|
|
||||||||
The Journal of Neurophysiology Vol. 80 No. 5 November 1998,
pp. 2316-2322
Copyright ©1998 The American Physiological Society
a Savi
,
Neuroscience Programme and Istituto Nazionale Fisica della Materia Unit, International School for Advanced Studies, 34014 Trieste, Italy
Sciancalepore, Marina, Nata
a Savi
, János Györi, and Enrico Cherubini. Facilitation of miniature GABAergic currents by ruthenium red in neonatal rat hippocampal neurons. J. Neurophysiol. 80: 2316-2322, 1998. The whole cell configuration of the patch-clamp technique was used to study the modulation
-aminobutyric acid (GABA)-mediated postsynaptic currents by ruthenium red in CA3 hippocampal neurons in slices obtained from postnatal (P) days P6-P10 old rats. In the presence of kynurenic acid (1 mM), ruthenium red (100 µM) completely blocked stimulus-elicited GABA-mediated postsynaptic currents and reduced by 50% the amplitude of the spontaneous ones. Ruthenium red (100 µM) increased the frequency but not the amplitude of miniature GABAergic currents recorded in the presence of tetrodotoxin (1 µM) and kynurenic acid (1 mM), an effect that was prevented by heparin (100 µM). Ruthenium red did not modify the kinetics of miniature postsynaptic currents and the currents induced by exogenous application of GABA (10 µM) in the presence of tetrodotoxin, suggesting that its action was presynaptic in origin. The effects of ruthenium red on quantal GABA release was independent of external calcium. In a nominally Ca2+-free solution the potentiating effect induced by this polyvalent cation on miniature postsynaptic currents was still present. Intracellular calcium stores were not involved in ruthenium red action, because this polyvalent cation was able to facilitate miniature currents also in the presence of thapsigargin (10-20 µM). These results indicate that ruthenium red has a dual action on GABA release from GABAergic interneurons: it reduces the amplitude of spontaneous events and increases the frequency of miniature currents. The former effect is calcium-dependent, whereas the latter is calcium independent.
This article has been cited by other articles:
![]() |
Y.-C. Yu, L.-H. Cao, and X.-L. Yang Modulation by Brain Natriuretic Peptide of GABA Receptors on Rat Retinal ON-Type Bipolar Cells J. Neurosci., January 11, 2006; 26(2): 696 - 707. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Verkhratsky Physiology and Pathophysiology of the Calcium Store in the Endoplasmic Reticulum of Neurons Physiol Rev, January 1, 2005; 85(1): 201 - 279. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. H. Chang, V. C. Kotak, and D. H. Sanes Long-Term Depression of Synaptic Inhibition Is Expressed Postsynaptically in the Developing Auditory System J Neurophysiol, September 1, 2003; 90(3): 1479 - 1488. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. O. Rizzoli and W. J. Betz Effects of 2-(4-Morpholinyl)-8-Phenyl-4H-1-Benzopyran-4-One on Synaptic Vesicle Cycling at the Frog Neuromuscular Junction J. Neurosci., December 15, 2002; 22(24): 10680 - 10689. [Abstract] [Full Text] [PDF] |
||||
![]() |
Q. Cheng, P. M. Burkat, J. C. Kulli, and J. Yang GABACrho 1 Subunits Form Functional Receptors But Not Functional Synapses in Hippocampal Neurons J Neurophysiol, November 1, 2001; 86(5): 2605 - 2615. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. F. Keller, J. A. M. Coull, N. Chery, P. Poisbeau, and Y. De Koninck Region-Specific Developmental Specialization of GABA-Glycine Cosynapses in Laminas I-II of the Rat Spinal Dorsal Horn J. Neurosci., October 15, 2001; 21(20): 7871 - 7880. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. F. Hoffman and C. R. Lupica Direct Actions of Cannabinoids on Synaptic Transmission in the Nucleus Accumbens: A Comparison With Opioids J Neurophysiol, January 1, 2001; 85(1): 72 - 83. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. F. Hoffman and C. R. Lupica Mechanisms of Cannabinoid Inhibition of GABAA Synaptic Transmission in the Hippocampus J. Neurosci., April 1, 2000; 20(7): 2470 - 2479. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |