immunohistochemistry in human hippocampus. A. In the CA1, alveus (a), stratum oriens (o) most adjacent to the pyramidal layer, and the pyramidal layer (p) all stain moderately for γ2. The stratum radiatum (r) and lacunosum-moleculare (l-m) stain much more weakly. B. Strong detection of γ2 protein occurred in the alveus and pyramidal layers of CA2 and CA3 regions. Moderate immunostaining is detected in stratum lucidum (l). Staining of the strata oriens and radiatum was very weak in this region. The dentate gyrus molecular layer (ML) stains moderately for γ2 and the granule layer strongly (GL). γ2 staining is weak or absent in the polymorphic layer (PL). Cells in the CA4 show moderate staining. C and D. Serial sections to those displayed in panels A and B incubated with synthesis peptide pre-absorbed γ2 Ab. E. In the region of the CA1 towards the CA2 the perisomatic staining is light to moderate with similar staining of the cell bodies. F. In the CA2, staining of neuropil and cell bodies is more intense than in CA1. G. Staining of the soma of the CA3 hippocampal neurons is strong with moderate staining of the surrounding neuropil. H. The dentate gyrus shows moderate staining of the molecular layer and dense immunostaining in the granule layer. The polymorphic layer is weakly stained. Scale bar in panels A–D represents 250 μm, in panels E–H 25 μm. The dotted lines in panels A and B represent the border between the CA4 region of the hippocampus and the polymorphic layer of the dentate gyrus.