Insects are among the most diverse and adaptable organisms on Earth. They have long been our chief competitors for food and are responsible for spreading devastating afflictions such as malaria and encephalitis. The insects’ ability to thrive is due in large part to their well-developed sensory systems, which present a host of novel physiological, biochemical, and behavioral attributes that underlie their remarkable feats of sensory performance. Methods in Insect Neuroscience is the first text to showcase the tremendous variety of methods that are available to study the sensory capabilities of insects. It covers the complete spectrum of sensory modalities in insects, from vision and audition, to chemoreception and multimodal processing. The book is designed to serve as a how to guide for putting into practice a wide range of techniques, including behavioral observation, brain imaging, single- and multi-unit electrophysiology, computer modeling/signal processing, and robotics to address innumerable questions. A truly multidisciplinary synthesis of neurobiological, behavioral, and computational approaches to sensory-information processing is most likely to yield our richest understanding of the mechanisms that underlie sensation and perception. In that spirit, this book contains chapters by leading neuroethologists, comparative biologists, neuroscientists, computational biologists, geneticists, and bioengineers who have adopted insects as their models. Their hard work and dedication is evident in the quality of detail contained in every chapter. This book is intended for seasoned neuroscientists looking for state-of-the-art information, as well as discussions on the open-ended questions facing sensory neuroscience today. It is also intended as a primer for newcomers utilizing insects to embark on a study of sensory mechanisms.The opening section provides background information and references about the basic organization of the insect brain and the behavioral strategies used by insects to navigate their complex and varied environments. The latter sections are designed to provide more detailed information about specific sensory modalities and the tools that are used to study them.
Author(s): Thomas A. Christensen
Series: Frontiers in Neuroscience
Edition: 1
Publisher: CRC Press
Year: 2004
Language: English
Pages: 461
Front cover......Page 1
Frontiers in Neuroscience......Page 8
Preface......Page 12
About the Editor......Page 16
Contributors......Page 18
Table of Contents......Page 22
Introduction: Multimodal Signal Integration and Behavior......Page 26
1.1 Introduction......Page 28
1.2.1 Visual Pathways......Page 30
1.2.2 Chemosensory Pathways......Page 32
1.2.3 Mechanosensory Pathways......Page 34
1.3.1 Deutocerebrum......Page 35
1.3.2.1 Modality-Specific Topography......Page 36
1.3.2.2 Learning-Associated Heterosensory Interactions......Page 37
1.3.3 Central Complex......Page 38
1.4.1 Neurons Mediating Escape Responses......Page 39
1.4.2 Neurons Controlling Flight Course and Balance......Page 40
1.5 Centrifugal Modulation of Sensory Processing......Page 42
1.6 Conclusions and Outlook......Page 43
References......Page 44
Methods in Insect Sensory Ecology......Page 52
2.2 Sensory Signals and Ecology......Page 53
2.2.2 Sensory Systems and the Environment......Page 54
2.2.3 Costs and Constraints in Sensory Systems......Page 56
2.2.5 Identifying Sensory Signals......Page 58
2.3 Sensory Modalities......Page 59
2.3.1.1 Constraints on Insect Acoustic Communication......Page 60
2.3.1.2 The Insect Ear......Page 61
2.3.1.4 Hearing in Lepidoptera......Page 62
