AUTHOR=Polese Daniela , Riccio Maria Letizia , Fagioli Marcella , Mazzetta Alessandro , Fagioli Francesca , Parisi Pasquale , Fagioli Massimo 

TITLE=The Newborn's Reaction to Light as the Determinant of the Brain's Activation at Human Birth

JOURNAL=Frontiers in Integrative Neuroscience

VOLUME=Volume 16 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/integrative-neuroscience/articles/10.3389/fnint.2022.933426

DOI=10.3389/fnint.2022.933426

ISSN=1662-5145

ABSTRACT=Developmental neuroscience research has not yet fully unveiled the dynamics involved in human birth. The trigger of the first breath, often assumed to be the marker of human life, has not been characterized, nor has brain modification or activation at birth been clarified. Few researchers only have considered the impact of extrauterine environment, with its strong stimuli, on birth. This ‘hypothesis and theory’ article hints at the role of a specific stimulus activating the central nervous system (CNS), at human birth. The stimulus must have specific features though, such as novelty, efficacy, ubiquity and immediacy. We propose light as a robust candidate for activating the CNS via the retina.
Available information about fetal and neonatal neurodevelopment, in particular with reference to retinal light responsive pathways, will be examined together with GABA functional switch, and the subplate disappearance, which, at experimental level, characterize the neonatal brain differently from the fetal brain.
In this work, we assume how a very rapid activation of retinal photoreceptors at birth initiates a sudden brain shift from the prenatal pattern of functions to the neonatal set-up. Our assumption implies the presence of a photoreceptor capable of capturing and transducing light/photon stimulus, transforming it into an effective signal for the activation of new brain functions at birth. Opsin photoreception and, more specifically, melanopsin-dependent photoreception, which is provided by intrinsically photosensitive retinal ganglion cells (ipRGCs), is considered as a valid candidate.
Although what assumed herein cannot be verified in humans based on knowledge so far, indeed, proposing an important and novel function can trigger a broad-range diversified research in different domains, from neurophysiology to neurology and psychiatry.