title: Adult naked mole-rat brain retains the NMDA receptor subunit GluN2D associated with hypoxia tolerance in neonatal mammals.
abstract: Adult naked mole-rats show a number of systemic adaptations to a crowded underground habitat that is low in oxygen and high in carbon dioxide. Remarkably, brain slice tissue from adult naked mole-rats also is extremely tolerant to oxygen deprivation as indicated by maintenance of synaptic transmission under hypoxic conditions as well as by a delayed neuronal depolarization during anoxia. These characteristics resemble hypoxia tolerance in brain slices from neonates in a variety of mammal species. An important component of neonatal tolerance to hypoxia involves the subunit composition of NMDA receptors. Neonates have a high proportion of NMDA receptors with GluN2D subunits which are protective because they retard calcium entry into neurons during hypoxic episodes. Therefore, we hypothesized that adult naked mole-rats retain a protective, neonatal-like, NMDA receptor subunit profile. We used immunoblotting to assess age-related changes in NMDA receptor subunits in naked mole-rats and mice. The results show that adult naked mole-rat brain retains a much greater proportion of the hypoxia-protective GluN2D subunit compared to adult mice. However, age-related changes in other subunits (GluN2A and GluN2B) from the neonatal period to adulthood were comparable in mice and naked mole-rats. Hence, adult naked mole-rat brain only retains the neonatal NMDA receptor subunit that is associated with hypoxia tolerance.
authors.affiliation: Department of Biological Sciences, University of Illinois at Chicago, 840 West Taylor St., Chicago, IL 60607, USA.
authors.forename: Bethany L
authors.initials: BL
authors.lastname: Peterson
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Park
authors.forename: John
authors.initials: J
authors.lastname: Larson
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000375:Aging / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D005260:Female; D000860:Hypoxia / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D019577:Mole Rats / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*
chemical_list: D016194:Receptors, N-Methyl-D-Aspartate