GABAergic inhibition of crayfish deep extensor abdominal muscle exhibits a steep dose-response relationship and a high degree of cooperativity

  title={GABAergic inhibition of crayfish deep extensor abdominal muscle exhibits a steep dose-response relationship and a high degree of cooperativity},
  author={Nicolas von Beckerath and Helmuth Adelsberger and Franz Parzefall and Ch. Franke and Josef Dudel},
  journal={Pfl{\"u}gers Archiv},
A patch-clamp study was done to characterize the recently found GABAergic (i.e. γ-aminobutyric acid) inhibitory synaptic channels of crayfish deep extensor abdominal muscle. Outside-out patches were rapidly activated by GABA to measure the dose/ response curves for the open probability of the channels, Po, and the rise time, tr, (time from Po=0.1 to Po=0.9). In some of the patches the GABA-activated currents decayed due to desensitization and such patches were not studied further. Rare channel… 
Characterization and molecular reaction scheme of a chloride channel expressed after axotomy in crayfish
The nerve to the deep extensor abdominal muscle in crayfish species Astacus astacus, containing four excitatory and one inhibitory motor axons, was cut in the third segment on one side of the animal and a detailed molecular scheme for the reaction of the channel with GABA was derived.
Neuromuscular glutamatergic and GABAergic channels
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A molecular scheme for the reaction between γ-aminobutyric acid and the most abundant chloride channel on crayfish deep extensor abdominal muscle
Simulations of the dose-responses and the open time distributions with this model led to a set of rate constants which generated relatively optimal fits, and indicated at least three open states.
Activation kinetics of Glutamate receptor channels from wild-type Drosophila muscle
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Innervation pattern of the deep extensor abdominal muscle in the crayfish species Astacus astacus
The deep extensor abdominal muscle consisting of one medial and two lateral muscle bundles together with the nerve innervating the muscles of crayfish species Astacus astacus, was prepared and the innervation pattern of the axons was determined.


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Four types of GABA receptors in crayfish leg muscles characterized by desensitization and specific antagonist
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Inhibitory synaptic channels activated by γ-aminobutyric acid (GABA) in crayfish muscle
Small crayfish muscle fibres were voltage clamped and synaptic current elicited by superfused GABA solutions was measured, finding that the current seems to be a synaptic one.
Acetylcholine activates a chloride channel as well as glutamate and GABA
SummaryIn conventional two microelectrode experiments, acetylcholine had qualitatively the same effect as GABA and glutamate on membrane potential and input resistance of muscle fibres of the opener
Single glutamate-gated synaptic channels at the crayfish neuromuscular junction
The most simple model of glutamate-receptor interaction contains two binding, sites for glutamate but no singly liganded open states and rate constants were estimated for this model.
cAMP increases the rate of GABAA receptor desensitization in chick cortical neurons
The results suggest that a cAMP‐dependent phosphorylation converts the GABA receptor into a more rapidly desensitizing form in the absence of exogenous GABA.
The excitatory glutamate-activated channel recorded in cell-attached and excised patches from the membranes of tail, leg and stomach muscles of crayfish
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