Altered expression of sialic acid-bearing glycoconjugates as revealed by lectin binding to choroid plexus in perinatal hydrocephalic rats

Glycoconjugates perform key roles in the development and maintenance of the CNS. A chief saccharide element in brain development is sialic acid, usually occurring as Nacetyl-neuraminic acid. Previous studies by H. Jones et al. demonstrated that glyco-conjugate secretions into CSF, by circumventricular organs like the SCO, may be associated with hydrocephalus development. Therefore, we used 4 lectins (LPA, SNA, MAL-II and WGA), specific for several forms of sialic acid, to probe for alterations in sialic acidbearing glycoconjugate profiles in the CSF-secreting choroid plexus (CP) of the HTx rat hydrocephalus model. Lectins are proteins that bind to carbohydrate residues in an antibody-like manner. We used 3 cohorts of rats: prenatal (20 days of gestation); neonatal (1 day after birth); and postnatal (4 days). Five choroid epithelial domains/ parameters were analyzed: apical cell surface; lateral surface; basal surface; cytoplasm; and all domains considered collectively. Staining intensity was judged visually on a 1+ to 4+ scale, at 400×. Means of sialic acid staining intensity were calculated using 5 animals from each cohort.