Synaptic contact between mechanosensory neuron and withdrawal interneuron in terrestrial snail is mediated by l-glutamate-like transmitter

• Published in: Neuroscience letters 2003-05, Vol.341 (3), p.237-240
• Main Authors: Bravarenko, N.I., Korshunova, T.A., Malyshev, A.Y., Balaban, P.M.
• Format: Article
• Language: English
• Subjects: Animals; Excitatory Amino Acid Antagonists - pharmacology; Glutamate; Glutamic Acid - pharmacology; Helix; Helix (Snails) - drug effects; Helix (Snails) - physiology; Helix lucorum; Interneurons - drug effects; Interneurons - physiology; Invertebrates; Mechanoreceptors - drug effects; Mechanoreceptors - physiology; Mechanotransduction, Cellular - drug effects; Mechanotransduction, Cellular - physiology; Monosynaptic connection; Neurons - drug effects; Neurons - physiology; Serotonin; Synapses - drug effects; Synapses - physiology; Synaptic Transmission - drug effects; Synaptic Transmission - physiology; Terrestrial snail
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/S0304-3940(03)00213-1

The properties of the monosynaptic input from mechanosensory neurons to withdrawal interneurons were examined in Helix lucorum. The instantaneous I–V relation of the excitatory postsynaptic current in withdrawal interneurons was nonlinear, having a plateau region between −40 and −60 mV. On application of the blocker of vertebrate N-methyl- d-aspartate (NMDA) receptors AP5, or reduction of the Mg 2+ concentration, the current–voltage relation became more linear, suggesting that Mg 2+ may partially block the ion channel underlying the EPSC at voltages ranging from −40 to around −60 mV and the involvement of NMDA-like receptors. DNQX and 6-cyano-7-nitroquinoxaline-2,3-dione, which are known to block the glutamate non-NMDA receptors in mammals, significantly depress in a dose-dependent manner the actions of the natural transmitter. Exogenous l-glutamate applications mimicked the action of the mechanosensory neuron transmitter.