Influence of glutamate and aspartate on time course of decay of excitatory synaptic currents at locust neuromuscular junctions.

The influence of glutamate and aspartate on the time course of decay of excitatory currents at neuromuscular junctions of locust skeletal muscle was examined. Both aspartate (up to 10 mM) and glutamate (up to 0.3 mM) had little influence on the decay time of the synaptic currents, whether measured intracellularly by voltage-clamp or extracellularly with a focal electrode. These results do not exclude a role for an active uptake system in sequestering neurally released transmitter at locust neuromuscular junctions, but they suggest that it has a negligible influence on the time course of the synaptic currents.