Fig. 2. Influence of different enzyme treatments on microsphere adhesion to hippocampal slices. Densities on the different hippocampal laminae, stratum oriens (so), stratum pyramidale (sp), stratum radiatum (sr), stratum lacunosum-moleculare + dentate outer molecular layer (slm/oml), inner molecular layer + granule cell layer (iml/g), hilus (h), were determined for 10 hippocampal slices (individual columns). (A) Densities of adherent microspheres on different hippocampal laminae on untreated control slices. Densities of adherent microspheres differed significantly between adjacent laminae (Wilcoxon Rank Sum Test, two tailed: P<0.05). (B) Hippocampal slices were incubated with 200 TRU/ml hyaluronidase before the adhesion assay. Note the massive reduction of microsphere adhesion in the layers oml/slm when compared to control slices. Densities of adherent microspheres still differed significantly between oml/slm and iml (Wilcoxon Rank Sum Test, two tailed: P<0.05). (C) Hippocampal slices were incubated with neuraminidase before the adhesion assay. Densities of adherent microspheres on different hippocampal laminae were similar to those on untreated control slices (compare with A) and differed significantly between adjacent laminae (Wilcoxon Rank Sum Test, two-tailed: P<0.05). (D) Hippocampal slices were incubated with 0.25 U/ml chondroitinase before the adhesion assay. Membrane-coated microspheres adhere with laminar specificity to the layers oml/slm. However, the number of adherent microspheres in the layers oml/slm is slightly reduced when compared to untreated control slices (A) or neuraminidase-treated slices (B). (Wilcoxon Rank Sum Test, two-tailed: P<0.05).