Topography in Hippocampal Mossy Fiber Plasticity

Neural circuits of vertebrates often display highly ordered projections between different areas, so-called topographic maps, and are characterized by their ability to undergo structural remodeling. In this issue of Neuron, Galimberti et al. demonstrate that mossy fibers of the rodent hippocampus exhibit prominent structural plasticity according to a novel topographic rule, in a process requiring the EphA4 receptor tyrosine kinase.