Fig. 3.
PROT immunoreactivity has a laminar distribution in the adult rat hippocampal formation. A, Low-magnification photomicrograph showing the distribution of PROT immunoreactivity in a coronal section of a mid-rostrocaudal level of the hippocampal formation (level 32 in Swanson). Boxed regions are enlarged in B–D. B, In the CA3 region of the hippocampus a dense array of PROT-immunoreactive processes is found in stratum oriens (so). A few PROT-labeled perikarya (arrows) are observed in stratum pyramidale (sp), whereas negligible PROT immunoreactivity is found in stratum lucidum (slu). C, In the CA1 region of the hippocampus, PROT-immunoreactive processes are densest in strata oriens (so) and radiatum (sr).D, In the dentate gyrus a dense plexus of PROT-immunoreactive processes is found in the inner and outer third of the molecular layer (mo). A few PROT-labeled perikarya (arrows) are detected in the polymorph layer (po). sg, Stratum granulosum;slm, stratum lacunosum moleculare. Scale bar, 100 μm.