PHYSIOLOGY AND CENTRAL PROJECTION OF AUDITORY RECEPTOR-CELLS IN THE PROTHORACIC GANGLION OF 3 CLOSELY RELATED SPECIES OF BUSH-CRICKETS (TETTIGONIIDAE, INSECTA)

A comparative study was made of the projection patterns of functionall y and morphologically identified auditory receptor cells of the comple x tibial organ in the forelegs of three closely related Decticine spec ies. A combined recording and staining technique was used, with subseq uent histological examination and morphometric measurements. Adult mal es and females of the species Psorodonotus illyricus, Decticus albifro ns, and Decticus verrucivorus, were chosen for this investigation. No species-specific differences were found in the projection patterns of receptor cells that belonged to the same or similar functional classes in the three species. The cells also occupied the same target areas w ithin the neuropile. A significant overlapping of the projections of t he different receptor cells within the neuropile of the anterior ring tract (aRT) was revealed, in particular of those cells that were tuned to characteristic frequencies within similar frequency bands.