Quinolinate and kainate neurotoxicity in neostriatal cultures is potentiated by co-culturing with neocortical neurons.
It has been suggested that a disorder in the regulation of excitatory amino acids (EAA) may underlie the loss of neostriatal neurons seen in Huntington's disease. The role of neocortical afferent fibers in determining the EAA sensitivity of neostriatal neurons was assessed by comparing EAA toxicity in co-cultures of neocortex and neostriatum with that of neostriatum alone. In cultures of neostriatum alone, EAAs produced only modest neuronal losses. Kainate, which tended to be the most potent excitotoxin, produced a loss of approximately 30% of the neurons after a 5-min exposure at a 1-mM concentration. In co-cultures, the sensitivity of neostriatal neurons to EAA toxicity was dramatically enhanced; toxicity was increased about two-fold for kainate and quinolinate at millimolar concentrations and as much as 8-fold for quinolinate at micromolar concentrations. The effects of EAA co-incubation with the N-methyl-D-aspartate (NMDA) receptor antagonist, 2-amino-5-phosphonovaleric acid, suggested that the toxic actions of quinolinate, but not kainate, were mediated largely by NMDA receptors.
Galarraga
E
E
Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee, Memphis 38163.
Surmeier
D J
DJ
Kitai
S T
ST
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology* / Q000187:drug effects; D003342:Corpus Striatum / Q000166:cytology* / Q000187:drug effects; D007608:Kainic Acid / Q000633:toxicity*; D009498:Neurotoxins / Q000494:pharmacology; D011725:Pyridines / Q000633:toxicity*; D017378:Quinolinic Acid; D011805:Quinolinic Acids / Q000633:toxicity*; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000187:drug effects*
D009498:Neurotoxins; D011725:Pyridines; D011805:Quinolinic Acids; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D015763:2-Amino-5-phosphonovalerate; D017378:Quinolinic Acid; D007608:Kainic Acid