Functional characteristics of the interneurons of wind-sensitive hair-receptors on the head in Locusta migratoria L.—I. Interneurons with excitatory responses

Abstract 1. Excitatory responses of the interneurons of wind-sensitive hair receptors of the migratory locust have been analyzed using “wind-on-head” stimulation as well as microelectrode recordings from the connectives. It has been established that 2. 1. The excitatory responses of the interneurons may be slow or fast adapting as well as “on-off” types. 3. 2. The interneurons displaying a slowly adapting excitatory response may receive inhibition from the higher regions of the contralateral side (brain and subesophageal ganglion). 4. 3. The interneurons respond to stimulation of both sides, and the responses may be of identical or different types. 5. 4. The interneurons may be silent or possess a spontaneous activity. 6. 5. The neuronal pathways may run directly or cross over subesophageally in the first or second thoracic ganglia. The possibility is discussed that the response types of the interneurons are not a priori determined by their input connections, but the spontaneous activity and the types of responses are defined by functional factors in consequence of dynamic connections of the interneurons.