Protein synthesis at synaptic sites on dendrites

Studies over the past 20 years have revealed that gene expression in neuron s is carried out by a distributed network of translational machinery. One c omponent of this network is localized in dendrites, where polyribosomes and associated membranous elements are positioned beneath synapses and transla te a particular population of dendritic mRNAs. The localization of translat ion machinery and mRNAs at synapses endows individual synapses with the cap ability to independently control synaptic strength through the local synthe sis of proteins. Tbe present review discusses recent studies linking synapt ic plasticity to dendritic protein synthesis and mRNA trafficking and consi ders how these processes are regulated. We summarize recent information abo ut how synaptic signaling is coupled to local translation and to the delive ry of newly transcribed mRNAs to activated synaptic sites and how local tra nslation may play a role in activity-dependent synaptic modification.