CONTENTS 6
Preface 14
Acknowledgments 16
Workshop Photograph 17
Workshop Delegates 20
SECTION I SOUND TRANSMISSION TO AND FROM THE INNER EAR, AND WAVE PROPAGATION WITHIN IT 30
Time average holography study of human tympanic membrane with altered middle ear ossicular chain J.T. Cheng, M.E. Ravicz, J.J. Rosowski, N. Hulli, M.S. Hernandez-Montes and C. Furlong 32
1 Introduction 32
2 Method 33
2.1 Time Average Holographic Interferometry (TAHI) 33
2.2 Temporal Bone Preparation 33
2.3 Holographic Interferometry Measurement 33
2.4 Laser Doppler Vibrometry (LDV) Measurement of stapes motion 34
2.5 Ossicular Chain Fixation 34
2.6 Analysis of TAHI Images for TM Sensitivity to Sound 34
3 Results and Discussion 35
4 Conclusion 37
Acknowledgments 37
References 37
Measurements of middle ear pressure gain and cochlear input impedance in the chinchilla M.C.C. Slama, M.E. Ravicz, H.H. Nakajima, W. Dong and J.J. Rosowski 38
1 Introduction 38
2 Methods 39
2.1 Animal Preparation 39
2.2 Fiber-Optic Pressure Sensors 39
2.3 Laser Doppler Vibrometry 40
2.4 Pressure Near the Tympanic Membrane 40
3 Results 40
3.1 Middle Ear Pressure Gain 40
3.2 Normalized Stapes Velocity 41
3.3 Cochlear Input Impedance 41
4 Discussion 41
4.1 High Frequency Responses 41
4.2 Effect of the Vestibular Hole 42
4.3 Comparison with other Chinchilla Studies 42
Acknowledgments 43
References 43
A middle-ear reverse transfer function computed from vibration measurements of otoacoustic emissions on the ear drum of the guinea pig E. Dalhoff, D. Turcanu and A.W. Gummer 44
1 Introduction 44
2 Methods 44
3 Results 45
4 Discussion 46
Acknowledgments 47
References 47
Differential intracochlear sound pressure measurements in normal human temporal bones H.H. Nakajima, W. Dong, E.S. Olson, S.N. Merchant, M.E. Ravicz and J.J. Rosowski 48
1 Introduction 48
2 Methods 49
3 Results and Discussion 50
3.1 Transfer Functions of Intracochlear Pressures 50
3.2 Pressure Gain of the Middle Ear 50
3.3 Differential Pressure 51
3.4 Effect of Ossicular Discontinuity on Sound Transmission 51
3.5 Cochlear Input Impedance (ZC) 52
Acknowledgments 53
References 53
Comparing otoacoustic emissions and basilar membrane motion in individual ears N.P. Cooper and C.A. Shera 54
1 Summary 54
Acknowledgments 55
References 55
The role of compression and traveling wave pressures in the transmission of sound out of the gerbil cochlea W. Dong and E.S. Olson 56
1 Introduction 56
2 Methods 57
3 Results 57
3.1 Traveling-wave is dominant at frequencies around the BF 58
3.2 Compression pressure is apparent at frequencies well above the cutoff frequency 58
3.3 Transmission of DPs inside the cochlea 59
4 Discussion 60
Acknowledgments 61
References 62
Comments & Discussion 62
Obvious and \u2018hidden\u2019 waves in the cochlea E. de Boer and A.L. Nuttall 63
1 Introduction \u2013 \u2018hidden waves\u2019 63
2 Classical and non-classical models 64
3 An example: Distortion-Product (DP) waves in a feed-forward model 65
Acknowledgments 67
References 67
Comments & Discussion 68
DP phases in mammalian cochleae, predicted from liquid-surface-wave formulas R. Frosch 70
1 Introduction 70
2 Methods 70
2.1 Surface-Wave Formulas 70
2.2 Cochlear Parameters for Gerbil 71
2.3 Validity of the Short-Wave Approximation 72
2.4 Locations of DP Generation 72
3 Results 73
4 Discussion 75
Acknowledgments 75
References 75
Comments and Discussion 76
Distortion product emissions: Where do they come from? X. Zhang and D.C. Mountain 77
1 Introduction 77
2 Methods 78
2.1 The classical one dimension nonlinear model 78
2.2 DPOAE responses of the nonlinear cochlea model 78
3 Results 79
3.1 Comparison to experimental data 79
3.2 Distortion product origins 80
4 Discussion 81
Acknowledgments 82
References 82
Comments and Discussion 83
