Identification of GABA (Gamma-Amino-Butyric Acid) Receptor Binding Sites in Insect Ganglia

摘要

The binding of 3Hmuscimol to membrane fractions from central nervous tissue from fly (Musca domestica) and locust (Schistocerca gregaria) was measured. Specific saturable binding was observed with K sub ds of 10 nM (locust) and 40 nM (fly) and Bmax values of 20 fmol/mg protein (fly) and 60 fmol/mg protein (locust). Binding was Na(+)-independent and in locust tissue an additional Na(+)-dependent binding component was observed. Pharmacological properties of the binding sites in both species are consistent with a GABA receptor site rather than an uptake/transport site. We conclude that insect central nervous tissue contains receptors that show some similarities to the GABA receptor complex of mammalian brain.