Reactive astrogliosis in neonatal rat spinal cord after exposure to cerebrospinal fluid from patients with amyotrophic lateral sclerosis.

Previous studies have proposed the presence of circulating toxic factor(s) in the cerebrospinal fluid (CSF) of patients with amyotrophic lateral sclerosis (ALS). In the present study we show that there is an increased number of astrocytes intensely immunoreactive for glial fibrillary acidic protein (GFAP) in the gray matter of the spinal cords of neonatal rats exposed to ALS CSF. There is also increased expression of GFAP in the astrocytes of the white matter of neonatal rat spinal cords exposed to ALS CSF. Western blot analysis also confirmed the increased expression of GFAP. Accordingly, our study provides for the first time a clear evidence for the pathological response of glia to the circulating toxic factor(s) in the CSF of ALS patients.