Retrograde propagation of cochlear distortion S.T. Neely and Y.-W. Liu 84
1 Introduction \u2013 The Allen-Fahey Experiment 84
2 Cochlear Model 85
2.1 Macro-mechanics 85
2.2 Micro-mechanics 85
2.3 Outer hair cell 86
2.4 Propagation function 87
3 Model Results 87
4 Discussion 89
Acknowledgments 89
References 89
Comments and Discussion 90
Retrograde waves in the cochlea S.T. Neely and J.B. Allen 91
1. Introduction 91
2. Cochlear model 91
3. Wave variables 92
4. Approximate wave variables 94
5. Discussion 95
6. Conclusions 96
Acknowledgments 96
References 96
Comments and Discussion 96
Cochlear reflectivity and teoae transfer function R. Sisto, A. Moleti and F. Sanjust 97
1 Introduction 97
2 Model 98
3 Methods 100
4 Results and Discussion 101
5 Conclusions 102
References 102
Time domain model of a nonlinear inhomogeneous cochlea S.J. Elliott, E.M. Ku and B. Lineton 103
1 Introduction 103
2 Formulation of the State Space Model 103
3 The Effect of Inhomogeneities in the Linear Cochlea 105
4 Instabilities in the Nonlinear Inhomogeneous Cochlea 106
5 Conclusions 108
References 109
Comments and Discussion 109
Periodicity in the spectrum of modelled spontaneous otoacoustic emissions E.M. Ku, S.J. Elliott and B. Lineton 111
1 Summary 111
Acknowledgments 112
References 112
Modeling stimulus-frequency otoacoustic emissions in the gecko C. Bergevin and C.A. Shera 114
1. Introduction 114
2. The Model 114
3. Analytic Approximation for the Delay 116
4. Comparison with Experiment 117
5. Summary 118
Acknowledgments 119
References 119
SECTION II COCHLEAR AMPLIFICATION: CHARACTERISTICS, MODULATION AND CONTROL 120
Nonlinear cochlear signal processing and phoneme perception J.B. Allen, M. R茅gnier, S. Phatak and F. Li 122
1. Introduction 122
2. Key studies 123
2.1. Identifying events 125
2.1.1. Speech-Plosive events 125
2.1.2. Fricative sounds 128
2.2. Verification methods 128
3. Nonlinear cochlear speech processing 129
3.1. Function of the Inner Ear in speech perception 129
3.2. The dynamic range problem 130
Summary 131
Acknowledgments 132
References 132
Comments and Discussion 134
Determining the identity of the cochlear amplifier: Electrical stimulation of the Tecta mouse cochlea M.M. Mellado Lagarde, M. Drexl, V.A. Lukashkina, A.N. Lukashkin and I.J. Russell 135
1 Introduction 135
2 Methods 136
3 Results 137
4 Discussion 139
Acknowledgments 139
References 139
Comments and Discussion 141
Differential measurement of basilar membrane vibration in sensitive gerbil cochleae T. Ren and W. He 142
1 Introduction 142
2 Materials and Methods 143
2.1 Animals and surgical procedures 143
2.2 Measurement of conventional basilar membrane transfer functions 143
2.3 Measurement of local basilar membrane transfer functions 143
3 Results 144
3.1 Conventional basilar membrane transfer functions 144
3.2 Local basilar membrane transfer functions 145
3.3 Comparison of conventional and local basilar membrane transfer functions 146
4 Discussion 146
Acknowledgments 147
References 147
Comments and Discussion 148
Amplification in the cochlear apex A. Fridberger and S. Jacob 151
1 Introduction 151
1.1 Amplification in the apex 151
2 Methods 151
2.1 Interferometry 152
2.2 Resampled confocal imaging 152
2.3 Current injection and recording of cochlear microphonics 152
3 Results 152
3.1 Interferometry 152
3.2 Resampled confocal microscopy 153
4 Discussion 153
Acknowledgments 154
References 154
Comments and Discussion 154
Quantifying the passive substrate for active cochlear tuning E.S. Olson, O. de la Rochefoucauld and W. Dong 157
1 Introduction 157
1.1 Background to MOCC + local resonance 158
1.2 Background to resistive (real ) and reactive (imaginary) parts of ZOCC 158
2 Methods 159
3 Results 160
3.1 MOCC and SOCC found with BM velocity measurements + model 160
