The theme of this work (development of the nervous system and its culminating processes, synaptogenesis and neuroplasticity) is very broad, and can be approached with different classification criteria. The review presented in this work, which is not intended to be exhaustive at all, has been carried out based on the groups of signaling molecules. However, whatever the categories that serve as a basis for ordering the subject, inevitably the point is reached that “everything depends on everything”, that is, there is a general interdependence and interrelation that connects all the molecules and pathways, The following chapters present a brief synthesis of the most important signaling molecules involved, as far as is known, in neurodevelopment, and an analysis of their convergence and divergence patterns, to conclude with some conclusions from the integrative physiological perspective. Interpretation from a physiological perspective seeks to make sense of all these networks of interdependence of processes in neurodevelopment, in order to achieve a vision that transcends the chemical and contributes to the understanding of the complex properties of the nervous system.