Fig. 6.

Full-length APP, secreted APP, and C-terminal fragments of APP accumulate in synaptic sites in the dentate gyrus. [³⁵S]Methionine was injected into rat entorhinal cortex, and transport was allowed to proceed for 6 hr. Subsequently, the entorhinal cortex and the hippocampus were dissected. The hippocampus was sectioned, and the dentate gyrus was removed. The entorhinal cortex, the dentate gyrus, and the remainder of the hippocampus (dorsal hippocampus) were homogenized, and the labeled APP was analyzed by immunoprecipitation with antibodies reactive with the C or N terminal of APP. Recovered immune complexes were resolved on Tris-tricine gels, and the dried gels were exposed for 2 months to x-ray film. APP species were identified as described in the legends to Figures 2 and 3.