Document Detail


Presynaptic inhibition of miniature excitatory synaptic currents by baclofen and adenosine in the hippocampus.
MedLine Citation:
PMID:  1358131     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Presynaptic inhibition of neurotransmitter release is thought to be mediated by a reduction of axon terminal Ca2+ current. We have compared the actions of several known inhibitors of evoked glutamate release with the actions of the Ca2+ channel antagonist Cd2+ on action potential-independent synaptic currents recorded from CA3 neurons in hippocampal slice cultures. Baclofen and adenosine decreased the frequency of miniature excitatory postsynaptic currents (mEPSCs) without affecting the distribution of their amplitudes. Cd2+ blocked evoked synaptic transmission, but had no effect on the frequency or amplitude of either mEPSCs or inhibitory postsynaptic currents (IPSCs). Inhibition of presynaptic Ca2+ current therefore appears not to be required for the inhibition of glutamate release by adenosine and baclofen. Baclofen had no effect on the frequency of miniature IPSCs, indicating that gamma-aminobutyric acid B-type receptors exert distinct presynaptic actions at excitatory and inhibitory synapses.
Authors:
M Scanziani; M Capogna; B H Gähwiler; S M Thompson
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Neuron     Volume:  9     ISSN:  0896-6273     ISO Abbreviation:  Neuron     Publication Date:  1992 Nov 
Date Detail:
Created Date:  1992-12-17     Completed Date:  1992-12-17     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8809320     Medline TA:  Neuron     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  919-27     Citation Subset:  IM    
Affiliation:
Brain Research Institute, University of Zurich, Switzerland.
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MeSH Terms
Descriptor/Qualifier:
2-Amino-5-phosphonovalerate / pharmacology
6-Cyano-7-nitroquinoxaline-2,3-dione
Action Potentials
Adenosine / pharmacology*
Animals
Baclofen / pharmacology*
Bicuculline / pharmacology
Cadmium / pharmacology
Calcium / metabolism
Electric Conductivity
Glutamates / antagonists & inhibitors,  secretion
Glutamic Acid
Hippocampus / drug effects,  physiology*
Quinoxalines / pharmacology
Rats
Receptors, GABA-A / antagonists & inhibitors,  physiology
Synapses / drug effects*,  physiology*
Tetrodotoxin / pharmacology
Chemical
Reg. No./Substance:
0/Glutamates; 0/Quinoxalines; 0/Receptors, GABA-A; 1134-47-0/Baclofen; 115066-14-3/6-Cyano-7-nitroquinoxaline-2,3-dione; 4368-28-9/Tetrodotoxin; 485-49-4/Bicuculline; 56-86-0/Glutamic Acid; 58-61-7/Adenosine; 7440-43-9/Cadmium; 7440-70-2/Calcium; 76726-92-6/2-Amino-5-phosphonovalerate

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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