3.2 Direct measurements of resistive and reactive components of ZOCC 161
4 Discussion 162
Acknowledgments 162
References 162
Comments and Discussion 163
Organ of corti micromechanics with local electrical stimulation F. Chen, J. Zheng, N. Choudhury, S. Jaques and A.L. Nuttall 164
1 Introduction 164
2 Methods 165
2.1 OCT 165
2.2 Animal preparation 165
3 Results 165
3.1 OCT images 165
3.2 BM responses at 3 longitudinal positions under RW stimulation 166
3.3 BM and RL phase difference under electrical stimulation 167
4 Discussion 167
Acknowledgments 168
References 168
Comments and Discussion 169
Does the cochlea compromise on sensitivity and frequency selectivity? A.N. Lukashkin, V.A. Lukashkina, G.P. Richardson and I.J. Russell 170
1 Introduction 170
2 Methods 170
3 Results 171
3.1 BM tuning is sharper in Tectb-/- mice 171
3.2 Neural masking tuning is sharper in Tectb-/- mice 173
4 Discussion 174
5 Conclusion 175
Acknowledgments 175
References 175
Comments and Discussion 176
Novel roles for prestin in frequency tuning and neural excitation in the mouse cochlea M.M. Mellado Lagarde, M. Drexl, A.N. Lukashkin, J. Zuo and I.J. Russell 177
1 Introduction 177
2 Materials and Methods 178
3 Results 178
4 Discussion 181
Acknowledgments 182
References 182
Comments and Discussion 183
Bias-tone effects on the first-peak versus later peaks of auditory-nerve responses J. J. Guinan Jr. 184
1 Introduction 184
2 Methods 185
3 Results 185
4 Discussion 187
Acknowledgments 189
References 189
Comments and Discussion 190
Dual tuning in the mammalian cochlea: Dissociation of neural and basilar membrane responses at supra-threshold sound levels \u2013 A meta-analysis M. Braun 191
1 Introduction 191
2 Methods 191
3 Results 192
3.1 Basilar membrane 192
3.2 Auditory nerve fibers 192
3.3 Comparison BM versus ANF 193
3.4 Stability of BF of ANF responses in cross-correlation data 193
3.5 Level independence of BF in further neural pathway 193
4 Discussion 194
4.1 Dual tuning 194
4.2 Function of dual tuning 194
5 Conclusions 195
6 Addendum 195
References 195
Slow oscillatory cochlear adaptation to brief over stimulation: Cochlear homeostasis dynamics D.T. Kemp and O.J. Brill 197
1 Introduction 197
1.1 Rationale of this study 198
2 Method 198
3 Results 199
4 Model 199
5 Conclusion 202
Acknowledgments 202
References 202
Adaptive behaviour shown in ear-canal pressures related to distortion product magnitudes E.L. LePage and N.M. Murray 204
1 Introduction 204
1.1 Previous evidence supporting the notion of homeostatic regulation 204
1.2 Working hypothesis 205
2 Methods 205
3 Results 206
4 Discussion 208
5 Conclusions 209
Acknowledgments 209
References 209
The influence of language experience on contralateral suppression of click-evoked otoacoustic emissions in young adults S.P. Bhagat and J. Xu 210
1 Summary 210
Acknowledgments 211
References 211
Amplitude and frequency modulations of spontaneous otoacoustic emissions L. Bian 212
1 Introduction 212
2 Methods 213
2.1 Bias Tones 213
2.2 Signal Processing and Data Analysis 213
3 Results 213
3.1 Spectral Fine-Structures 213
3.2 Quasi-static Modulation Patterns 214
3.3 Period Modulation Patterns 215
4 Discussion 216
Acknowledgments 217
References 217
Comments and Discussion 218
Shifting the operating point of cochlear amplification? Impact of low frequency biasing and contralateral sound stimulation on DPOAE A. Wittekindt, C. Abel and M. K枚ssl 219
1 Introduction 219
2 Methods 220
3 Results 220
3.1 Basic effects of contralateral noise on f2-f1 and 2f1-f2 220
3.2 Low frequency biasing induced DPOAE modulation \u2013 effect of CAS 221
4 Discussion 223
Acknowledgments 224
References 224
