OFNEONATAL RAT SPINAL-CORD EXPOSED TO CEREBROSPINAL-FLUID FROM PATIENTSWITH AMYOTROPHIC-LATERAL-SCLEROSIS

Aberrant neurofilament (NF) phosphorylation in the soma of the ventral horn neurons of neonatal rat spinal cord is observed following exposu re to cerebrospinal fluid (CSF) of patients suffering from Amyotrophic Lateral Sclerosis (ALS). CSF samples from ALS and non-ALS neurologica l patients were injected into the spinal subarachnoid space of 3 day o ld rat pups. After 48 h, sections of spinal cords were stained for the presence of phosphorylated NF epitopes with SMI-31 antibody. The numb er of neuronal soma staining with this antibody in the ventral and dor sal horns sides of the spinal cord was counted. There was a significan t 3-fold increase in the number of soma stained with SMI-31 antibody i n the ventral horns of rat spinal cords exposed to CSF of patients wit h ALS compared to cords from rats exposed to CSF of non-ALS patients a nd those which were not exposed to any CSF samples. Such an increase i n staining of neuronal soma was not observed in the dorsal horns. Hype rphosphorylation of neuronal soma suggests an initial stage of degener ative changes occurring in the motor (ventral horn) neurons following exposure to circulating factor(s) in the CSF of patients with ALS. (C) 1995 Academic Press Limited.