G proteins are involved in the regulation of transmitter release at an Aplysia cholinergic synapse

Brain Res. 1992 Mar 13;575(1):155-8. doi: 10.1016/0006-8993(92)90437-e.

Abstract

At an identified cholinergic synapse of the Aplysia buccal ganglion, presynaptic injections of guanosine 5'-O-3-thiotriphosphate (GTP-gamma-S) depressed the amplitude of evoked postsynaptic responses. This reduction of acetylcholine (ACh) release by GTP-gamma-S, prevented by pre-injection of guanosine 5'-O-2-thiodiphosphate (GDP-beta-S) in the presynaptic neuron, was due to a reduction of the number of ACh quanta released. The mean amplitude of the evoked miniature postsynaptic current (MPSC) was unchanged. The presynaptic Ca2+ influx was lowered.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / physiology*
  • Animals
  • Aplysia / metabolism*
  • Evoked Potentials / drug effects
  • GTP-Binding Proteins / physiology*
  • Guanosine 5'-O-(3-Thiotriphosphate) / pharmacology*
  • Iontophoresis
  • Neurotransmitter Agents / metabolism*
  • Synapses / metabolism*

Substances

  • Neurotransmitter Agents
  • Guanosine 5'-O-(3-Thiotriphosphate)
  • GTP-Binding Proteins
  • Acetylcholine