Excitatory amino acid receptor subtype binding following traumatic brain injury.
Sprague-Dawley rats were subjected to a moderate level (2.2 atm) of traumatic brain injury (TBI) using fluid percussion. Injured animals were allowed post-trauma survival periods of 5 min, 3 and 24 h. Regional glutamate receptor subtype binding was assessed with quantitative autoradiography in each group for N-methyl-D-aspartate (NMDA), quisqualate and kainate receptor subpopulations at approximately the -3.8 bregma level and compared to a sham control group. [3H]glutamate binding to the NMDA receptor was significantly (P less than 0.05) decreased at 3 h post-TBI in the hippocampal CA1 stratum radiatum, the molecular layers of the dentate gyri and the outer (layers 1-3) and inner (layers 5 and 6) overlying neocortex. NMDA receptor binding was significantly reduced in layers 5 and 6 of the neocortex at all post-trauma survival times but no further differences were seen in the hippocampi. No significant changes were observed with [3H]AMPA binding to quisqualate receptors and [3H]KA binding was significantly reduced only in layers 5 and 6 of the neocortex at 24 h after TBI. These data further confirm the pathological involvement of the NMDA receptor complex in brain regions selectively vulnerable to moderate levels of TBI in this model.
Miller
L P
LP
Neuroscience Laboratory, Veterans Administration Medical Center, Washington, DC 20422.
Lyeth
B G
BG
Jenkins
L W
LW
Oleniak
L
L
Panchision
D
D
Hamm
R J
RJ
Phillips
L L
LL
Dixon
C E
CE
Clifton
G L
GL
Hayes
R L
RL
D000818:Animals; D001930:Brain Injuries / Q000378:metabolism*; D007608:Kainic Acid; D010069:Oxadiazoles; D051381:Rats; D011919:Rats, Inbred Strains; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D017981:Receptors, Neurotransmitter / Q000378:metabolism*
D007608:Kainic Acid; D010069:Oxadiazoles; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter