Compensatory change in EAAC1 glutamate transporter in rat hippocampus CA1 region during kindling epileptogenesis.
Functional and molecular changes in glutamate transporters during kindling epileptogenesis were investigated in hippocampus CA1-region of rats. In control animals total glutamate transporter activity was indicated by the stimulatory effect of the high-affinity transporter blocker L-trans-pyrrolidine-2,4-dicarboxylate on extracellular glutamate and aspartate concentrations, as measured by in vivo microdialysis. This blocker-induced elevation was absent already early during epileptogenesis. CA1 levels of the glutamate transporter subtypes GLAST and GLT-1, analyzed by quantitative immunoblotting, did not change during kindling epileptogenesis. However, the 60% decrease in EAAC-1 level observed in age-matched controls was fully compensated for in kindled animals 4-5 weeks after the last generalized seizure. These results indicate a compensatory change of the neuronal EAAC-1 glutamate transporter in CA1 region during kindling epileptogenesis, which may be the consequence of a decrease in total transporter activity.
Ghijsen
W E
WE
Institute for Neurobiology, Graduate School for the Neurosciences, University of Amsterdam, The Netherlands. ghijsen@bio.uva.nl
da Silva Aresta Belo
A I
AI
Zuiderwijk
M
M
Lopez da Silva
F H
FH
D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000222:Adaptation, Physiological; D027322:Amino Acid Transport System X-AG; D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D003998:Dicarboxylic Acids / Q000494:pharmacology; D004827:Epilepsy / Q000209:etiology*; D027341:Excitatory Amino Acid Transporter 1; D050580:Excitatory Amino Acid Transporter 3; D005110:Extracellular Space / Q000378:metabolism; D050491:Glutamate Plasma Membrane Transport Proteins; D018698:Glutamic Acid / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism*; D015151:Immunoblotting; D007696:Kindling, Neurologic; D017551:Microdialysis; D011759:Pyrrolidines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D027981:Symporters
D018528:ATP-Binding Cassette Transporters; D027322:Amino Acid Transport System X-AG; D002352:Carrier Proteins; D003998:Dicarboxylic Acids; D027341:Excitatory Amino Acid Transporter 1; D050580:Excitatory Amino Acid Transporter 3; D050491:Glutamate Plasma Membrane Transport Proteins; D011759:Pyrrolidines; C493398:Slc1a1 protein, rat; C493392:Slc1a3 protein, rat; D027981:Symporters; C103758:pyrrolidine-2,3-dicarboxylic acid; D001224:Aspartic Acid; D018698:Glutamic Acid