Abstract
Immunofluorescence analysis of basal expression levels of the endogenous GAP-43 protein and the GAP-43-driven transgene gfp in the normal adult mouse brain. Representative high-magnification photomicrographs revealed low levels of endogenous GAP-43 protein immunoreactivity detected in hippocampus dentate gyrus (DG) (A-C) in the pyramidal cells of the CA1—CA3 layers (D, G) and in some cortical neurons (J). Although absent in DG, green fluorescent protein (GFP) immunoreactivity was present in low levels in some pyramidal neurons in the CA1 and CA3 layers (E, H) and in a subset of cortical neurons (K) and colocalized with endogenous protein (F, I, L). In the spinal cord sections, the endogenous GAP-43 and the GFP immunoreactivity are detected in large motoneurons. Double immunofluorescence analysis revealed colocalization with the gfp transgene signal (M—O). Scale bars: (A—C, J—O) 100 μm; (D—I) 50 μm.