Synaptic uSIRPation: The active neuron reigns over presynaptic partners

摘要

What mechanisms control the synaptic wiring of neurons? Although trans-synaptic adhesion complexes can induce and specify synapse formation1 and glia-secreted factors modulate the extent to which neurons can assemble synapses2, the molecular mechanisms through which neuronal activity guides synaptogenesis remain unclear. Conceptually, activity should be a key element in this process, as it could give active neurons a competitive edge over the inactive ones and thereby promote the integration of active neurons into networks. A study by Toth et a} published in this issue of Nature Neuroscience finds that active neurons shed a soluble fragment of the signal regulatory protein (SIRP)-oc to generate a synaptogenic signal, allowing them to govern presynaptic neurons and induce new synapses (Fig. 1).