<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Arun Palghat Udayashankar</style></author><author><style face="normal" font="default" size="100%">Kössl, Manfred</style></author><author><style face="normal" font="default" size="100%">Nowotny, Manuela</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Lateralization of Travelling Wave Response in the Hearing Organ of Bushcrickets</style></title></titles><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://dx.plos.org/10.1371/journal.pone.0086090</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Travelling waves are the physical basis of frequency discrimination in many vertebrate and invertebrate taxa, including mammals, birds, and some insects. In bushcrickets (Tettigoniidae), the crista acustica is the hearing organ that has been shown to use sound-induced travelling waves. Up to now, data on mechanical characteristics of sound-induced travelling waves were only available along the longitudinal (proximal-distal) direction. In this study, we use laser Doppler vibrometry to investigate in-vivo radial (anterior-posterior) features of travelling waves in the tropical bushcricket Mecopoda elongata. Our results demonstrate that the maximum of sound-induced travelling wave amplitude response is always shifted towards the anterior part of the crista acustica. This lateralization of the travelling wave response induces a tilt in the motion of the crista acustica, which presumably optimizes sensory transduction by exerting a shear motion on the sensory cilia in this hearing organ.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Möckel, Doreen</style></author><author><style face="normal" font="default" size="100%">Nowotny, Manuela</style></author><author><style face="normal" font="default" size="100%">Kössl, Manfred</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Mechanical basis of otoacoustic emissions in tympanal hearing organs</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">DPOAE</style></keyword><keyword><style  face="normal" font="default" size="100%">Insect</style></keyword><keyword><style  face="normal" font="default" size="100%">laser Doppler vibrometry</style></keyword><keyword><style  face="normal" font="default" size="100%">locust</style></keyword><keyword><style  face="normal" font="default" size="100%">tympanum</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.springer.com/10.1007/s00359-014-0914-2</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Tympanal hearing organs of insects emit dis- tortion&amp;ndash;product otoacoustic emissions (DPOAes), which in mammals are used as indicator for nonlinear cochlear amplification, and which are highly vulnerable to manipu- lations interfering with the animal&amp;rsquo;s physiological state. Although in previous studies, evidence was provided for the involvement of auditory mechanoreceptors, the source of DPOAe generation and possible active mechanisms in tympanal organs remained unknown. Using laser Dop- pler vibrometry in the locust ear, we show that DPOAes mechanically emerge at the tympanum region where the auditory mechanoreceptors are attached. Those emission- coupled vibrations differed remarkably from tympanum waves evoked by external pure tones of the same frequency, in terms of wave propagation, energy distribution, and loca- tion of amplitude maxima. Selective inactivation of the auditory receptor cells by mechanical lesions did not affect the tympanum&amp;rsquo;s response to external pure tones, but abol- ished the emission&amp;rsquo;s displacement amplitude peak. These findings provide evidence that tympanal auditory recep- tors, comparable to the situation in mammals, comprise the required nonlinear response characteristics, which during two-tone stimulation lead to additional, highly localized deflections of the tympanum.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Arun Palghat Udayashankar</style></author><author><style face="normal" font="default" size="100%">Kössl, Manfred</style></author><author><style face="normal" font="default" size="100%">Nowotny, Manuela</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Tonotopically Arranged Traveling Waves in the Miniature Hearing Organ of Bushcrickets</style></title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://dx.plos.org/10.1371/journal.pone.0031008</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Place based frequency discrimination (tonotopy) is a fundamental property of the coiled mammalian cochlea. Sound vibrations mechanically conducted to the hearing organ manifest themselves into slow moving waves that travel along the length of the organ, also referred to as traveling waves. These traveling waves form the basis of the tonotopic frequency representation in the inner ear of mammals. However, so far, due to the secure housing of the inner ear, these waves only could be measured partially over small accessible regions of the inner ear in a living animal. Here, we demonstrate the existence of tonotopically ordered traveling waves covering most of the length of a miniature hearing organ in the leg of bushcrickets in vivo using laser Doppler vibrometery. The organ is only 1 mm long and its geometry allowed us to investigate almost the entire length with a wide range of stimuli (6 to 60 kHz). The tonotopic location of the traveling wave peak was exponentially related to stimulus frequency. The traveling wave propagated along the hearing organ from the distal (high frequency) to the proximal (low frequency) part of the leg, which is opposite to the propagation direction of incoming sound waves. In addition, we observed a non-linear compression of the velocity response to varying sound pressure levels. The waves are based on the delicate micromechanics of cellular structures different to those of mammals. Hence place based frequency discrimination by traveling waves is a physical phenomenon that presumably evolved in mammals and bushcrickets independently.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Nowotny, Manuela</style></author><author><style face="normal" font="default" size="100%">Arun Palghat Udayashankar</style></author><author><style face="normal" font="default" size="100%">Weber, Melanie</style></author><author><style face="normal" font="default" size="100%">Hummel, Jennifer</style></author><author><style face="normal" font="default" size="100%">Kössl, Manfred</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Sound Transduction in the Auditory System of Bushcrickets</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">LDV-measurements</style></keyword><keyword><style  face="normal" font="default" size="100%">tonotopy</style></keyword><keyword><style  face="normal" font="default" size="100%">traveling wave</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://aip.scitation.org/doi/abs/10.1063/1.3658131</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Place based frequency representation, called tonotopy,is a typical property of hearing organs for the discrimination of different frequencies. Due to its coiled structure and secure housing, it is difficult access the mammalian cochlea. Hence, our knowledge about in vivo inner-ear mechanics is restricted to small regions. In this study, we present in vivo measurements that focus on the easily accessible, uncoiled auditory organs in bushcrickets, which are located in their foreleg tibiae. Sound enters the body via an opening at the lateral side of the thorax and passes through a horn-shaped acoustic trachea before reaching the high frequency hearing organ called crista acustica. In addition to the acoustic trachea as structure that transmits incoming sound towards the hearing organ, bushcrickets also possess two tympana, specialized plate-like structures, on the anterior and posterior side of each tibia. They provide a secondary path of excitation for the sensory receptors at low frequencies. We investigated the mechanics of the crista acustica in the tropical bushcricket Mecopoda elongata. The frequency-dependent motion of the crista acustica was captured using a laser-Doppler-vibrometer system. Using pure tone stimulation of the crista acustica, we could elicit traveling waves along the length of the hearing organ that move from the distal high frequency to the proximal low frequency region. In addition, distinct maxima in the velocity response of the crista acustica could be measured at ̃7 and ̃17 kHz. The travelling-wave-based tonotopy provides the basis for mechanical frequency discrimination along the crista acustica and opens up new possibility to investigate traveling wave mechanics in vivo.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Nowotny, Manuela</style></author><author><style face="normal" font="default" size="100%">Hummel, Jennifer</style></author><author><style face="normal" font="default" size="100%">Weber, Melanie</style></author><author><style face="normal" font="default" size="100%">Möckel, Doreen</style></author><author><style face="normal" font="default" size="100%">Kössl, Manfred</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Acoustic-induced motion of the bushcricket (Mecopoda elongata, Tettigoniidae) tympanum</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acoustic resonance</style></keyword><keyword><style  face="normal" font="default" size="100%">insect hearing</style></keyword><keyword><style  face="normal" font="default" size="100%">trachea</style></keyword><keyword><style  face="normal" font="default" size="100%">Vibration measurements</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.springer.com/10.1007/s00359-010-0577-6</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hummel, Jennifer</style></author><author><style face="normal" font="default" size="100%">Wolf, Konstantin</style></author><author><style face="normal" font="default" size="100%">Kössl, Manfred</style></author><author><style face="normal" font="default" size="100%">Nowotny, Manuela</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Processing of simple and complex acoustic signals in a tonotopically organized ear</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">bushcricket</style></keyword><keyword><style  face="normal" font="default" size="100%">crista acustica</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrophysiology</style></keyword><keyword><style  face="normal" font="default" size="100%">insect hearing</style></keyword><keyword><style  face="normal" font="default" size="100%">laser Doppler vibrometry</style></keyword><keyword><style  face="normal" font="default" size="100%">Tettigoniidae</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://royalsocietypublishing.org/doi/10.1098/rspb.2014.1872https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2014.1872</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Processing of complex signals in the hearing organ remains poorly understood. This paper aims to contribute to this topic by presenting investigations on the mechanical and neuronal response of the hearing organ of the tropical bushcricket species Mecopoda elongata to simple pure tone signals as well as to the conspecific song as a complex acoustic signal. The high-frequency hearing organ of bushcrickets, the crista acustica (CA), is tonotopically tuned to frequencies between about 4 and 70 kHz. Laser Doppler vibrometer measurements revealed a strong and dominant low-frequency-induced motion of the CA when stimulated with either pure tone or complex stimuli. Consequently, the high-frequency distal area of the CA is more strongly deflected by low-frequency-induced waves than by high-frequency-induced waves. This low-frequency dominance will have strong effects on the processing of complex signals. Therefore, we additionally studied the neuronal response of the CA to native and frequency-manipulated chirps. Again, we found a dominant influence of low-frequency components within the conspecific song, indicating that the mechanical vibration pattern highly determines the neuronal response of the sensory cells. Thus, we conclude that the encoding of communication signals is modulated by ear mechanics.&lt;/p&gt;
</style></abstract></record></records></xml>