Octopaminergic Modulation of Locust Flight Muscle

Octopamine has been suggested to be a regulator of various aspects of insect flight. Its levels rise rapidly during the first few minutes of flight (Goosey and Candy, 1980) which may be related to its ability to regulate carbohydrate and lipid metabolism (Candy, 1978). In addition it may also function as a modulator of neuromuscular transmission in flight muscle (Klaassen, Kammer and Fitch, 1986) and of the central pattern generator for flight motor patterns (Sombati and Hoyle, 1984). However in the latter experiments it is not clear if octopamine has a specific direct action on the central pattern generator neurones or a more general effect due to an enhanced efficacy of sensory transmission producing an increase in arousal.