immunohistochemistry in human hippocampus. A. The pyramidal cell layer (p) of the CA1 region exhibited moderate to strong staining for γ3. Weak staining was observed in the stratum oriens (o) and stratum radiatum (r). The alveus (a) and lacunosum-moleculare (l–m) are in general, absent of immunoreactivity. B. More intense γ3 immunostaining was observed in the CA2 and CA3 pyramidal cell layers than in CA1. Strong staining was also detected in CA4 cell bodies but surrounding neuropil is devoid of immunoreactivity. C and D. Sections adjacent to those displayed in panels A and B incubated with immunizing peptide-pre-absorbed γ3 Ab. E. Moderate to strong staining of CA1 pyramidal cell bodies and weaker staining in the surrounding neuropil. F. Intense staining of the pyramidal cells of the CA3 with moderate perisomatic staining. G. Cell bodies in the subiculum (Sub) are moderately stained and neuropil staining is very weak. Neuropil staining in panels E, F and G may reflect relative cell densities in each region. H. Granule cells of the dentate gyrus were stained moderately to strongly by the γ3 Ab. The immunoreactivity is mainly in the soma of these cells, but can also be seen in the early branches of the granule cells dendritic trees, which extend into the lightly stained molecular layer. The neuropil of the polymorphic layer is almost devoid of staining. Scale bars in panel A–D represent 250 μm, in panels E–H 25 μm.