|
|
||||||||
The Journal of Neurophysiology Vol. 81 No. 3 March 1999, pp. 1318-1329
Copyright ©1999 by the American Physiological Society
1Nobel Institute for Neurophysiology,
Tegnér, Jesper and
Sten Grillner.
Interactive effects of the GABABergic
modulation of calcium channels and calcium-dependent potassium channels
in lamprey. The GABAB-mediated modulation of
spinal neurons in the lamprey is investigated in this study. Activation
of GABAB receptors reduces calcium currents through both
low- (LVA) and high-voltage activated (HVA) calcium channels, which
subsequently results in the reduction of the calcium-dependent
potassium (KCa) current. This in turn will reduce the peak
amplitude of the afterhyperpolarization (AHP). We used the modulatory
effects of GABAB receptor activation on N-methyl-D-aspartate (NMDA)-induced,
TTX-resistant membrane potential oscillations as an experimental model
in which to separate the effects of GABAB receptor
activation on LVA calcium channels from that on KCa
channels. We show experimentally and by using simulations that a direct
effect on LVA calcium channels can account for the effects of
GABAB receptor activation on intrinsic membrane potential oscillations to a larger extent than indirect effects mediated via
KCa channels. Furthermore, by conducting experiments and
simulations on intrinsic membrane potential oscillations, we find that
KCa channels may be activated by calcium entering through
LVA calcium channels, providing that the decay kinetics of the calcium
that enters through LVA calcium channels is not as slow as the calcium entering via NMDA receptors. A combined experimental and computational analysis revealed that the LVA calcium current also contributes to
neuronal firing properties.
This article has been cited by other articles:
![]() |
M. Huss, A. Lansner, P. Wallen, A. El Manira, S. Grillner, and J. H. Kotaleski Roles of Ionic Currents in Lamprey CPG Neurons: A Modeling Study J Neurophysiol, April 1, 2007; 97(4): 2696 - 2711. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Alford, E. Schwartz, and G. V. Di Prisco The Pharmacology of Vertebrate Spinal Central Pattern Generators Neuroscientist, June 1, 2003; 9(3): 217 - 228. [Abstract] [PDF] |
||||
![]() |
A. Monteil, J. Chemin, E. Bourinet, G. Mennessier, P. Lory, and J. Nargeot Molecular and Functional Properties of the Human alpha 1G Subunit That Forms T-type Calcium Channels J. Biol. Chem., February 25, 2000; 275(9): 6090 - 6100. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |