.Transmitter regulation of plateau properties in turtle motoneurons. Gytis Svirskis and Jorn Hounsgaard. Laboratory of Neurophysiology, Biomedical Research Institute, Kaunas Medical Academy, 3000 Kaunas, Lithuania & Department of Medical Physiology, The Panum Institute, Copenhagen University, Copenhagen DK-2200, Denmark.
APStracts 4:270N, 1997.
ABSTRACT
In motoneurons, generation of plateau potentials is promoted by modulators that block potassium channels. In voltage clamp experiments, using triangular voltage ramp commands, we show that cis-(ñ)-1-aminocyclopentane-1,3- dicarboxylic acid (ACPD) and muscarine promote the generation of plateau potentials by increasing the dihydropyridine sensitive inward current, by increasing the input resistance and by depolarizing the resting membrane potential. Type I metabotropic glutamate receptors (mGluR I) mediate the effects of ACPD. Baclofen suppresses generation of plateau potentials by decreasing the dihydropyridine sensitive inward current, by decreasing the input resistance and by hyperpolarizing the resting membrane potential. These results suggest that membrane properties of motoneurons are continuously modulated by synaptic activity in ways that may have profound effects on synaptic integration and pattern generation. 

Received 5 May 1997; accepted in final form 22 September 1997.
APS Manuscript Number J358-7.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 7 October 1997