The effect of ear canal pressure on spontaneous otoacoustic emissions: Comparison between human and lizard ears P. van Dijk and G.A. Manley 225
1. Introduction 225
2. Material and Methods 226
3. Results 226
4. Discussion 228
References 230
Comments and Discussion 231
Dependence of distortion-product otoacoustic emission components on primary-level ratio G.R. Long, C. Jeung and C.L. Talmadge 232
1 Introduction 232
1.1 Extracting Distortion Product Otoacoustic Emissions (DPOAE) components 232
1.2 Choosing the Primary Levels 233
2 Methods 233
3 Results 234
3.1 Changes in Fine-Structure Frequency with Level 234
3.2 I/O for the Two Major Components as a Function of Primary Ratio 234
4 Discussion 236
Acknowledgments 237
References 237
Otoacoustic emissions evoked by two-tone bursts using linear and non-linear protocol W.W. Jedrzejczak, J. Smurzynski, K.J Blinowska, K. Kochanek and H. Skarzynski 238
1 Introduction 238
2 Materials and method 239
2.1 Instrumentation and stimuli 239
2.2 Method of data analysis 239
3 Results 240
4 Conclusions 243
Acknowledgment 243
References 243
SECTION III NEW MEASUREMENT TECHNIQUES 244
Distortion product otoacoustic emissions evoked by tone complexes S.W.F. Meenderink and M. van der Heijden 246
1 Introduction 246
2 Methods 246
3 Results 247
3.1 The far group 248
3.2 The near group 248
3.3 The suppression group 249
3.4 Model attempt 250
4 Discussion 251
Acknowledgments 251
References 251
Removal of the DPOAE second generation source with a pulsed paradigm method improves hearing threshold estimation in humans D. Turcanu, A. Vetesnik, E. Dalhoff and A.W. Gummer 252
1 Summary 252
Acknowledgments 253
References 253
Hard X-rays can be used to visualize cochlear soft tissue displacements in a closed cochlea C.-P. Richter, A. Fishman, L. Fan., S. Shintani and C. Rau 254
1 Introduction 254
2 Methods 255
2.1 The radiation source 255
2.2 Data acquisition 255
2.3 Optical flow analysis 256
3 Results 256
4 Discussion 257
Acknowledgments 257
References 257
SECTION IV MICROMECHANICS: BM, TM AND SUB-TECTORIAL SPACE 260
Frequency-selective response of the tectorial membrane in the frog basilar papilla R.L.M. Schoffelen, J.M. Segenhout and P. van Dijk 262
1. Introduction 262
2. Methods 262
3. Results 265
4. Discussion 266
Acknowledgments 267
References 267
Comments and Discussion 268
Mechanical response of the basilar membrane to lateral micromanipulation S.O. Newburg, A. Zosuls, P.E. Barbone and D.C. Mountain 269
1. Introduction 269
2. Methods 270
3. Results 270
4. Discussion 273
Acknowledgments 274
References 274
Comments and Discussion 275
Traveling waves... on the tectorial membrane R. Ghaffari, A.J. Aranyosi and D.M. Freeman 276
1. Introduction 276
2. Methods 276
3. Measurements and Model 278
4. Discussion 280
Acknowledgments 281
References 281
Comments and Discussion 281
The anisotropy of the tectorial membrane guides stereocilia deflection R. Gueta, D. Barlam, R.Z. Shneck and I. Rousso 284
1 Introduction 284
2 Results and Discussion 285
Acknowledgments 288
References 289
Comments and Discussion 289
Tectorial membrane traveling waves: A new mechanism for longitudinal coupling A.J. Aranyosi, R. Ghaffari and D.M. Freeman 291
1. Introduction \u2013 The TM supports traveling waves 291
1.1. A closed-form approximation for TM waves 291
2. Driving TM waves with a cochlear model 292
3. Results 293
3.1. TM responses are inconsistent with classical models 293
3.2. Effect of wave parameters on TM tuning 294
4. Discussion 295
4.1. Bidirectional TM traveling waves 295
4.2. The effect of model parameters 295
4.3. Implications for cochlear tuning 295
Acknowledgments 296
References 296
Comments and Discussion 296
Modeling Hensen\u2019s stripe as a topographic waveguide that defines the roles of the OHC and IHC J.T. Fulton 298
1 Introduction 298
