Mossy fiber pathfinding in multilayer organotypic cultures of rat hippocampal slices.

1. Using a novel technique of organotypic cultures, in which two hippocampal slices were cocultured in a bilayer style, we found that the mossy fibers arising from the dentate gyrus grafted onto another dentate tissue grew along the CA3 stratum lucidum of the host hippocampal slice. The same transplantation of a CA1 microslice failed to form a network with the host hippocampus. 2. Thus the type of grafted neurons is important to determine whether they can form an appropriate network after transplantation.