Functional maturation of the neocortex

Abstract

Is a dialogue between neurophysiological research and psychiatric research possible? It is possible that such an exchange would allow us to understand what makes our brain “human”? We are able to identify two fundamental moments in the functional development of the cortex: the 24th week and the moment of birth. At the 24th week, with the formation of the subplate zone and the retina, the capacity to react appears, allowing the foetus, in case of birth, to react to the luminous stimulation. There is at the moment of birth a real and proper break between the foetal state and the neonatal state. From the physiological point of view this difference is characterized by the activation of the immediate early genes by sensorial stimulation, the activation of the cerebral cortex through the locus coeruleus by luminous stimulation, by the switch of the neurotransmitters through the formation of the inhibitory and excitatory systems. The two physiological concepts of inhibition and excitation are surpassed in the creation of a different temporal organization among the neuronal populations. At the moment of birth there is a rapid passage from foetal endogenous neural activity that expresses itself through SATs tracing, to one that is stimulus-induced and expresses itself with the onset of continuous oscillatory activity. This neurophysiological data confirms what has been theorized, following a deductive method, by Massimo Fagioli, that when the light stimulates the retina, at the moment of birth, the cerebral cortex is activated.