Supplemental Figure 2. Reduced synaptophysin immunostaining in the dentate outer molecular layer after expression of hTauP301L in the lateral perforant pathway. Immunofluorescence staining for the nerve terminal marker synaptophysin in the contralateral (LEFT) or ipsilateral (RIGHT) dentate gyrus 3 wks after intra-entorhinal delivery of the AAV-Tau vector. HF – hippocampal fissure; OML – outer molecular layer; MML – middle molecular layer; IML – inner molecular layer. Note that the intensity of synaptophysin staining is similar between the two hemispheres in the IML and MML, but is markedly reduced in the ipsilateral OML, consistent with degeneration of the lateral perforant pathway neurons and synapses. Note also that the ipsilateral molecular layer shrinks, an established response to lesioning of the perforant pathway.