Oscillations in the Insect Brain: Do they Correspond to the Cortical γ-Waves of Vertebrates?

γ-waves, relatively high-frequency oscillations (30-80 Hz) that can be recorded in the olfactory system and the visual cortex of vertebrates, have recently attracted much attention. A role as an information carrier is under discussion, a possible involvement in "feature linking" has been suggested, and they have also been implicated functionally in phenomena such as mind consciousness or awareness. It has long been known that stimulus-dependent high-frequency oscillations (hf waves) can also be recorded from the optic lobes of arthropods. These oscillations in flies have been examined and found to be analogous to the γ-waves in many respects. Based on knowledge of the anatomy and physiology of the visual system in flies, the most plausible interpretation of the function of these oscillations differs from the interpretations of the vertebrate γ-waves currently under consideration.