Studies on l-glutamate in insect haemolymph.

ABSTRACT. The neuromuscular junctions of abdominal body wall muscles of larval Lucilia sericata are mainly superficial, with no glial sheath, and are surrounded by a well-developed subsynaptic reticulum. Injection of l -glutamate into the haemolymph of adult male Locusta migratoria and larvae of Lucilia sericata caused reversible effects on motor activity. These effects were quantified and dose—response curves are presented. The effective concentration of the injected doses is low enough to be physiologically relevant. Injection of l -aspartate into Locusta haemolymph affected motor activity. Injection of l -aspartate into Lucilia larvae produced no detectable effect. Injections combining l -aspartate and l -glutamate into Lucilia larvae had a synergistic effect on the duration of paralysis, compared with the same concentration of l -glutamate injected alone.