Quantitative measurement of glutamate receptor subunit protein expression in the postnatal rat spinal cord.
Glutamate is the major excitatory neurotransmitter in the CNS and its effects on neurons are dependent on the type and composition of glutamate receptors with which it interacts. In this study, the protein expression levels of several ionotropic glutamate receptor subunits (N-methyl-D-aspartate (NMDA) subunits NR1, NR2A, NR2B, and alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) receptor subunits GluR1, GluR2, GluR4) were quantified in particulate preparations from rat spinal cord at various ages after birth. We found that all six subunits showed high expression in the early postnatal period, followed by a subsequent decline as the rats matured to adults. The levels of two subunits (NR2A and GluR4) were found to initially increase during the first postnatal week prior to the decline to adult levels. The high levels of expression observed of these subunits in the early postnatal period may have implications for mechanisms of neural injury and cell death in the immature nervous system that involve cation influx through ionotropic glutamate receptors.
Brown
Kwame M
KM
Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, 3900 Reservoir Rd, Washington, DC 20007, USA. brownk4@georgetown.edu
Wrathall
Jean R
JR
Yasuda
Robert P
RP
Wolfe
Barry B
BB
D000375:Aging / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D002454:Cell Differentiation / Q000502:physiology*; D015536:Down-Regulation / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D013116:Spinal Cord / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D013119:Spinal Cord Injuries / Q000378:metabolism / Q000503:physiopathology; D009435:Synaptic Transmission / Q000502:physiology; D015854:Up-Regulation / Q000502:physiology
D018698:Glutamic Acid; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; C409466:NR1 NMDA receptor; C120997:NR2A NMDA receptor; C121001:NR2B NMDA receptor; C104724:glutamate receptor ionotropic, AMPA 4; C104722:glutamate receptor ionotropic, AMPA 2