Document Detail


Spontaneous excitatory postsynaptic currents in crayfish neuromuscular junctions in the absence and presence of serotonin and 3,4-diaminopyridine.
MedLine Citation:
PMID:  3746725     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Spontaneous excitatory postsynaptic currents (sEPSCs) were recorded under voltage clamp in short fibres (l less than or equal to 0.6 mm) from opener muscles and the contractor epimeralis muscle of small crayfish. From the amplitude distributions of sEPSCs which could be approximated by a Gaussian function, a mean amplitude ã = -1.16 nA +/- 0.28 (SE) was found for sEPSCs in 16 fibres of the claw opener voltage clamped to E = -60 mV (19-22 degrees C). In the opener of the first walking leg and in the contractor epimeralis muscle ã = -1.1 nA +/- 0.21 (SE; n = 6, -100 mV less than or equal to E less than or equal to -60 mV, 5-10 degrees C) and ã = -2.0 nA +/- 0.2 (SE; n = 4, E = -60 mV, 19-22 degrees C) were obtained. On average about 300-500 synaptic channels were estimated to open during a sEPSC. 'Giant' sEPSCs (gsEPSCs) were also observed. The amplitudes of gsEPSCs were up to 14 times larger than the amplitude of an average normal sEPSC. Moreover, the lifetime of gsEPSCs was up to about 3 times longer than that of sEPSCs. Like sEPSCs, gsEPSCs could not be abolished by 0.1 mumol/l tetrodotoxin. The rate at which sEPSCs and gsEPSCs occurred could be markedly enhanced by serotonin (1 mumol/l) and 3,4-diaminopyridine (1 mmol/l).
Authors:
W Finger; C Martin
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of comparative physiology. A, Sensory, neural, and behavioral physiology     Volume:  159     ISSN:  0340-7594     ISO Abbreviation:  J. Comp. Physiol. A     Publication Date:  1986 Jul 
Date Detail:
Created Date:  1986-10-23     Completed Date:  1986-10-23     Revised Date:  2009-06-04    
Medline Journal Info:
Nlm Unique ID:  8413199     Medline TA:  J Comp Physiol A     Country:  GERMANY, WEST    
Other Details:
Languages:  eng     Pagination:  13-20     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
4-Aminopyridine* / analogs & derivatives*
Aminopyridines / pharmacology*
Astacoidea
Electric Stimulation
Evoked Potentials / drug effects
Neuromuscular Junction / drug effects,  physiology*
Serotonin / pharmacology*
Synapses / drug effects,  physiology*
Chemical
Reg. No./Substance:
0/Aminopyridines; 50-67-9/Serotonin; 504-24-5/4-Aminopyridine; 54-96-6/3,4-diaminopyridine

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


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