2 The operation of the vestibule of the labyrinth and the cochlear partition 298
3 The mathematical description and performance of the cochlear partition 300
4 Conclusion 304
References 304
Measurement of anisotropic mechanical properties of the tectorial membrane N. Gavara and R.S. Chadwick 305
1 Introduction 305
2 Methods 306
2.1 Sample isolation 306
2.2 Setup 306
2.3 Protocol 307
2.4 Data processing 307
2.5 Modelling 308
3 Results 308
4 Discussion 309
Acknowledgments 310
References 310
Comments and Discussion 311
Deflection of IHC stereocilia in response to somatic OHC electromotility C. Chiaradia, M. Nowotny and A.W. Gummer 312
1 Introduction 312
2 Methods 312
3 Results 314
4 Discussion Amplitude [dB] 315
Acknowledgments 316
References 316
Comments and Discussion 316
Fluid mechanics in the subtectorial space J. Baumgart, C. Chiaradia, M. Fleischer, Y. Yarin, R. Grundmann and A.W. Gummer 317
1. Introduction 317
2. Methods 318
2.1. Fluid-Structure-Interaction 318
2.2. Geometry 319
2.3. Properties 319
3. Results 320
4. Discussion 321
Acknowledgments 321
References 322
SECTION V MODELLING THE COCHLEAR AMPLIFIER AND THE COCHLEA\u2019S DYNAMICS 324
Is stereocilia velocity or displacement feedback used in the cochlear amplifier? S. Lu, D.C. Mountain and A. Hubbard 326
1 Introduction 326
2 Method 327
3 Results 328
4 Discussion 330
Acknowledgments 331
References 331
Cellular basis of the cochlear amplifier K.H. Iwasa, B. Sul, J. Fang and G.P. Sinha 332
1. Introduction 332
2. OHC Electromotility 332
3. Energy Balance 333
4. Electromotility Frequency Limit 333
4.1. Without extracellular resistance 333
4.2. With extracellular resistance 334
5. E.ectiveness of Hair Bundle Motility 334
5.1. Mammalian ear 336
5.2. Avian ear 336
6. Conclusions 337
Acknowledgment 337
References 337
Tilt of the outer hair cell lattice: Origin of dual tuning tips and cochlear bandwidth A. Bell and T. Maddess 339
1 Introduction 339
2 Methods 340
3 Results 341
3.1 Apex-to-Base Trends 342
4 Discussion and Conclusion 343
Acknowledgments 344
References 344
Comments and Discussion 345
Acoustic streaming in the cochlea F. B枚hnke and M. Scharff 348
1 Introduction 348
2 Mathematical Formulation 348
2.1 Acoustic subproblem 349
2.2 Acoustic streaming subproblem 349
Acknowledgments 350
References 350
Comments and Discussion 350
Hook region represented in a cochlear model C.R. Steele, N. Kim and S. Puria 352
1 Introduction 352
2 Mathematical Analysis 352
2.1 Fast wave 353
2.2 Slow traveling wave 353
2.3 Evanescent wave 354
2.4 Computational procedure 354
3 Results 355
4 Conclusion 356
Acknowledgments 356
References 357
Comments and Discussion 357
Cochlear modeling using \u201ctime-averaged Lagrangian\u201d method: Comparison with VBM, PST, and ZC measurements Y. Yoon, N. Kim, S. Puria and C.R. Steele 359
1 Introduction 359
2 Method and Results 359
2.1 BM velocity with feed-forward (push) / feed-backward (pull) mechanism 360
2.2 Intracochlear pressure 361
2.3 Cochlear input impedance 362
3 Discussion 363
Acknowledgments 363
References 364
Comments and Discussion 364
A lumped-element model of the apical cochlea at low frequencies T. Marquardt and J. Hensel 366
1 Summary 366
Acknowledgment 368
References 368
Cochlear mechanics: A sideways look A.R. Gardner-Medwin 369
1 The extent of intrinsic damping 369
2 The nature of the inertial mass 369
3 The consequence of Outer Hair Cell (OHC) depolarisation 369
4 The role of active negative stiffness 370
5 The significance of OHC membrane capacitance 370
References 371
Nonlinear responses of a nonlinear cochlear model with the function of an outer hair cell model Y. Murakami and M. Unoki 372
1. Introduction 372
2. Methods 373
3. Results 375
4. Discussion 377
Acknowledgments 377
References 378
