Neurotrophins as synaptic modulators.

The role of neurotrophins as regulatory factors that mediate the differentiation and survival of neurons has been well described. More recent evidence indicates that neurotrophins may also act as synaptic modulators. Here, I review the evidence that synaptic activity regulates the synthesis, secretion and action of neurotrophins, which can in turn induce immediate changes in synaptic efficacy and morphology. By this account, neurotrophins may participate in activity-dependent synaptic plasticity, linking synaptic activity with long-term functional and structural modification of synaptic connections.