Title
Impact of neonatal anoxia and hypothermic treatment on development and memory of rats
Date Issued
01 June 2021
Access level
open access
Resource Type
journal article
Author(s)
Tejada M.B.
Motta-Teixeira L.C.
Ikebara J.M.
Cardoso D.S.
Machado-Nils A.V.
Lee V.Y.
Diccini I.
Arruda B.P.
Martins P.P.
Dias N.M.M.
Tessarotto R.P.
Raeisossadati R.
Bruno M.
Takase L.F.
Kihara A.H.
Nogueira M.I.
Xavier G.F.
Takada S.H.
Universidade de São Paulo
Publisher(s)
Academic Press Inc.
Abstract
Therapeutic hypothermia (TH) is well established as a standard treatment for term and near-term infants. However, therapeutic effects of hypothermia following neonatal anoxia in very premature babies remains inconclusive. The present rodent model of preterm neonatal anoxia has been shown to alter developmental milestones and hippocampal neurogenesis, and to disrupt spatial learning and memory in adulthood. These effects seem to be reduced by post-insult hypothermia. Epigenetic-related mechanisms have been postulated as valuable tools for developing new therapies. Dentate gyrus neurogenesis is regulated by epigenetic factors. This study evaluated whether TH effects in a rodent model of preterm oxygen deprivation are based on epigenetic alterations. The effects of TH on both developmental features (somatic growth, maturation of physical characteristics and early neurological reflexes) and performance of behavioral tasks at adulthood (spatial reference and working memory, and fear conditioning) were investigated in association with the possible involvement of the epigenetic operator Enhancer of zeste homolog 2 (Ezh2), possibly related to long-lasting effects on hippocampal neurogenesis. Results showed that TH reduced both anoxia-induced hippocampal neurodegeneration and anoxia-induced impairments on risk assessment behavior, acquisition of spatial memory, and extinction of auditory and contextual fear conditioning. In contrast, TH did not prevent developmental alterations caused by neonatal anoxia and did not restore hippocampal neurogenesis or cause changes in EZH2 levels. In conclusion, despite the beneficial effects of TH in hippocampal neurodegeneration and in reversing disruption of performance of behavioral tasks following oxygen deprivation in prematurity, these effects seem not related to developmental alterations and hippocampal neurogenesis and, apparently, is not caused by Ezh2-mediated epigenetic alteration.
Volume
340
Language
English
OCDE Knowledge area
Neurología clínica
Subjects
Scopus EID
2-s2.0-85102598599
PubMed ID
Source
Experimental Neurology
ISSN of the container
00144886
Sponsor(s)
This work was supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP): project grants to S.H.T. ( 2018/14072-7 ), M.I.N. ( 2015/18415-8 ), A.H.K. ( 2017/26439-0 ) and fellowships to L.C.M.T. ( 2016/18941-4 ) and P.P.M. ( 2018/06731-0 ); Coordination for the Improvement of Higher Education Personnel (CAPES) of Brazil : fellowships to V.D.V.M. and V.Y.L.; International Brain Research Organization (IBRO) : fellowships to M.B.T. and V.D.V.M.; National Scientific and Technical Research Council (CONICET) of Argentina and the Secretary of Science, Technology and Innovation (SECITI) of San Juan, Argentina .
We gratefully thank Kelly Patricia Nery Borges and Manoel Brito, for technical support. Special thanks to Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and National Council for Scientific and Technological Development (CNPq).
Sources of information:
Directorio de Producción Científica
Scopus