Simultaneous efflux of endogenous D-ser and L-glu from single acute hippocampus slices during oxygen glucose deprivation.
D-serine and L-glutamate play crucial roles in excitotoxicity through N-methyl-D-aspartate receptor coactivation, but little is known about the temporal profile of efflux during cerebral ischemia. We utilized a newly designed brain slice microperfusion device coupled offline to capillary electrophoresis laser-induced fluorescence to monitor dynamic efflux of endogenous D-ser and L-glu in response to oxygen glucose deprivation (OGD) in single acute hippocampus slices. Efflux profiles with 2-min temporal resolution in response to 24-min OGD show that efflux of D-ser slightly precedes efflux of L-glu by one 2-min sampling interval. Thus both coagonists are available to activate NMDA receptors by the time when glu is released. The magnitude of D-ser efflux relative to baseline values is, however, less than that for L-glu. Peak efflux during OGD, expressed as pre-OGD baseline values, was as follows: D-ser 254% +/- 24%, L-glu 1,675% +/- 259%, L-asp 519% +/- 128%, and L-thr 313% +/- 33%. L-glutamine efflux was shown to decrease significantly in response to OGD. The microperfusion/CE-LIF approach shows several promising attributes for studying endogenous chemical efflux from single, acute brain slices.
Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, USA. fsdlk2@uaf.edu
Daniel L
DL
Kirschner
Ann L
AL
Wilson
Kelly L
KL
Drew
Thomas K
TK
Green
D000208:Acute Disease; D000818:Animals; D015194:Diffusion Chambers, Culture / Q000379:methods; D005947:Glucose / Q000172:deficiency; D018698:Glutamic Acid / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism* / Q000503:physiopathology; D020925:Hypoxia-Ischemia, Brain / Q000378:metabolism* / Q000503:physiopathology; D007536:Isomerism; D008297:Male; D009474:Neurons / Q000378:metabolism; D009924:Organ Culture Techniques; D010100:Oxygen / Q000378:metabolism; D010477:Perfusion / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D012694:Serine / Q000378:metabolism*
D005973:Glutamine; D018698:Glutamic Acid; D012694:Serine; D005947:Glucose; D010100:Oxygen