Seeing is believing: GFP transgenics illuminate synapse elimination

Synapses are lost during developmental synapse elimination. Until now, it has been impossible to follow elimination in the entirety of any neuron's branches and synapses. Using transgenic mice in which one or two of a muscle's motoneurons express variants of GFP, Keller-Peck et al. show in this issue of Neuron that elimination occurs asynchronously by local competitive interactions at each synaptic site, apparently independent of events elsewhere in the neuron's terminal field.