Effects of neurotropic drugs on Drosophila melanogaster

Abstract

Drosophila melanogaster is sensitive to a variety of psychotropic and neurotropic drugs that alter neurotransmitter metabolism in humans. For many drugs the activity is a function of the stage of development of the organism. An example is the convulsant allylglycine (2-amino 4-pentenoic acid). Larvae were unaffected by a dose of allylglycine that was lethal for adults. Larvae that had been exposed to the drug continuously through three instars were able to pupate. In the pupae, which were no longer exposed to the drug, the pharate adults appeared to mature normally but subsequently died, usually before emerging from the puparium case. Allylglycine is known to inhibit mammalian glutamate decarboxylase. This enzyme is present in homogenates of Drosophila. Larvae possess a much smaller amount of glutamate decarboxylase than do adults. Allylglycine has a minimal effect on glutamate decarboxylase in vivo or in vitro. Several drug-resistant strains have been isolated.