This image shows expression of the excitatory postsynaptic marker PSD95 (green) and the presynaptic marker Synapsin-1 (red) in cultured rat cortical neurons that were treated with a soluble Nogo-66 receptor fragment. The ectodomain of NgR1 accelerates excitatory synapse formation. For more information, see the article by Sanz et al. (pages 518–529).