title: Environmental enrichment does not reverse the effects of maternal deprivation on NMDAR and Balb/c mice behaviors.
abstract: Early adverse life experiences have been associated with anxiety-like behavior and memory impairment. N-methyl-d-aspartate receptors (NMDARs) play an important role in brain development. Enriched environments are known to positively influence emotional and cognitive functions in the brain. We examined the effects of maternal deprivation (MD) on NMDAR subunits in the hippocampus, locomotor activity, anxiety behaviors, and learning-memory performance of Balb/c mice. We also examined whether these effects could be reversed by raising the offspring in an enriched environment. The mice were separated from their mothers for a single 24h episode on postnatal day (PND) 9. The mice were weaned on day 21 and were housed under either standard (SE) or enriched (EE) environmental conditions. Emotional behaviors and cognitive processes of mice were evaluated using an open field (OF) test, an elevated plus maze (EPM) test, and a Morris water-maze (MWM). NMDAR subunits (GluN1, GluN2A, and GluN2B) mRNA expression levels in the hippocampus were examined by real-time PCR. In OF, MD had no effect on horizontal locomotor activity. MD increased anxiety-like behaviors in the EPM and decreased spatial learning performance in MWM; however, these effects were not reversed by EE. MD (in SE and EE conditions) increased GluN1, GluN2A, and GluN2B mRNA expressions in the hippocampus. In conclusion, MD led to the deterioration of the emotional and cognitive processes during adulthood. Moreover, environmental enrichment did not reverse the deleterious effects of the MD on emotional and cognitive functions and increased the NMDAR levels.
authors: Division of Neurophysiology, Department of Physiology, Medical Faculty, University of Çukurova, Balcali, 01330 Adana, Turkey. Electronic address: kakillioglu@cu.edu.tr.
authors: Kubra
authors: K
authors: Akillioglu
authors: Department of Medical Biology and Genetics, Medical Faculty, University of Çukurova, Balcali, 01330 Adana, Turkey.
authors: M Bertan
authors: MB
authors: Yilmaz
authors: Department of Physiology, Medical Faculty, University of Çukurova, Balcali, 01330 Adana, Turkey.
authors: Ayper
authors: A
authors: Boga
authors: Division of Neurophysiology, Department of Physiology, Medical Faculty, University of Çukurova, Balcali, 01330 Adana, Turkey.
authors: Secil
authors: S
authors: Binokay
authors: Department of Medical Biology and Genetics, Medical Faculty, University of Çukurova, Balcali, 01330 Adana, Turkey.
authors: Sabriye
authors: S
authors: Kocaturk-Sel
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight; D004777:Environment; D005786:Gene Expression Regulation / Q000502:physiology; D006624:Hippocampus / Q000378:metabolism; D008426:Maternal Deprivation; D018782:Maze Learning / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D019964:Mood Disorders / Q000209:etiology* / Q000473:pathology; D011597:Psychomotor Performance; D012333:RNA, Messenger / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate
keywords: Environmental enrichment; Hippocampus; Maternal deprivation; NMDA receptor