The influence on predicted harmonic generation of the position of the nonlinearity within micromechanical models J. How, S.J. Elliott and B. Lineton 379
1 Summary 379
References 380
Brownian energy depot model of the BM-OHC system Y. Zhang, C.K. Kim, K.-J.-B. Lee and Y. Park 381
1. Introduction 381
2. Energy Depot Model with Braking Mechanism 381
3. Results and Discussion 382
4. Summary 385
Acknowledgment 385
References 385
Conjoined cochlear models: The TWAMP and the sandwich A. Hubbard 387
1 Introduction 387
2 The TWAMP 387
3 The Sandwich model of the cochlea 388
4 The conjoined models 388
5 Discussion 389
References 389
SECTION VI HAIR CELLS AND ELECTRO-MECHANICAL TRANSDUCTION 390
Firing up the amplifier: Temperature, pressure and voltage jump studies on OHC motor capacitance J. Santos-Sacchi, L. Song and X. Li 392
1 Introduction 392
2 Methods 393
3 Results 394
3.1 Voltage jumps induce time dependent changes in NLC 394
3.2 Pressure jumps induce time dependent changes in NLC 395
3.3 Temperature jumps induce time dependent changes in NLC 395
4 Discussion 396
Acknowledgments 398
References 398
Comments and Discussion 399
Modeling the cochlear microphonic in prestin knockout mice M.A. Cheatham, K. Naik, J. Siegel and P. Dallos 400
1 Introduction 400
2 Methods 400
3 Results and Discussion 401
Acknowledgments 405
References 405
Using a large scale computational model to study the effect of longitudinal and radial electrical coupling in the cochlea P. Mistr铆k and J.F. Ashmore 406
1 Introduction 406
1.1. Cochlear amplification in 3-dimensions 406
2 Methods 407
2.1 Computational techniques 407
2.2 Parameter values 408
3 Results 408
4 Discussion 410
Acknowledgments 411
References 411
Comments and Discussion 412
Voltage and frequency dependence of charge transfer by prestin: An electro-diffusion model S. Sun, B. Farrell, M. Chana, S. Feng, G. Oster, W.E. Brownell and A. Spector 414
1 Introduction 414
2 Model 415
3 Results and Discussion 416
Acknowledgments 419
References 419
Topological characterization by atomic force microscopy of prestin in the plasma membrane of prestin-transfected Chinese hamster ovary cells using quantum dots H. Wada, M. Murakoshi, K. Iida and S. Kumano 420
1 Summary 420
Acknowledgments 421
References 421
Membrane composition tunes the outer hair cell motor L. Rajagopalan, J. Sfondouris, J.S. Oghalai, F.A. Pereira and W.E. Brownell 422
1 The outer hair cell lateral wall and its membrane-based motor 422
2 Results 423
2.1 Effect of membrane cholesterol on outer hair cell function 423
2.2 Membrane cholesterol effects on prestin-expressing HEK 293 cells are similar to those in OHCs 423
2.3 Effect of cholesterol concentration on peak and magnitude of charge movement 424
2.4 Effect of docosahexaenoic acid on peak and magnitude of charge movement 425
2.5 Modulation of cochlear function by cholesterol 425
3 Discussion 426
3.1 OHC membrane cholesterol decreases during development 426
3.2 Implication of membrane cholesterol for prestin function 426
3.3 Membrane cholesterol and the cochlear amplifier 426
Acknowledgments 427
References 427
Measurement of outer hair cell electromotility using a fast voltage clamp M.G. Evans and R. Fettiplace 429
1 Summary 429
Acknowledgments 431
References 431
Assessment of the activity of purified prestin and the effect of salicylate on prestin-chloride binding studied by isothermal titration calorimetry K. Iida, M. Murakoshi, S. Kumano, H. Wada, K. Tsumoto, K. Ikeda, T. Kobayashi and I. Kumagai 432
1 Summary 432
Acknowledgments 433
References 433
Increase in the activity by mutations of the motor protein prestin S. Kumano, K. Iida, M. Murakoshi, H. Wada, K. Tsumoto, K. Ikeda, I. Kumagai and T. Kobayashi 434
1 Summary 434
Acknowledgments 435
References 435
Prestin distribution in rat outer cells \u2013 An ultrastructural study S. Mahendrasingam, D.N. Furness, R. Fettiplace and C.M. Hackney 436
1 Introduction 436
2 Materials and Methods 437
3 Results 438
4 Discussion 440
Acknowledgments 441
References 441
SECTION VII HAIR BUNDLES AND MECHANO-ELECTRICAL TRANSDUCTION 442
Active hair-bundle motility by the vertebrate hair cell J-Y. Tinevez, P. Martin and F. J眉licher 444
1 Introduction 444
2 Methods 445
2.1 Mechanical stimulation of single hair bundles and Ca2+ iontophoresis 445
2.2 Theoretical description of active hair-bundle mechanics 446
3 Results 447
3.1 Three classes of active hair-bundle movements 447
3.2 Ca2+ involvement in active hair-bundle motility 448
3.3 Simulations 450
4 Discussion 450
Acknowledgments 452
References 452
In vivo dissection of fly auditory mechanotransduction J.T. Albert, B. Nadrowski, T. Effertz and M.C. G枚pfert 454
1 Introduction 454
2 Methods 455
3 Results 455
3.1 The fly\u2019s auditory transducers are mechanically gated, spring-operated ion channels 455
3.2 The fly\u2019s auditory transducers are mechanically adapting ion channels 457
4 Discussion 458
Acknowledgments 459
References 459
Transducer-based active amplification in the hearing organ of drosophila melanogaster B. Nadrowski, J.T. Albert and M.C. G枚pfert 460
1 Introduction 460
2 Methods 461
3 Results 461
3.1 Transducer-based model of the Drosophila hearing organ 461
3.2 Response to force steps 462
3.3 Linear response function, free fluctuations, deviation from thermal equilibrium 463
4 Discussion 463
Acknowledgments 464
References 464
The dynein motor is the basis of active oscillations of mosquito antennae B. Warren, A.N. Lukashkin and I. J. Russell 466
1 Summary 466
Acknowledgments 467
References 467
Trafficking of aminoglycosides into endolymph in vivo Q. Wang and P.S Steyger 468
1 Introduction 468
2 Materials and Methods 468
3 Results 470
4 Discussion 470
Acknowledgments 471
References 471
Big and powerful: A model of the contribution of bundle motility to mechanical amplification in hair cells of the bird basilar papilla C. K枚ppl, K.H. Iwasa and B. Sul 473
1 Introduction 473
2 Methods 474
3 Results 474
3.1 Values for morphological parameters 474
3.2 The morphological factor for upper frequency limit 475
3.3 Predicted upper frequency limit of effective hair-bundle forces 476
4 Discussion 476
4.1 Are hair-bundle forces likely to be effective in the avian frequency range? 476
4.2 Can the model account for species-specific differences? 477
Acknowledgments 477
References 477
The interplay between active hair bundle mechanics and electromotility in the cochlea D. 脫 Maoil茅idigh and F. J眉licher 480
1. Introduction 480
2. Methods 481
3. Results 482
4. Discussion 483
References 483
Mechanical properties of coupled hair bundles K. Dierkes, B. Lindner and F. J眉licher 486
1. Summary 486
References 487
Connections between stereociliary rootlets and lateral wall: A possible route for interactions between bundle and prestin based cochlear amplification? D.N. Furness, S. Mahendrasingam and C.M. Hackney 488
1 Introduction 488
2 Materials and Methods 488
3 Results 489
4 Discussion 489
Acknowledgments 492
References 492
SECTION VIII DISCUSSION 494
Edited transcripts of the open discussion session held at Keele University on July 31, 2008 C.A. Shera and D.C. Mountain 496
1. Introduction 496
2. Experimental evidence of power amplification 497
3. Overcoming the outer hair cell\u2019s time constant 505
4. Stimulating inner hair cells 511
5. Differences between the base and apex of the cochlea 515
6. The role of compression waves in forwards transduction 516
7. Robustness of measurement techniques 519
8. Tectorial membrane motion 521
9. Directions for future study 523
Author Index 534