Modulation of tau neuronal expression induced by NMDA, non-NMDA and metabotropic glutamate receptor agonists.
We have analysed changes in tau protein immunoreactivity in rat embryonic neurons degenerating in response to treatment with N-methyl-D-aspartate (NMDA), non-NMDA and metabotropic agonists. Glutamate agonists were applied in Mg(++)-free and glycine-supplemented medium 8 days after initial plating. Cell viability was assessed by fluorescein diacetate staining and neuronal survival was evaluated by cell counting. Immunocytochemical and confocal laser microscopic studies used a tau2 monoclonal antibody. Acute and chronic NMDA treatment induced a concentration-dependent increase in intraneuronal tau immunoreactivity. Increased tau immunolabelling during chronic NMDA toxicity was dramatically attenuated by tetrodotoxin and also by 6-cyano-7-nitroquinoxaline-2,3-dione. Non-NMDA and metabotropic receptor agonist treatment produced a weaker augmentation in tau2 immunoreactivity. These findings suggest that, in this model, glutamate-receptor and sodium-channel coactivation are together needed to produce changes in tau immunoreactivity.
Couratier
P
P
Unité de Neurobiologie Cellulaire, Faculté de Médecine, Limoges, France.
Sindou
P
P
Tabaraud
F
F
Diop
A G
AG
Spencer
P S
PS
Hugon
J
J
D000704:Analysis of Variance; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016291:Dizocilpine Maleate / Q000494:pharmacology; D007124:Immunoenzyme Techniques; D018613:Microscopy, Confocal; D009474:Neurons / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000819:agonists*; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists*; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology; D016875:tau Proteins / Q000032:analysis*
D018091:Receptors, AMPA; D018094:Receptors, Metabotropic Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D016875:tau Proteins; D000001:Calcimycin; D016291:Dizocilpine Maleate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid