Experimental investigation of mechano-electrical signal transduction in a simple auditory organ [in the hearing organ of bushcrickets]
Final Report Abstract
Hearing organs open up the physical world of sound waves to us. Due to the structures of the respective hearing organ, different frequency bandwidth can be perceived. We have investigated how different ears of insects, especially bushcrickets, are adapted to their behavioural-relevant communication frequencies. We were able to detect a sex-specific auditory fovea in the ears of male Ancylecha fenestrata and showed how in the ears of Mecopoda elongata the vibration of the tympana and hearing organ (crista acustica) corresponds to the generated vocal frequencies. In addition, we demonstrated that sound waves in bushcricket ears cause slow waves, so-called travelling waves, whose properties are similar to those in the inner ear of mammals. These waves are distributed tonotopically and generate enough force to open transduction channels by a phase delay of the organ motion. A comparison of mechanical and neuronal tuning curves, measured at the same position of the crista acustica, revealed that mechano-sensitive ion channels only open when this phase delay along the longitudinal organ axis is present. A simple up and down movement (without phase delay) does not open the ion channels. This indicates that not all stimulus-induced motions are converted into neuronal responses and that intrinsic factors within the sensory cells, such as the position of the mechano-sensitive ion channels near the cap, play an important role in mechanoelectrical transduction process. Our investigations have clarified the function of the processes that describe the conversion of sound signals into a neuronal response in the sensory cells of the ear in living animals.
Publications
- 2010. Acoustic-induced motion of the bushcricket (Mecopoda elongata, Tettigoniidae) tympanum. J Comp Physiol A 196: 939-945
Nowotny M, Hummel J, Weber M, Möckel D, Kössl M
(See online at https://doi.org/10.1007/s00359-010-0577-6) - 2011. Sound Transduction in the Auditory System of Bushcrickets. In: Mechanics of Hearing. Shera C. and Olson E. (Eds.). World Scientific, Singapore, New Jersey, London, Hong Kong, pp. 461-465
Nowotny M.; Weber M.; Palghat Udayashankar A.; Hummel J.; Kössl M.
- 2011. Sound-induced tympanal membrane motion in bushcrickets and its relation to the sensory output. J Exp Biol. 214: 3596-3604
Hummel J, Kössl M, Nowotny M
(See online at https://doi.org/10.1242/jeb.054445) - 2011. Tonotopically ordered traveling waves in the hearing organs of bushcrickets in-vivo. In: Mechanics of Hearing. Shera C. and Olson E. (Eds.). World Scientific, Singapore, New Jersey, London, Hong Kong, pp. 466-472
Palghat Udayashankar A.; Kössl M.; Nowotny M.
(See online at https://doi.org/10.1063/1.3658132) - 2012. In-vivo measurements of tonotopically ordered traveling waves. PLoS One. 7(2): e31008
Palghat Udayashankar A, Kössl M, Nowotny M
(See online at https://doi.org/10.1371/journal.pone.0031008) - 2012. Temperature-dependence of DPOAEs in tympanal organs. J Exp Biol. 215:3309-3316
Möckel D, Lang J, Kössl M, Nowotny M
(See online at https://doi.org/10.1242/jeb.074377) - 2013. Mechanical tuning of the moth ear: distortion-product otoacoustic emissions and tympanal vibrations. J Exp Biol.216:3863-3872
Mora E C, Cobo-Cuan A, Macías F, Pérez M, Nowotny M, Kössl M
(See online at https://doi.org/10.1242/jeb.085902) - 2014. Mechanical basis of otoacoustic emissions in tympanal hearing organs. J Comp Physiol A. 200(7):681-691
Möckel D, Nowotny M, Kössl M
(See online at https://doi.org/10.1007/s00359-014-0914-2) - 2014. Neural processing in the bushcricket auditory pathway. In: Topics of Acoustic Communication in Insects. Hedwig B (Ed.) Springer-Verlag, Berlin, Heidelberg. Volume 1, 2014, pp 143-166
Stumpner A., Nowotny M.
(See online at https://doi.org/10.1007/978-3-642-40462-7_9) - 2014. Processing of simple and complex acoustic signals in a tonotopically organized ear. Proc Biol Sci. 281(1796): 20141872
Hummel J, Wolf K, Kössl M, Nowotny M
(See online at https://doi.org/10.1098/rspb.2014.1872) - 2014. Traveling wave energy is lateralized in the hearing organ of bushcrickets. Plos One 9(1): e86090
Palgath Udajashankar A, Kössl M, Nowotny M
(See online at https://doi.org/10.1371/journal.pone.0086090) - 2016. Auditory fovea in the ear of a duetting katydid shows male-specific adaptation to the female call. Curr Biol. 26(23):R1222-R1223
Scherberich J, Hummel J, Schöneich S, Nowotny M
(See online at https://doi.org/10.1016/j.cub.2016.10.035) - 2016. Gating of Acoustic Transducer Channels Is Shaped by Biomechanical Filter Processes. J Neurosci. 36(8):2377-2382
Hummel J, Schöneich S, Kössl M, Scherberich J, Hedwig B, Prinz S, Nowotny M
(See online at https://doi.org/10.1523/JNEUROSCI.3948-15.2016) - 2016. Mechanical and electrical tuning in a tonotopical organized ear. In: Mechanics of Hearing. Corey D.P. and Karavitaki K.D. (Eds.). World Scientific, Singapore, New Jersey, London, Hong Kong, AIP Conference Proceedings 1703, 100001
Hummel J, Schöneich S, Hedwig B, Nowotny M
(See online at https://doi.org/10.1063/1.4939429) - 2016. Mechanical investigations of sound-induced responses in a simple ear. In: Mechanics of Hearing. Corey D.P. and Karavitaki K.D. (Eds.). World Scientific, Singapore, New Jersey, London, Hong Kong. AIP Conference Proceedings 1703, 070008
Nowotny M., Hummel J., Kössl M., Palgath Udajashankar A
(See online at https://doi.org/10.1063/1.4939382) - 2017. Functional basis of the sexual dimorphism in the auditory fovea of the duetting bushcricket Ancylecha fenestrata. Proc Biol Sci. 284(1865)
Scherberich J, Hummel J, Schöneich S, Nowotny M
(See online at https://doi.org/10.1098/rspb.2017.1426) - 2017. Morphological basis for a tonotopic design of an insect ear. J Comp Neurol. 525(10):2443-2455
Hummel J, Kössl M, Nowotny M
(See online at https://doi.org/10.1002/cne.24218)