2.3.2 Vision......Page 63
2.3.2.1 Spatial Resolution and the Compound Eye......Page 64
2.3.2.2 Color Vision......Page 66
2.3.2.3 Polarization......Page 67
2.3.3 Chemoreception......Page 68
2.3.3.1 Classification of Semiochemicals......Page 69
2.3.3.3 Adaptive Use of Odor Information......Page 70
2.3.3.4 Antennae as Odor Detectors: GC-Electrophysiology......Page 72
2.3.4 Multimodal Stimuli......Page 75
2.4 Conclusions and Outlook......Page 76
Acknowledgments......Page 77
References......Page 78
Mechanosensation and Audition......Page 84
The Chordotonal Organ: A Uniquely Invertebrate Mechanoreceptor......Page 86
3.1 Introduction......Page 87
3.1.2 The Scolopidium......Page 89
3.2.1 Head and Associated Appendages......Page 90
3.2.2 Thorax......Page 91
3.2.2.1 Neck......Page 93
3.2.2.2 Wings......Page 94
3.2.2.3 Tympanal Organs......Page 95
3.2.4 Legs......Page 96
3.2.4.1 Joint Chordotonal Organs......Page 97
3.2.4.2 The Nonconnective Chordotonal Organs......Page 98
3.3.1 Histochemical Staining of Fixed Tissue......Page 99
3.3.3 Axonal Backfilling and Intracellular Dye Injection......Page 100
3.3.4.2 Subcellular Components and Associated Molecules......Page 101
3.4.1 Electron Microscopy and Immunogold Labeling......Page 103
3.4.1.3 Fixation Artifacts and Cryotechniques......Page 104
3.4.2 Genetics......Page 105
3.4.2.2 Localization of Gene Products......Page 106
3.4.2.3 Molecular Components of Chordotonal Organs......Page 107
3.4.2.4 Electrophysiological Recording in Genetic Studies......Page 110
3.5.1 Mechanically Activated Channels......Page 111
3.5.4 Use of Blocking Agents......Page 112
3.6.1 Mechanical Nature of the Stimulus......Page 113
3.6.2.1 Open-Loop vs. Closed-Loop Stimulation......Page 114
3.6.2.2 Probes......Page 115
3.6.2.3 Mechanical Drivers......Page 117
3.6.2.4 Stimulus Parameters and Waveforms......Page 118
3.6.3.1 Sound Stimulation......Page 119
3.6.3.3 Anechoic Conditions......Page 120
3.6.3.4 Waveforms......Page 121
3.7 Conclusions and Outlook......Page 122
References......Page 123
4.1 Introduction......Page 132
4.2.1 The Initiation of Free-Flight Maneuvers......Page 133
4.2.2 Aerodynamics......Page 135
4.2.3 Motor Control of Wing Kinematics......Page 139
4.3.1.1 Orthopteran Head Hairs......Page 140
4.3.1.2 Orthopteran and Lepidopteran Wing-Hinge Stretch Receptors......Page 142
4.3.1.3 Orthopteran Tegulae......Page 143
4.3.2 Mechanisms of Sensorimotor Integration......Page 145
4.4 Behavioral Psychophysics of Visuo-Mechanosensory Integration......Page 146
4.5 Conclusions and Outlook......Page 149
References......Page 150
Auditory Processing of Acoustic Communication Signals: Sensory Biophysics, Neural Coding, and Discrimination of Conspecific Songs......Page 154
5.1 Introduction......Page 155
5.2 Biophysics of Auditory Signal Transduction......Page 157
5.2.1 Conceptual Framework: Analysis and Comparison of Iso-Response Stimuli......Page 158
5.2.2 Mathematical Framework for Sensory Processing: LNLN Signal Cascades......Page 159
5.2.3 Firing Rates Reveal the Functional Form of the Intermediate Static Nonlinearity......Page 160
5.2.4 Firing Probabilities Reveal the Time Scales of Mechanical and Electrical Integration......Page 161
5.3.1 Disentangling Input-Driven and Output-Driven Adaptation in Vivo......Page 164
5.3.2 Phenomenological Model for Output-Driven Adaptation......Page 165
5.4.1 Mathematical Framework for Stochastic Spike Generation: Renewal Processes......Page 167
5.4.2 Summary of Results from Locusta migratoria......Page 169
5.5.1 Stimulus Reconstruction......Page 170
5.5.2 Information Theory......Page 172
