GYKI 52466 antagonizes glutamate responses but not NMDA and kainate responses in rat abducens motoneurones.
A new non-N-methyl-D-aspartate (non-NMDA) glutamate receptor antagonist, GYKI 52466, was tested on L-glutamate (Glu)-, kainate (KAI)- and NMDA-induced responses in vivo, using both extracellular recording of antidromic field potentials and intracellular recording from rat abducens motoneurones. Intravenous (5-10 mg/kg) or iontophoretic applications of GYKI 52466 blocked the Glu-induced depression of antidromic field potentials only. Furthermore, intravenous application of ketamine blocked the NMDA-induced depression only. Iontophoretic application of GYKI 52466 reduced the Glu-induced neuronal depolarization but not those induced by NMDA and KAI. Our results show a selective blockade of Glu responses by GYKI 52466, probably by acting at the AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptor subtype in rat abducens motoneurones.
Ouardouz
M
M
Unité de Neurocybernétique Cellulaire, CNRS URA 634, Marseilles, France.
Durand
J
J
D000010:Abducens Nerve / Q000502:physiology*; D000818:Animals; D014151:Anti-Anxiety Agents; D001569:Benzodiazepines / Q000494:pharmacology*; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates / Q000494:pharmacology*; D007608:Kainic Acid / Q000494:pharmacology*; D008297:Male; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D016202:N-Methylaspartate / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects*
D014151:Anti-Anxiety Agents; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates; D016194:Receptors, N-Methyl-D-Aspartate; C061950:GYKI 52466; D001569:Benzodiazepines; D016202:N-Methylaspartate; D007608:Kainic Acid