Avermectin B1a irreversibly blocks postsynaptic potentials at the lobster neuromuscular junction by reducing muscle membrane resistance.
Articolo
Data di Pubblicazione:
1979
Citazione:
Avermectin B1a irreversibly blocks postsynaptic potentials at the lobster
neuromuscular junction by reducing muscle membrane resistance / L.C. Fritz, C.C. Wang, A. Gorio. - In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. - ISSN 0027-8424. - 76:4(1979 Apr), pp. 2062-2066. [10.1073/pnas.76.4.2062]
Abstract:
Avermectin B1a, a macrocyclic lactone with broad spectrum anthelmintic activity,
affects neuromuscular transmission in the lobster stretcher muscle. Perfusion of
the muscle with 1-10 microgram of the drug per ml eliminates inhibitory
postsynaptic potentials within a few minutes. Intracellularly recorded excitatory
postsynaptic potentials are gradually reduced in amplitude over 20-30 min, and
their falling phases become faster; there is no effect, however, on
extracellularly recorded excitatory potentials. Avermectin B1a reduced the input
resistance of the muscle fibers with a time course similar to that of the
reduction of excitatory potentials. Washing for up to 2 hr with drug-free
solution fails to reverse the drug's effects. However, perfusion with 20
microgram of picrotoxin per ml results in recovery of the excitatory potentials
and input resistance. Avermectin B1a also blocks the firing of the crayfish
stretch receptor neuron, and this block is also reversed by picrotoxin. We
hypothesize that the reduction in excitatory postsynaptic potentials after
avermectin B1a treatment is caused solely by reduction in membrane resistance;
additional experiments suggest that the reduction in membrane resistance is due
to the opening of membrane Cl- channels, perhaps including those regulated by
gamma-aminobutyric acid at the inhibitory synapse.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
L.C. Fritz, C.C. Wang, A. Gorio
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