Early impoverished environment delays the maturation of cerebral cortex

• Published in: Scientific reports Vol. 8; no. 1; pp. 1187 - 15
• Main Authors: Narducci, Roberta, Baroncelli, Laura, Sansevero, Gabriele, Begenisic, Tatjana, Prontera, Concetta, Sale, Alessandro, Cenni, Maria Cristina, Berardi, Nicoletta, Maffei, Lamberto
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19.01.2018; Nature Publishing Group
• Subjects: 14/1; 14/34; 14/63; 59; 631/378/2571/1696; 631/378/3920; 64; 64/60; 9/30; Acuity; Animals; Axons - metabolism; Biomarkers; Body Weight; Central nervous system; Cerebral cortex; Cerebral Cortex - growth & development; Cerebral Cortex - metabolism; Cerebral Cortex - physiology; Evoked Potentials, Visual; Female; Fibers; Humanities and Social Sciences; Insulin; Insulin-like growth factor I; Insulin-Like Growth Factor I - metabolism; Insulin-like growth factors; Juveniles; Latency; Living conditions; Male; Maternal-Fetal Relations; Maturation; Memory; Motor Activity; multidisciplinary; Myelin Sheath - metabolism; Myelination; Nervous system; Neurogenesis; Neurons - metabolism; Phosphorylation; Rats; Science; Sensorimotor integration; Somatosensory cortex; Visual Acuity; Visual Cortex; Visual evoked potentials; Visual pathways; Visual stimuli; Visual system; γ-Aminobutyric acid
• DOI: 10.1038/s41598-018-19459-y
• ISSN: 2045-2322

The influence of exposure to impoverished environments on brain development is unexplored since most studies investigated how environmental impoverishment affects adult brain. To shed light on the impact of early impoverishment on developmental trajectories of the nervous system, we developed a protocol of environmental impoverishment in which dams and pups lived from birth in a condition of reduced sensory-motor stimulation. Focusing on visual system, we measured two indexes of functional development, that is visual acuity, assessed by using Visual Evoked Potentials (VEPs), and VEP latency. In addition, we assessed in the visual cortex levels of Insulin-Like Growth Factor 1 (IGF-1) and myelin maturation, together with the expression of the GABA biosynthetic enzyme GAD67. We found that early impoverishment strongly delays visual acuity and VEP latency development. These functional changes were accompanied by a significant reduction of IGF-1 protein and GAD67 expression, as well as by delayed myelination of nerve fibers, in the visual cortex of impoverished pups. Thus, exposure to impoverished living conditions causes a significant alteration of developmental trajectories leading to a prominent delay of brain maturation. These results underscore the significance of adequate levels of environmental stimulation for the maturation of central nervous system.