|
|
||||||||
Journal of Neurophysiology, Vol 72, Issue 1 121-130, Copyright © 1994 by APS
ARTICLES |
N. A. Lambert and W. A. Wilson
Department of Pharmacology, Duke University Medical Center, Durham, North Carolina.
1. Gamma-aminobutyric acid-B (GABAB) autoreceptor-dependent and -independent components of paired-pulse depression (PPD) at inhibitory synapses in area CA3 of the rat hippocampus were studied using whole-cell recording techniques. Inhibitory fibers were activated directly in the presence of the ionotropic glutamate receptor antagonists 6,7-dinitroquinoxaline-2,3,dione (20 microM) and D-2-amino-5-phosphonovalerate (20 microM). 2. When pairs of monosynaptic inhibitory postsynaptic currents (eIPSCs) were evoked with an interstimulus interval of 200 ms, the amplitude of the second response (eIPSC2) was depressed when compared with the first (eIPSC1). The GABAB receptor agonist baclofen (10 microM) depressed both responses, but eIPSC1 was depressed more than eIPSC2, resulting in PPD that was comparatively smaller. Addition of the GABAB receptor antagonist CGP 55845A (1 microM) completely reversed depression of eIPSC1 by baclofen and increased the amplitude of eIPSC2 above the control value, such that PPD in the combination of baclofen and CGP 55845A was equivalent to that in baclofen alone. The ratio eIPSC2/eIPSC1 was 0.64 under control conditions, 0.77 in the presence of baclofen, and 0.79 in the presence of baclofen and CGP 55845A. These results demonstrate the existence of two components of PPD at inhibitory synapses, one that depends on activation of GABAB autoreceptors (GABAB receptor-dependent PPD) and one that does not (GABAB receptor-independent PPD). 3. When the number of inhibitory fibers activated was lowered by decreasing the stimulus intensity, eIPSC2/eIPSC1 was 0.76 under control conditions, 0.75 in the presence of baclofen, and 0.76 in the presence of baclofen and CGP 55845A. These results indicate that GABAB receptor-dependent PPD requires activation of several presynaptic inhibitory neurons, whereas GABAB receptor-independent PPD does not. 4. The time-courses of the GABAB-dependent and -independent components of PPD were compared by varying the interstimulus interval in the absence and presence of CGP 55845A. GABAB-dependent PPD was maximal at an interstimulus interval of 100 ms and was undetectable at 1 s. In contrast, GABAB-independent PPD was maximal at 5 ms and 1 s, was slightly less pronounced at intermediate intervals (50-200 ms), and was present at intervals as long as 5 s. 5. GABAB-independent PPD was not blocked by antagonists at opioid receptors (10 microM naloxone) or muscarinic acetylcholine receptors (10 microM atropine). GABAB-independent PPD could not be accounted for by a decrease in driving force because of Cl- redistribution.(ABSTRACT TRUNCATED AT 400 WORDS)
This article has been cited by other articles:
![]() |
T. Bessaih, L. Bourgeais, C. I. Badiu, D. A. Carter, T. I. Toth, D. Ruano, B. Lambolez, V. Crunelli, and N. Leresche Nucleus-Specific Abnormalities of GABAergic Synaptic Transmission in a Genetic Model of Absence Seizures J Neurophysiol, December 1, 2006; 96(6): 3074 - 3081. [Abstract] [Full Text] [PDF] |
||||
![]() |
S.-L. Liang, G. C. Carlson, and D. A. Coulter Dynamic Regulation of Synaptic GABA Release by the Glutamate-Glutamine Cycle in Hippocampal Area CA1. J. Neurosci., August 15, 2006; 26(33): 8537 - 8548. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. A. Ledoux and C. S. Woolley Evidence That Disinhibition Is Associated with a Decrease in Number of Vesicles Available for Release at Inhibitory Synapses J. Neurosci., January 26, 2005; 25(4): 971 - 976. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. Moore, R. A. Nicoll, and D. Schmitz Adenosine gates synaptic plasticity at hippocampal mossy fiber synapses PNAS, November 25, 2003; 100(24): 14397 - 14402. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. S. Isaacson and H. Vitten GABAB Receptors Inhibit Dendrodendritic Transmission in the Rat Olfactory Bulb J. Neurosci., March 15, 2003; 23(6): 2032 - 2039. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Vreugdenhil, J. G. R. Jefferys, M. R. Celio, and B. Schwaller Parvalbumin-Deficiency Facilitates Repetitive IPSCs and Gamma Oscillations in the Hippocampus J Neurophysiol, March 1, 2003; 89(3): 1414 - 1422. [Abstract] [Full Text] [PDF] |
||||
![]() |