5.5.3 Summary of Results......Page 173
5.6.1 Spike-Train Metrics and Discrimination Matrices......Page 174
5.6.2 Summary of Results......Page 176
5.7 Conclusions and Outlook......Page 177
References......Page 179
Vision......Page 182
6.1 Introduction......Page 184
6.2.1 Molecular Biology and Spectral Sensitivity......Page 187
6.2.2 Photochemistry of Visual Pigments......Page 189
6.3.1 Anatomy......Page 190
6.3.2 Phototransduction and Measuring Calcium in Fly Photoreceptors......Page 192
6.3.3 Fluorescence Microscopy and the Deep Pseudopupil of Mutant Fly Eyes......Page 193
6.3.4 Fly Photoreceptor Optics......Page 194
6.3.5 Angular and Spectral Sensitivity......Page 196
6.4.2 Retinal Heterogeneity......Page 198
6.4.3 Epi-illumination Microscopy and Eye Shine......Page 199
6.5 Conclusions and Outlook......Page 204
References......Page 206
7.1 Introduction......Page 210
7.2.1 Identifying Neural Networks......Page 212
7.2.2 Computational Properties of Synaptic Interactions......Page 215
7.3.1 Reliability of Neural Coding by Individual Nerve Cells......Page 219
7.3.2 Coding of Motion Information by Neural Populations......Page 225
7.4 Approaches to Investigate the Encoding of Natural Visual Stimuli......Page 226
7.5 Conclusions and Outlook......Page 231
References......Page 232
8.1 Introduction......Page 238
8.2.1 Motion-Detecting Circuits......Page 241
8.2.2.2 Subunit 2: The Temporal Low-Pass Filter plus Multiplier......Page 243
8.3 Locust Looming Detectors for Collision Avoidance......Page 246
8.3.1 The Rind and Bramwell Model of the Locust LGMD......Page 249
8.3.3 Feed-Forward Inhibition......Page 250
8.3.4 A Locust-Inspired Collision Sensor......Page 251
8.4 Honeybee Behavioral Strategies for Estimating Range and Distance Traveled......Page 252
8.5.1 Neural Model of Cricket Phonotaxis and Locomotion......Page 254
8.5.2 Integration of Optomotor Response with an Analog VLSI Chip......Page 255
References......Page 257
Molecular Characterization of Chemosensory Systems......Page 262
9.1 Introduction......Page 264
9.2.1 Bioinformatic Approaches......Page 265
9.3 Expression Patterns of Drosophila Taste Receptors......Page 267
9.3.2 In Situ Hybridization......Page 268
9.3.3 GAL4-UAS Expression System......Page 269
9.4.1 Proboscis Extension Response......Page 271
9.5 Single-Unit Electrophysiological Analysis......Page 272
9.6 Genetic Analysis of Taste Receptor Genes......Page 276
9.6.1 Genetic Screens for Taste Mutants......Page 277
9.6.2 The Trehalose Response Locus and Gr5a......Page 279
9.6.3 RNAi Analysis of Gr68a Function......Page 280
9.7 Heterologous Expression of Taste Receptors......Page 281
9.8 Conclusions and Outlook......Page 283
References......Page 284
Combining Molecular, Physiological, and Behavioral Tools to Study Insect Olfactory Processing......Page 290
10.1 Introduction......Page 291
10.2 Identification and Cloning of Olfactory Genes......Page 292
10.2.1.1 Bioinformatics/Genomics......Page 293
10.2.1.3 Random Sampling of cDNAs......Page 294
10.2.1.4 Differential/Subtractive Screening......Page 295
10.2.1.5 Sequence Similarity-Based Cloning......Page 297
10.2.2.1 Microarray Methods......Page 299
10.2.2.3 RNAi......Page 300
10.3 Assaying Function......Page 302
10.3.1.1 Electroantennographic Methods......Page 303
10.3.2 Heterologous/Transgenic Systems......Page 304
10.3.3 Behavioral Tools for Testing Reverse Genetics......Page 305
10.4 Conclusions and Outlook......Page 306
References......Page 307
Population Analysis of Sensory Systems......Page 312
11.1 Introduction......Page 314
11.2.1 Proboscis Extension Reflex in Flies......Page 317
11.2.2 Oviposition Behavior in Locusts......Page 318
11.2.3 Feeding and Food Sampling Behavior......Page 321
11.2.4 Leg Avoidance Behavior......Page 322
11.3 Taste Receptors and Peripheral Coding......Page 324
11.4 Local Circuits Controlling Limb Movements......Page 326
11.4.1 Anatomical Organization of Sensory Neurons......Page 327
11.4.2 Gustatory Pathways in Local Circuits......Page 331
11.4.3 Gustatory Coding by Interneurons and Motor Neurons......Page 333
11.5 Conclusions and Outlook......Page 336
Acknowledgments......Page 338
References......Page 339
Insect Olfactory Neuroethology - An Electrophysiological Perspective......Page 344
12.2 Probing the Peripheral Olfactory System......Page 345
12.2.1 The Electroantennogram......Page 346
12.2.2.1 Types of Electrodes......Page 347
12.3 Functional Characteristics of the Peripheral Olfactory System......Page 348
12.3.1 Selectivity of Olfactory Receptor Neurons......Page 349
12.3.2 Sensitivity of the Peripheral Olfactory System......Page 350
12.3.3 Encoding Stimulus Frequency in Olfactory Receptor Neurons......Page 351
12.4 Probing the Central Nervous System......Page 352
12.4.2 Whole-Cell Patch Clamp Technique......Page 353
12.5.1 Encoding Odor Quality......Page 354
12.5.2.1 Sensitivity of Antennal Lobe Neurons......Page 357
12.5.2.2 Intensity vs. Identity Coding......Page 358
12.5.3.1 Encoding Stimulus Frequency in Antennal Lobe Neurons......Page 360
12.5.3.2 Temporal Representation of Odors......Page 361
Acknowledgments......Page 363
References......Page 364
Optical Methods for Analyzing Odor-Evoked Activity in the Insect Brain......Page 374
13.1 Introduction......Page 375
13.1.2 Overview of Imaging Methods......Page 376
13.1.3 Abbreviations......Page 377
13.2.2.1 Saline Solution......Page 378
13.2.2.3 Stabilizing the Head: Waxes, Glues, etc.......Page 379
13.2.3 Animal Preparations......Page 381
13.2.3.1 Bees......Page 382
13.2.3.3 Flies......Page 385
13.3.1.1 Staining Technique......Page 386
13.3.1.3 Other Dyes......Page 387
13.3.1.4 Which Cells Are Stained?......Page 388
13.3.2 Afterstaining for Glomerular Mapping......Page 389
13.3.6 Single-Cell Staining......Page 392
13.3.7 Genetically Engineered Dyes......Page 394
13.4.1 The Light Source......Page 397
13.4.3 The Detector......Page 398
13.4.4 The System We Use......Page 399
13.4.5 Two-Photon Imaging......Page 402
13.5.1.2 Structure Identification......Page 403
13.5.2.2 Scattered Light Correction......Page 404
13.5.2.3 “Bleach” Correction......Page 407
13.5.3.1 Calculation of DF/F......Page 410
13.5.3.3 False-Color Coded Images......Page 411
13.5.3.5 Fitting Response Functions......Page 412
13.6 Conclusions and Outlook......Page 413
References......Page 414
A Primer on Multichannel Neural Ensemble Recording in Insects......Page 418
14.1.1 In the Beginning …......Page 419
14.2 Acquisition of Spike Data......Page 420
14.2.1 Analog-to-Digital Conversion and Spike Detection......Page 422
14.2.2 Thresholding......Page 423
14.3 Spike Sorting and Processing......Page 426
14.3.2 Template Matching and Other Sorting Methods......Page 428
14.3.3.2 Other Sources of Error......Page 429
14.3.3.3 Checking for Errors......Page 430
14.4.1 Cluster-Cutting Suites......Page 431
14.4.2 Review of MNER Hardware......Page 432
14.4.2.1 PC-Based Acquisition......Page 433
14.5.1 New Probe Designs......Page 434
14.6 Conclusions and Outlook......Page 436
References......Page 437
Appendix......Page 442
A......Page 448
C......Page 449
E......Page 451
G......Page 452
K......Page 453
M......Page 454
O......Page 455
R......Page 457
S......Page 458
T......Page 459
W......Page 460
