Role of Neurotrophins in the Formation and Maintenance of Synapses

During development, the establishment of precise synaptic connections between neurons and specific target cells is critical for normal function of the nervous system. Several attributes of neurotrophins, particularly their activitydependent expression and secretion, render these secreted proteins excellent extracellular signals that regulate the formation of synapses. Here we review experimental evidence for the potential role of neurotrophins in synapse formation. Members of the neurotrophin family have been shown to regulate the maturation of both excitatory and inhibitory synapses and also have been demonstrated to impact refinement of synaptic connections. Here, we discuss the multitude of signaling cascades that allow neurotrophins to achieve such diverse effects on CNS development and elaborate on the neurotrophin functions in the regulation of synaptogenesis in several important regions of the mammalian brain.