F.-C. Hsu and S. S. Smith Progesterone Withdrawal Reduces Paired-Pulse Inhibition in Rat Hippocampus: Dependence on GABAA Receptor alpha 4 Subunit Upregulation J Neurophysiol, January 1, 2003; 89(1): 186 - 198. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Xiang, J. R. Huguenard, and D. A. Prince Synaptic Inhibition of Pyramidal Cells Evoked by Different Interneuronal Subtypes in Layer V of Rat Visual Cortex J Neurophysiol, August 1, 2002; 88(2): 740 - 750. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Wang, M.-H. Kang-Park, W. A. Wilson, and S. D. Moore Properties of the Pathways From the Lateral Amygdal Nucleus to Basolateral Nucleus and Amygdalostriatal Transition Area J Neurophysiol, May 1, 2002; 87(5): 2593 - 2601. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Kim and B. E. Alger Random Response Fluctuations Lead to Spurious Paired-Pulse Facilitation J. Neurosci., December 15, 2001; 21(24): 9608 - 9618. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. E. Hasselmo and B. P. Fehlau Differences in Time Course of ACh and GABA Modulation of Excitatory Synaptic Potentials in Slices of Rat Hippocampus J Neurophysiol, October 1, 2001; 86(4): 1792 - 1802. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Savic and M. Sciancalepore Electrophysiological Characterization of "Giant" Cells in Stratum Radiatum of the CA3 Hippocampal Region J Neurophysiol, May 1, 2001; 85(5): 1998 - 2007. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. Kraushaar and P. Jonas Efficacy and Stability of Quantal GABA Release at a Hippocampal Interneuron-Principal Neuron Synapse J. Neurosci., August 1, 2000; 20(15): 5594 - 5607. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Dvorak-Carbone and E. M. Schuman Patterned Activity in Stratum Lacunosum Moleculare Inhibits CA1 Pyramidal Neuron Firing J Neurophysiol, December 1, 1999; 82(6): 3213 - 3222. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Bracci, M. Vreugdenhil, S. P. Hack, and J. G. R. Jefferys On the Synchronizing Mechanisms of Tetanically Induced Hippocampal Oscillations J. Neurosci., September 15, 1999; 19(18): 8104 - 8113. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Jensen, J. D. C. Lambert, and M. S. Jensen Activity-Dependent Depression of GABAergic IPSCs in Cultured Hippocampal Neurons J Neurophysiol, July 1, 1999; 82(1): 42 - 49. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. V. Buonomano and M. M. Merzenich Net Interaction Between Different Forms of Short-Term Synaptic Plasticity and Slow-IPSPs in the Hippocampus and Auditory Cortex J Neurophysiol, October 1, 1998; 80(4): 1765 - 1774. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. A. Boettiger and A. J. Doupe Intrinsic and Thalamic Excitatory Inputs Onto Songbird LMAN Neurons Differ in Their Pharmacological and Temporal Properties J Neurophysiol, May 1, 1998; 79(5): 2615 - 2628. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Caillard, H. A. McLean, Y. Ben-Ari, and J.-L. Gaiarsa Ontogenesis of Presynaptic GABAB Receptor-Mediated Inhibition in the CA3 Region of the Rat Hippocampus J Neurophysiol, March 1, 1998; 79(3): 1341 - 1348. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Wu and L. S. Leung Partial Hippocampal Kindling Decreases Efficacy of Presynaptic GABAB Autoreceptors in CA1 J. Neurosci., December 1, 1997; 17(23): 9261 - 9269. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Ouardouz and J.-C. Lacaille Properties of Unitary IPSCs in Hippocampal Pyramidal Cells Originating From Different Types of Interneurons in Young Rats J Neurophysiol, April 1, 1997; 77(4): 1939 - 1949. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Radnikow, J. Rohrbacher, and U. Misgeld Heterogeneity in Use-Dependent Depression of Inhibitory Postsynaptic Potentials in the Rat Neostriatum In Vitro J Neurophysiol, January 1, 1997; 77(1): 427 - 434. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Z. Haas, E. F. Sperber, S. L. Moshe, and P. K. Stanton Kainic Acid-Induced Seizures Enhance Dentate Gyrus Inhibition by Downregulation of GABAB Receptors J. Neurosci., July 1, 1996; 16(13): 4250 - 4260. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Chen and N. A. Lambert Endogenous regulators of G protein signaling proteins regulate presynaptic inhibition at rat hippocampal synapses PNAS, November 7, 2000; 97(23): 12810 - 12815. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |