Presynaptic differentiation and retrograde signalling during the early phase of synaptogenesis

An intricate series of inductive mechanisms orchestrates the development of synaptic specializations at neuromuscular junctions. We focus our attention on the differentiation of the presynaptic nerve terminal induced by retrograde signals from the muscle cell during the early phase of synaptogenesis. While the molecular signals and mechanisms of induction involved remain largely unknown, ultrastructural, physiological and biochemical studies have begun to define a distinct sequence of cellular events triggered by contact with the target muscle cell.