title: Pre- and postnatal expressions of NMDA receptors 1 and 2B subunit proteins in the normal rat cortex.
abstract: The NMDA receptor is one of the ionotropic glutamate receptors essential for excitatory neurotransmission and synaptic plasticity. The present study examined the ontogenies of NMDAR1 and NMDAR2B during development (embryonic days: (E) 14, 15, 16, 17 and postnatal days: (P) 0, 5, 10, 20, and 60). The immunoreactivities of both NMDAR1 and NMDAR2B were visualized and semi- quantified simultaneously using batch-matched procedures during the developmental period. In addition, the heteromeric coassembly of NMDAR1 (NR1) and NMDAR2B (NR2B) was analyzed throughout development using immunocoprecipitation blots. Differential developmental expressions were observed between the two NMDA receptor subunits. Although both NR1 and NR2B were already expressed on cortical neurons at E14, NR1 immunoreactivity was lower than NR2B but increased up to P20 then was lower at the last sampling day (P60). By comparison, the high NR2B immunoreactivity at E14 increased until P5, and until the next sample day (P60). Despite the early embryonic protein expressions in prenatal cortex both NR1 and NR2B immunocoprecipitation analyses showed that NR1-NR2B coassembly was not initially detectable until birth (P0), and increased up to P20. This suggests that the physically interactive NMDAR1-2B complex may contribute to the plasticity of early postnatal development characterized by axonal dendritic synaptogenesis.
authors.affiliation: Department of Pediatrics, Wayne State University, The Children's Hospital of Michigan, 3901 Beaubien Avenue, Detroit, MI 48201, USA. t.babb@wayne.edu
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Babb
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Mikuni
authors.forename: Imad
authors.initials: I
authors.lastname: Najm
authors.forename: Christi
authors.initials: C
authors.lastname: Wylie
authors.forename: Mary
authors.initials: M
authors.lastname: Olive
authors.forename: Carrie
authors.initials: C
authors.lastname: Dollar
authors.forename: Hugh
authors.initials: H
authors.lastname: MacLennan
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western / Q000379:methods; D002540:Cerebral Cortex / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D004622:Embryo, Mammalian; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D007150:Immunohistochemistry / Q000379:methods; D047468:Immunoprecipitation / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*
chemical_list: C409466:NR1 NMDA receptor; C121001:NR2B NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate