Block of GABA-transaminase modifies GABAergic transmission at the crayfish synapses Academic Article uri icon


  • 1. The cytosolic concentration of a neurotransmitter is believed to be an important factor determining its release. The effects of ethanolamine-O-sulfate (EOS), a gamma-aminobutyric acid (GABA)-transaminase blocker, on GABAergic postsynaptic and presynaptic inhibitory neurotransmission were examined in the crayfish opener neuromuscular synapses. 2. Intracellular recordings of evoked excitatory (EPSPs) and inhibitory postsynaptic potentials (IPSPs) as well as loose macropatch clamp measurements of excitatory (EPSCs) and inhibitory postsynaptic currents (IPSCs) were used to evaluate the effects of the drug, which was applied exclusively to the nerve bundle. 3. Under normal conditions, a stimulus train to the inhibitor before the excitor stimulation elicited two phases of inhibition: 1) a large reduction in EPSP amplitude associated with a decrease in its time constant of decay (tau D) at time intervals of 0–15 ms and 2) a moderate decrease in EPSP amplitude with a small change in EPSP tau D at intervals of ...

publication date

  • January 1, 1994