Octopamine enhances moth olfactory responses to pheromones, but not those to general odorants.

Effects of octopamine on responses of olfactory receptor neurons of Bombyx mori males and females, specialized to the reception of pheromone components and general odorants, respectively, were compared. Injections of octopamine had no effect on the transepithelial potential of antennal sensilla trichodea in both sexes. In males, octopamine increased significantly the amplitude of receptor potentials and nerve impulse responses elicited by the pheromone components bombykol and bombykal. However, the responses of homologous female general odorant-sensitive neurons to linalool and benzoic acid were not affected. In control experiments, injection of physiological saline did not increase the responses in any neuron type.