Real-time measurement of glutamate release from the ischemic penumbra of the rat cerebral cortex using a focal middle cerebral artery occlusion model.
Following permanent middle cerebral artery occlusion, extracellular penumbral glutamate levels, measured by a real-time glutamate electrode, increased in two different patterns. In 7/11 rats, glutamate increased from baseline levels of 19+/-4 (mean+/-SEM) to 208+/-29 microM and then declined towards baseline levels. Blood flow in the penumbral area declined to 30% of pre-ischemic levels with recovery to 60 and 70% of baseline values by 3 and 6 h, respectively. Four of 11 rats in the study also exhibited late peaks of glutamate release (120+/-40 microM ) 2 h after the onset of ischemia. There were no changes in the EEG recordings or cerebral blood flow during these late glutamate peaks.
Guyot
L L
LL
Department of Neurological Surgery, Wayne State University, 540 East Canfield, Detroit, MI 48201, USA.
Diaz
F G
FG
O'Regan
M H
MH
McLeod
S
S
Park
H
H
Phillis
J W
JW
D000818:Animals; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D013181:Cortical Spreading Depression / Q000502:physiology; D004195:Disease Models, Animal; D004566:Electrodes; D004569:Electroencephalography; D018698:Glutamic Acid / Q000378:metabolism*; D020244:Infarction, Middle Cerebral Artery / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D018698:Glutamic Acid