Fig. 4. Effect of hyaluronidase treatment on the lamina-specific growth of entorhinal fibers in entorhino-hippocampal cocultures. (A) Control: Entorhino-hippocampal coculture after 7 days in vitro (DIV) without addition of enzyme. The entorhinal fibers are visualized by tracing with biocytin. Entorhino-hippocampal fibers (arrow) are restricted to the stratum lacunosum moleculare (slm) and dentate outer molecular layer (oml). Note that entorhinal fibers do not invade the inner molecular layer (iml). The tissue section is counterstained with Cresyl Violet. DG, dentate gyrus; g, granule cell layer; EC, entorhinal cortex; hippocampal areas CA1 and CA3 are indicated. Bar: 100 µm. (B) Hyaluronidase-treated entorhino-hippocampal coculture after 7 DIV. As in control cultures, entorhino-hippocampal fibers project to the slm and the molecular layer (arrow). However, entorhinal fibers are not restricted to the oml but also invade the iml. Bar, 100 µm.
