Differential regional expression of α-actinin-2 protein in the hippocampal formation. A, DAB histochemistry showing α-actinin-2 immunostaining pattern in hippocampus. α-Actinin-2 protein is expressed throughout the dendritic fields of all regions, but staining is strongest in the molecular layer of dentate gyrus and in area CA2. The negative image of the photomicrograph is shown to improve contrast. B, Fluorescence immunocytochemistry showing the dashed linepattern of α-actinin-2 immunostaining seen in hippocampus, interspersed among the cell bodies of the pyramidal cell layer in CA1.C, High resolution confocal image of α-actinin-2 immunostaining showing bright puncta on the cell bodies and apical dendrites of CA3 pyramidal cells. Bright puncta are also present on basal dendrites of CA3 pyramidal cells (data not shown).DG, Dentate gyrus; m, molecular layer;p, stratum pyramidale; sl, stratum lucidum; so, stratum oriens; sr, stratum radiatum. Scale bars: A, 500 μm; B, 50 μm; C, 30 μm.