Fig. 7. Hypothetical role of hyaluronan and hyaluronan-associated molecules in the lamina-specific growth of entorhinal fibers to the dentate outer molecular layer. (A) Hyaluronan-associated cues direct a growing entorhinal fiber to the dentate outer molecular layer and prevent the growth cone from entering the inner molecular layer. (B) The boundary which is normally formed by hyaluronan-associated cues is disrupted by hyaluronidase treatment. Hyaluronan-associated cues are no longer able to prevent the entorhinal fiber from entering the inner molecular layer.