Response to novelty, social and self-control behaviors, in rats exposed to neonatal anoxia: modulatory effects of an enriched environment.
Perinatal asphyxia is a concern for public health and may promote subtle and long-lasting neuropsychiatric disorders. In the present study, newborn Wistar rat pups underwent a repeated 20-min exposure to a 100% N2 atmosphere (or air) on postnatal days (pnd) 1, 3, 5, and 7. Half of the animals were housed during adolescence (pnd 21-35) in an enriched environment. The consequences on behavior were assessed throughout adolescence to adulthood. When scored for social performance, adolescent rats exposed to neonatal asphyxia exhibited exaggerated levels of anogenital sniffing behavior, which was normalized by enriched living. In air-exposed controls, enriched living increased the expression of affiliative and novelty-seeking behaviors, as compared to standard housing. However, this enrichment-induced behavioral plasticity was not found in rats neonatally exposed to asphyxia. At adulthood, levels of impulsivity and 5-HT2A receptors in the striatum were markedly increased in neonatal-asphyxia rats kept in standard-housing conditions. Interestingly, impulsivity and receptor density were normalized by enriched rearing during adolescence. These findings indicate profound long-lasting behavioral alterations as a consequence of repeated neonatal asphyxia in rats. Beneficial effects of stimulation by an enriched environment during the still-plastic window of adolescence are suggested in these animals.
Adriani
Walter
W
Section of Behavioural Neuroscience, Department Cell Biology and Neurosciences, Istituto Superiore di Sanità, viale Regina Elena 299, 00161, Rome, Italy.
Giannakopoulou
Dimitra
D
Bokulic
Zvonimir
Z
Jernej
Branimir
B
Alleva
Enrico
E
Laviola
Giovanni
G
D000818:Animals; D000831:Animals, Newborn; D001237:Asphyxia / Q000523:psychology*; D004777:Environment; D005106:Exploratory Behavior; D005260:Female; D006799:Housing, Animal; D007175:Impulsive Behavior / Q000523:psychology*; D007398:Interpersonal Relations; D011247:Pregnancy; D051381:Rats; D044402:Receptor, Serotonin, 5-HT2A / Q000187:drug effects / Q000502:physiology; D012919:Social Behavior; D012931:Social Environment; D016019:Survival Analysis; D015430:Weight Gain / Q000502:physiology
D044402:Receptor, Serotonin, 5-HT2A