caa a22 4500 445354208 CHVBK 20180317142854.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s00221-010-2484-z doi (NATIONALLICENCE)springer-10.1007/s00221-010-2484-z Muscarinic inhibition of recurrent glutamatergic excitation in frog tectum column prevents NMDA receptor activation on efferent neuron [Elektronische Daten] [Armantas Baginskas, Antanas Kuras] It is widely recognized that neuronal network activity can be modulated via activation of nicotinic and muscarinic acetylcholine receptors located pre- and postsynaptically. It was established in our earlier study that the activation of presynaptic nicotinic receptors greatly facilitates the retinotectal glutamatergic transmission. In the present study, we have determined a transmitter of tectal recurrent excitation and explored the effects of muscarinic acetylcholine receptor activation on the recurrent excitation and the activity of frog tectum column in vivo. Discharge of a single retinal ganglion cell was elicited by a minimal electrical stimulation of the retina. Evoked activity of the tectum column was recorded using the carbon-fiber microelectrode inserted into the tectum layer F. We found the following: 1. The recurrent excitation in the tectum column was not affected by d-tubocurarine (10μM) and was greatly depressed by the kynurenic acid (500μM), demonstrating glutamatergic nature of the recurrent excitation. 2. The glutamatergic recurrent excitation was largely reduced by carbamylcholine (100μM) and oxotremorine-M (10μM), demonstrating that the activation of muscarinic receptors, located, presumably, on the presynaptic terminals of recurrent pear-shaped neurons, inhibits the recurrent excitation in the tectum column. 3. The muscarinic inhibition of glutamatergic recurrent transmission had critical influence on the activity of the tectum column, preventing the generation of an output signal through suppression of the NMDA receptor activation and establishing necessary conditions for returning of the network to its resting state. Springer-Verlag, 2010 Frog tectum nationallicence Synaptic transmission nationallicence Neuron network nationallicence Recurrent excitation nationallicence Cholinergic modulation nationallicence NMDA receptor nationallicence L-type Ca2+ current nationallicence Baginskas Armantas Laboratory of Neurophysiology, Institute for Biomedical Research, Kaunas University of Medicine, Eiveniu 4, 50009, Kaunas, Lithuania aut Kuras Antanas Laboratory of Neurophysiology, Institute for Biomedical Research, Kaunas University of Medicine, Eiveniu 4, 50009, Kaunas, Lithuania aut Experimental Brain Research Springer-Verlag 208/3(2011-02-01), 323-334 0014-4819 208:3<323 2011 208 221 https://doi.org/10.1007/s00221-010-2484-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00221-010-2484-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Baginskas Armantas Laboratory of Neurophysiology, Institute for Biomedical Research, Kaunas University of Medicine, Eiveniu 4, 50009, Kaunas, Lithuania aut NATIONALLICENCE 700 1- Kuras Antanas Laboratory of Neurophysiology, Institute for Biomedical Research, Kaunas University of Medicine, Eiveniu 4, 50009, Kaunas, Lithuania aut NATIONALLICENCE 773 0- Experimental Brain Research Springer-Verlag 208/3(2011-02-01), 323-334 0014-4819 208:3<323 2011 208 221 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer