Maternal dexamethasone and EEG hyperactivity in preterm fetal sheep

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dc.contributor.author Davidson, Joanne en
dc.contributor.author Quaedackers, JSLT en
dc.contributor.author George, Sherly en
dc.contributor.author Gunn, Alistair en
dc.contributor.author Bennet, Laura en
dc.date.accessioned 2012-03-26T01:09:10Z en
dc.date.issued 2011-08 en
dc.identifier.citation JOURNAL OF PHYSIOLOGY-LONDON 589(15):3823-3835 01 Aug 2011 en
dc.identifier.issn 0022-3751 en
dc.identifier.uri http://hdl.handle.net/2292/15291 en
dc.description.abstract Maternal treatment with synthetic corticosteroids such as dexamethasone (DEX) significantly reduces neonatal morbidity and mortality, but its effects on the fetal brain remain unclear. In this study we evaluated the effects of DEX on EEG activity in preterm fetal sheep. Ewes at 103 days gestation received two intramuscular injections of DEX (12 mg, n=8) or saline vehicle (n=7) 24h apart. Fetal EEG activity was recorded from 6h before until 120h after the first injection (DEX-1). DEX-1 was associated with a marked transient rise in total EEG power, maximal at 12h (p<0.001), with a relative increase in delta and reduced theta, alpha, and beta activity, resolving by 24h. Continuous EEG records showed a shift to larger but less frequent transient waveforms (p<0.001). Unexpectedly, evolving epileptiform activity, consistent with electrographic and clinical seizures, developed from 178±44 min after DEX-1. Similar but smaller changes were seen after the second injection. Following the injections, total power returned to control values, but the proportion of alpha activity progressively increased vs. controls (p<0.001), with reduced inter-burst interval duration and number (p<0.001). No histological neural injury or microglial activation was seen. In summary, exposure to maternal dexamethasone was associated with dramatic, evolving low frequency hyperactivity on fetal cortical EEG recordings, followed by sustained changes consistent with maturation of fetal sleep architecture. We postulate that these effects may contribute to improved neonatal outcomes. en
dc.language ENG en
dc.publisher The Physiological Society en
dc.relation.ispartofseries Journal of Physiology en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. Details obtained from http://www.sherpa.ac.uk/romeo/issn/0022-3751/ en
dc.rights.uri https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm en
dc.title Maternal dexamethasone and EEG hyperactivity in preterm fetal sheep en
dc.type Journal Article en
dc.identifier.doi 10.1113/jphysiol.2011.212043 en
pubs.issue 15 en
pubs.begin-page 3823 en
pubs.volume 589 en
dc.rights.holder Copyright: The Physiological Society en
dc.identifier.pmid 21646408 en
pubs.author-url http://jp.physoc.org/content/589/15/3823.abstract en
pubs.end-page 3835 en
pubs.publication-status Published en
dc.rights.accessrights http://purl.org/eprint/accessRights/RestrictedAccess en
pubs.subtype Article en
pubs.elements-id 211011 en
pubs.org-id Medical and Health Sciences en
pubs.org-id Medical Sciences en
pubs.org-id Physiology Division en
dc.identifier.eissn 1469-7793 en
dc.identifier.pii jphysiol.2011.212043 en
pubs.record-created-at-source-date 2011-06-11 en
pubs.dimensions-id 21646408 en


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