Glutamate receptors in the terminal nerve gonadotropin-releasing hormone neurons of the dwarf gourami (teleost).
The terminal nerve (TN)-gonadotropin-releasing hormone (GnRH) system has been suggested to function as a neuromodulatory system that regulates the motivational state of the animal. To investigate the synaptic control of activities of the TN-GnRH neurons, we analyzed electrophysiologically the type of glutamate receptors (GluRs) in the TN-GnRH neurons. By using various specific GluR agonists and antagonists, we found that they have ionotropic GluRs (iGluR; non-NMDAR and NMDAR) and group 3 metabotropic GluRs. However, in the combined presence of supramaximal concentration of iGluR blockers in the perfusing solution and the GDPbetaS in the patch pipette, there were still residual Glu-induced depolarizing responses. These results suggest the presence of a novel type of iGluRs, in addition to the conventional GluRs, in the TN-GnRH neurons.
Kiya
Taketoshi
T
Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo, Kanagawa 238-0225, Japan.
Oka
Yoshitaka
Y
D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004347:Drug Interactions; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D005260:Female; D005399:Fishes / Q000378:metabolism; D018698:Glutamic Acid / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009431:Neural Conduction / Q000187:drug effects; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D018408:Patch-Clamp Techniques / Q000379:methods; D017470:Receptors, Glutamate / Q000187:drug effects / Q000378:metabolism*; D013873:Thionucleotides / Q000494:pharmacology
D000779:Anesthetics, Local; D004338:Drug Combinations; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D017470:Receptors, Glutamate; D013873:Thionucleotides; D006153:Guanosine Diphosphate; D007987:Gonadotropin-Releasing Hormone; D018698:Glutamic Acid; C023427:guanosine 5'-O-(2-thiodiphosphate)