| Abstract: | Vast adaptability of insects is provided substantially by fast tining of physiological functioning of an organism to conform to the permanently changing environmental conditions. One of the mechanisms of plasticity in insects is modulation of performance of their sense organs by neurohormones. Activity of at least three out of four receptor cells located in cockroach pheromonesensitive sensilla is under influence of octopamine. Increase in firing rate of pheromone receptor cells and decrease in electroantennogram amplitude is accompanied by enhanced behavioural responses of male cockroaches to sex pheromone. The effect of octopamine on reception of a repellent (1,8-cineole) by an insect is reported for the first time. Simultaneous modulation of responses of receptor cells located in sex specific sensilla to semantically different odorants implies their cooperation in formation of insect's behaviour. |
