[
Neuron,
2002]
A variety of secreted components have been identified as retrograde signals mediating diverse aspects of synaptic development, maintenance, and plasticity; however, little is known about the mechanisms mediating the release of secreted retrograde signals. Doi and Iwasaki (this issue of Neuron) implicate AEX-1, a protein distantly related to the UNC-13/Munc13 family, as an attractive candidate regulator of the retrograde release machinery in muscle.