title: Early postnatal exposure to intermittent hypoxia in rodents is proinflammatory, impairs white matter integrity, and alters brain metabolism.
abstract: BackgroundPreterm infants are frequently exposed to intermittent hypoxia (IH) associated with apnea and periodic breathing that may result in inflammation and brain injury that later manifests as cognitive and executive function deficits. We used a rodent model to determine whether early postnatal exposure to IH would result in inflammation and brain injury.MethodsRat pups were exposed to IH from P2 to P12. Control animals were exposed to room air. Cytokines were analyzed in plasma and brain tissue at P13 and P18. At P20-P22, diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS) were performed.ResultsPups exposed to IH had increased plasma Gro/CXCL1 and cerebellar IFN-γ and IL-1β at P13, and brainstem enolase at P18. DTI showed a decrease in FA and AD in the corpus callosum (CC) and cingulate gyrus, and an increase in RD in the CC. MRS revealed decreases in NAA/Cho, Cr, Tau/Cr, and Gly/Cr; increases in TCho and GPC in the brainstem; and decreases in NAA/Cho in the hippocampus.ConclusionsWe conclude that early postnatal exposure to IH, similar in magnitude to that experienced in human preterm infants, is associated with evidence for proinflammatory changes, decreases in white matter integrity, and metabolic changes consistent with hypoxia.
authors.affiliation: Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA.|Department of Pediatrics, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Darnall
authors.affiliation: Biomedical NMR Research Center, Department of Radiology, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: Biomedical NMR Research Center, Department of Radiology, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA.
authors.forename: Krishnamurthy V
authors.initials: KV
authors.lastname: Nemani
authors.affiliation: Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA.
authors.forename: Chrystelle M
authors.initials: CM
authors.lastname: Sirieix
authors.affiliation: Biomedical NMR Research Center, Department of Radiology, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA.
authors.forename: Barjor
authors.initials: B
authors.lastname: Gimi
authors.affiliation: Department of Pediatrics, Children's National Medical Center and George Washington University, Washington, DC, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Knoblach
authors.affiliation: American SIDS Institute, Naples, FL, USA.
authors.forename: Betty L
authors.initials: BL
authors.lastname: McEntire
authors.affiliation: Department of Pediatrics, Children's National Medical Center and George Washington University, Washington, DC, USA.|Department of Pediatrics, Uniformed Services University, Bethesda, MD, USA.
authors.forename: Carl E
authors.initials: CE
authors.lastname: Hunt
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D001930:Brain Injuries / Q000378:metabolism; D003072:Cognition Disorders; D056324:Diffusion Tensor Imaging; D005260:Female; D000860:Hypoxia / Q000503:physiopathology*; D007249:Inflammation; D008279:Magnetic Resonance Imaging; D051381:Rats; D017207:Rats, Sprague-Dawley; D066127:White Matter / Q000473:pathology*