Fig. 1: The overflowing unmatured brain - a pruning-based window of opportunities.

Although the unmatured brain overflows with synaptic connections, such a developmental program goes beyond any triviality. Excessive synapses are extremely important for the brain to be able to readily fine-tune idiosyncratic connections to the demands of a rather “naïve” brain. In this way, seemingly superfluous connections make the brain prone to adapt, evolve and be molded around the behavioral repertoires that best predict continued future success. Within a concept, the time frame of promiscuous synapses could be understood as a window of opportunity in which the set of actions involving synaptic disconnections would be the tools that really makes this a good and profitable occasion. So, since the very newborn brain beginning, connections are ready to be plastically refined under the guidance of neuronal activities that mirror the nearby niche of an ever-changing environment. Furthermore, from an evolutionary perspective, pruning-based neuronal refinement of a redundant brain is likely a highly conserved mechanism as it can be found from insects to humans.