Abstract
Miniature inhibitory postsynaptic potentials (mIPSP) of motoneurons in isolated frog spinal cord were recorded in conditions of blockade of the conduction of nerve spikes and ionotropic glutamate receptors (TTX, 1 µM, CNQX, 25 µM, D-AP5, 50 µM). Three types of mIPSP were identified: those with fast and slow time characteristics and mIPSP with two-component decays. Two-component mIPSP accounted for 8.7% of all selected responses, fast mIPSP for 64.5%, and slow mIPSP for 26.8%. Blockade of GABAA receptors with bicuculline (20 µM) led to decreases in the numbers of slow and two-component mIPSP and an increase in the number of mIPSP with fast kinetics. Strychnine (1 µM), a blocker of glycine receptors, led to a reduction in the number of fast receptors and an increase in the number of slow potentials. These data suggest that frog spinal cord motoneurons have three types of inhibitory mIPSP, mediated by GABA, glycine, and simultaneous release of these two transmitters from the same presynaptic terminals.
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N. P. Veselkin and V. O. Adanina, “The morphological substrate of inhibition in the spinal cord of the lamprey and frog,” in: Proceedings of the International Conference on Current Questions in the Physiology and Biochemistry of Aqueous Organisms [in Russian], Petrozavodsk (2004).
V. M. Kozhanov, O. A. Karamyan, N. M. Chmykhova, N. P. Veselkin, and G. P. Klemann, “Modulation of miniature inhibitory potentials in spinal cord motoneurons in tortoises by group II metabotropic glutamate receptors,” Tsitologiya, 46, No. 4, 326–336 (2004).
V. M. Kozhanov, O. A. Karamyan, N. M. Chmykhova, and N. P. Veselkin, “Modulation of miniature spontaneous synaptic activity in frog spinal cord motoneurons by metabotropic glutamate receptors,” in: Proceedings of the 19th Congress of the I. P. Pavlov Physiological Society, Ros. Fiziol. Zh. im. I. M. Sechenova, 90, No. 8, 408–409 (2004).
G. G. Kurchavyi, “Amplitude of miniature potentials in motoneurons of the fog Rana ridibunda,” Zh. Évolyuts. Biokhim. Fiziol, 20, No. 5, 504–510 (1984).
Z. É. Mel’yan and V. M. Kozhanov, “The effects of metabotropic glutamate receptors on the duration of post-tetanic changes in post-synaptic potentials in motoneurons of the frog Rana ridibunda,” Zh. Évolyuts. Biokhim. Fiziol, 33, No. 4–5, 475–483 (1997).
A. V. Sem’yanov, “GABAergic inhibition in the CNS: types of GABA receptors and the mechanism of tonic GABA-mediated inhibitory action,” Neirofiziologiya, 34, No. 1, 82–92 (2002).
N. Ankri, P. Legendre, D. S. Faber, and H. Korn, “Automatic detection of spontaneous synaptic responses in central neurons,” J. Neurosci. Meth, 52, No. 1, 87–100 (1994).
N. Chery and Y. De Konick, “Junctional versus extrajunctional glycine and GABAA receptor-mediated IPSCs in identified lamina I neurons of the adult rat spinal cord,” J. Neurosci, 19, No. 17, 7342–7355 (1999).
R. Donato and A. Nistri, “Relative contribution by GABA or glycine to Cl mediated synaptic transmission on rat hypoglossal motoneurons in vitro,” J. Neurophysiol, 84, 2715–2724 (2000).
A. Dumoulin, P. Rostaing, C. Bedet, M.-F. Isambert, J.-P. Henry, A. Triller, and B. Gasnier, “Presence of the vesicular inhibitory amino acid transporter in GABAergic and glycinergic synaptic terminal boutons,” J. Cell Sci, 112, 811–823 (1999).
A. Dumoulin, A. Triller, and S. Dieudonne, “IPSC kinetics at identified GABAergic and mixed GABAergic and glycinergic synapses onto cerebellar Golgi cells,” J. Neurosci, 21, No. 16, 6045–6057 (2001).
B.-X. Gao, C. Stricker, and L. Ziskind-Conhaim, “Transition from GABAergic to glycinergic synaptic transmission in newly formed spinal networks,” J. Neurophysiol., 86, 492–502 (2001).
P. Jonas, J. Bischofberger, and J. Sandkuhler, “Corelease of two fast neurotransmitters at a central synapse,” Science, 281, 419–424 (1998).
J. A. O’Brien and A. J. Berger, “Cotransmission of GABA and glycine to brain stem motoneurons,” J. Neurophysiol., 82, 1638–1641 (1999).
M. Russier, I. L. Kopysova, N. Ankri, N. Ferrand, and D. Dehanne, “GABA and glycine co-release optimizes functional inhibition in rat brainstem motoneurons in vitro,” J. Physiol., 541, No. 1, 123–137 (2002).
A. J. Todd, C. Watt, R. C. Spike, and W. Sieghart, “Colocalization of GABA, glycine, and their receptors at synapses in the rat spinal cord,” J. Neurosci., 16, No. 3, 974–982 (1996).
A. Triller, F. Cluzeaud, and H. Korn, “Gamma-Aminobutyric acid-containing terminals can be apposed to glycine receptors at central synapses,” J. Cell. Biol., 104, 947–956 (1987).
N. P. Vesselkin, J. P. Rio, V. O. Adanina, and J. Reperant, “GABA-and glycine-immunoreactive terminals contacting motoneurons in lamprey spinal cord,” J. Chem. Neuroanat., 19, No. 2, 69–80 (2000).
L.-J. Wu, Y. Li, and T.-L. Xu, “Co-release and interaction of two inhibitory co-transmitters in rat sacral dorsal commissural neurons,” NeuroReport, 13, 977–981 (2002).
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Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 92, No. 1, pp. 18–26, January, 2006.
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Polina, Y.A., Amakhin, D.V., Kozhanov, V.M. et al. Three types of inhibitory miniature potentials in frog spinal cord motoneurons: Possible GABA and glycine cotransmission. Neurosci Behav Physiol 37, 271–276 (2007). https://doi.org/10.1007/s11055-007-0011-x
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DOI: https://doi.org/10.1007/s11055-007-0011-x