Interneuronal organization in the flight system of the locust

Abstract

In this paper we describe the characteristics, connections, resetting properties and organization of some identified interneurones in the flight system of the locust. The major conclusions are that: (1) the flight rhythm is generated at the interneuronal level and the flight oscillator is not continuously active (2) the interneurones in the flight pattern generator are distributed within at least 6 segmental ganglia (three thoracic and three fused abdominal ganglia) and are not organized into two homologous groups for the separate control of the forewing and the hindwing (3) this distribution of flight interneurones has no obvious functional significance but could be a consequence of flight having evolved from a segmentally distributed motor behaviour (4) there may be a functional hierarchy among flight interneurones such that premotor interneurones are separate from those generating the rhythm.