Seeing is believing: GFP transgenics illuminate synapse elimination

Synapses are lost during developmental synapse elimination. Until now, it h as been impossible to follow elimination in the entirety of any neuron's br anches 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 issu e of Neuron that elimination occurs asynchronously by local competitive int eractions at each synaptic site, apparently independent of events elsewhere in the neuron's terminal field.