Flight Activity Initiated via Giant Interneurons of the Cockroach: Evidence for Bifunctional Trigger Interneurons.

Activity in dorsal giant interneurons of the cockroach initiates flight movements if leg contact with a substrate is prevented. The same interneurons initiate activity associated with running when leg contact is maintained. Thus, which one of two completely different behaviors the giant interneurons evoke depends on the presence or absence of leg contact.