Neural activity in early brain development : beyond the innate and the acquired

The brain is an organ that develops in several sequential phases, well described by psychologists and neurobiologists alike. Within it, the circuits that form the cerebral cortex, and control sensory perception, motor responses and cognitive functions, are built up in stages. These stages include the maturation of neurons with different properties, the remodeling or elimination of transient circuits and neurons, and the refinement of connections that ultimately lead to the assembly of complex circuits essential to adult cortical function. It has long been known that neuronal activity induced by what individuals experience is essential for refining or adapting brain circuits pre-wired during prenatal life, in parallel with the distinction commonly made between innate and acquired.
However, numerous studies, including very recent ones, show that neuronal activity is involved in the self-organization of brain circuits from prenatal stages onwards, enabling functional circuits to be wired and adapted to the body, the organism and then the external world. These studies highlight temporal windows of adaptation of brain circuits under physiological and pathological conditions, from plasticity to neurodevelopmental disorders.