Multisegmental Integration and Divergence of Afferent Information from Single Tactile Hairs in a Cricket

Abstract

The long tactile hairs of crickets contribute to intersegmental receptive fields of interneurones that integrate input from different types of tactile mechano-sensory hairs. Afferent input from the identified long hairs studied converges on a group of multisegmental interneurones of the abdominal and thoracic ganglia. Conversely, the input from each tactile hair receptor diverges to several multisegmental interneurones and also to motoneurones of their own and neighbouring segments. The interneurones have spike initiating zones in each ganglion they reach. Spikes initiated by hair afferents can travel caudally and rostrally in an interneurone. These interneurones spreading tactile information from single sensory cells to several ganglia are not suited for fine discrimination of sources of touch which could elicit specific somatotopically oriented motor behaviour of the cricket. More specific pathways from long tactile hairs to motoneurones exist in abdominal and thoracic segments.