A study of the inhibitory action of γ-aminobutyric acid on neuromuscular transmission in the crayfish
- 1 March 1966
- journal article
- research article
- Published by Wiley in The Journal of Physiology
- Vol. 183 (2), 418-432
- https://doi.org/10.1113/jphysiol.1966.sp007874
Abstract
The effect of gamma-aminobutyric acid (GABA) on the neuromuscular junction of the crayfish (Cambarus clarkii) was investigated. The drug was applied iontophoretically to a junction and the potential changes were recorded intracellularly as well as extracellularly with micro-electrodes. The amplitude of the potential produced by iontophoretically applied L-glutamate was decreased by simultaneous application of GABA to the same junctional area. When the membrane potential was clamped at the resting level the clamping current for the L-glutamate injection was not changed by GABA application, indicating that there is no appreciable competition between L-glutamate and GABA for the glutamate-sensitive receptor. The excitatory nerve was stimulated repetitively and the excitatory junctional potentials (e.j.p.s) were recorded extracellularly with a microelectrode placed on the surface of the muscle. The average size of the extracellular e.j.p.s was reduced by the application of GABA. The number of quanta relased per impulse calculated from the extracellular e.j.p.s was decreased during the application of GABA, while the quantum size remained unchanged. The size of the excitatory presynaptic nerve spike was decreased by the application of GABA. However, no appreciable change was observed in the inhibitory nerve spike. These results indicate that in addition to its post-synaptic action GABA acts on the excitatory presynaptic nerve terminal and reduces the release of the transmitter.This publication has 22 references indexed in Scilit:
- On the permeability of the presynaptic terminal of the crayfish neuromuscular junction during synaptic inhibition and the action of γ‐aminobutyric acidThe Journal of Physiology, 1966
- Localized action of gamma‐aminobutyric acid on the crayfish muscleThe Journal of Physiology, 1965
- Potential changes in the crayfish motor nerve terminal during repetitive stimulationPflügers Archiv - European Journal of Physiology, 1965
- Presynaptic and postsynaptic effects of inhibitory drugs on the crayfish neuromuscular junctionPflügers Archiv - European Journal of Physiology, 1965
- The action of inhibitory drugs on nerve terminals in crayfish musclePflügers Archiv - European Journal of Physiology, 1965
- Presynaptic inhibition of the excitatory nerve terminal in the neuromuscular junction of the crayfishPflügers Archiv - European Journal of Physiology, 1963
- THE EXCITATION AND DEPRESSION OF SPINAL NEURONES BY STRUCTURALLY RELATED AMINO ACIDSJournal of Neurochemistry, 1960
- Membrane permeability change during inhibitory transmitter action in crustacean muscleThe Journal of Physiology, 1958
- The quantal components of the mammalian end‐plate potentialThe Journal of Physiology, 1956
- The effect of inhibitory nerve impulses on a crustacean muscle fibreThe Journal of Physiology, 1953