Reprogramming the Brain (eBook)

Cover 1
Contents 6
List of contributors 10
Foreword 14
Section I: Basis for Cortical Rewiring 16
Chapter 1. Visual activity and cortical rewiring: activity-dependent plasticity of cortical networks 18
Introduction 18
Developmental plasticity of sensory pathways: rewiring retinal inputs into the auditory thalamus 20
Novel inputs alter functional specificity in the cortex: anatomical, physiological and behavioral consequences of rewiring 20
Gene expression and the molecular mechanisms of rewiring 22
Implications of the rewiring model for human disability and comparative neurology 23
Conclusions 24
References 24
Section II: Molecular Basis for Signaling in CNS and Memory 28
Chapter 2. Receptor tyrosine kinase B-mediated excitatory synaptogenesis 30
Introduction 30
History 30
TrkB mediates synaptogenesis 31
References 36
Chapter 3. Signal transduction mechanisms in memory disorders 40
Introduction 40
The importance of signaling cascades within the hippocampus 40
Human mental retardation syndromes 43
Conclusion 51
References 52
Section III: The Aging Brain 58
Chapter 4. Altered brain activity in healthy seniors: what does it mean? 60
Introduction 60
Overview of findings 61
Discussion 67
Conclusions and future directions 69
References 69
Chapter 5. Cortical reorganization in the aging brain 72
Introduction 72
Rat aging 76
Human aging 85
The third brain: interventions are no time-travel „ insight from intervention studies 90
Conclusion 91
Acknowledgments 91
References 91
Chapter 6. Brain plasticity and functional losses in the aged: scientific bases for a novel intervention 96
Introduction 97
Cognitive decline in aging is progressive and can become pathological 97
Root causes of age-related cognitive decline 98
Learning changes the brain through brain plasticity 99
Age-related cognitive decline is a problem of brain plasticity with negative consequences 101
Cognitive decline is driven by changes across brain systems 103
Age-related decline in rat 107
Remediation of acquired hand movement disorders 108
Up-regulating dopamine cell function in adult rats 109
Reversing language learning and reading impairments in children and young adults 110
Current approaches to treating cognitive decline have limited applicability and efficacy 111
Pharmacological approaches 111
Structure of the training program 113
Conclusions 117
Acknowledgments 117
References 117
Chapter 7. Cortical plasticity and rehabilitation 126
Factors that regulate plasticity 126
Influence of background stimuli on plasticity 129
Sensory input paired with controlled release of neuromodulators 129
Clinical conclusions 132
Acknowledgments 134
References 134
Chapter 8. Neural mechanisms of prefrontal cortical function: implications for cognitive rehabilitation 138
Introduction 138
Neural mechanisms underlying prefrontal cortical function 140
Dysfunction of frontal systems in aging and disease 145
Cognitive rehabilitation of PFC function 149
Development of biomarkers to assess rehabilitation of PFC function 151
Conclusions 152
References 152
Section IV: Brain Injury 156
Chapter 9. Recovery from aphasia following brain injury: the role of reorganization 158
Introduction 158
How does reorganization fit into recovery? 158
Evidence for reorganization in aphasia 160
The location of reorganization „ evidence from functional imaging 162
Factors affecting the location and extent of reorganization 164
Factors that facilitate reorganization 166
Unanswered questions and areas of future research 168
References 168
Chapter 10. Relocation of specific visual functions following damage of mature posterior parietal cortex 172
Introduction 172
Protocols and procedures 174
Posterior parietal loci contributing to visual orienting and landmark discrimination 177
Task-specific adaptive neuroplasticity following lesions of pMSs cortex 177
Identifying the locus for cortical reprogramming 180
Removal of aMSs cortex prevents expression of adaptive neuroplasticity 182
Is there a ‘‘price to pay’’ for cerebral reprogramming? 182
Relocation of cerebral functions in other systems 184
Acknowledgments 184
References 184
Chapter 11. A SPECT study of language and brain reorganization three years after pediatric brain injury 188
Introduction 188
Methods 190
Results 193
Discussion 195
Abbreviations 198
Acknowledgments 198
References 198
Chapter 12. Activation of neural stem and progenitor cells after brain injury 202
Brain injury and plasticity 202
Neural stem and progenitor cells in the adult brain 203
Tracking neural stem and progenitor cells in vivo 205
Activation of neural stem and progenitor cells after injury 205
Abbreviations 209
Acknowledgments 209
References 210
Chapter 13. Cognitive neural plasticity during learning and recovery from brain damage 214
Introduction 214
Development and learning 215
Recovery from TBI 217
Long-term implications of plasticity 218
Acknowledgments 219
References 220
Chapter 14. Novel cell therapy approaches for brain repair 222
Introduction 222
Umbilical cord blood cells: new vision or novel assets 224
Umbilical cord blood cells in treatment of diseased brain and spinal cord 226
Conflict of interest disclosure 232
References 232
Chapter 15. Recovery of motor function after stroke 238
Introduction 238
Background 239
Animal studies on the effect of motor cortex stimulation 240
Clinical investigations in motor cortex stimulation 241
Acknowledgments 242
References 242
Section V: Spinal Cord 244
Chapter 16. Functional plasticity following spinal cord lesions 246
General introduction 246
Changes in reflex pathways after spinal cord injury 247
Locomotor recovery after spinal cord lesions 262
Reflex pathways and spinal locomotion 264
Concluding remarks 267
Acknowledgments 267
References 267
Chapter 17. The education and re-education of the spinal cord 276
Introduction 276
Activity-dependent spinal cord plasticity during normal life 278
Sites and mechanisms of activity-dependent spinal cord plasticity 283
Principles underlying activity-dependent plasticity and their relations to behavioral change 284
Theoretical significance of activity-dependent spinal cord plasticity 287
Possible clinical uses of activity-dependent spinal cord plasticity 288
Acknowledgments 290
References 290
Section VI: Prostheses and Plasticity 296
Chapter 18. Cochlear implants: cortical plasticity in congenital deprivation 298
Introduction 298
Electrical stimulation of the auditory nerve 300
Plasticity, development, and deprivation 300
Developmental plasticity 308
Clinical relevance 321
Conclusions 322
Acknowledgments 323
References 323
Chapter 19. Disrupting the brain to guide plasticity and improve behavior 330
An intrinsically plastic nervous system 330
Variable brain–behavior relations 331
Plasticity and genetics 334
Plasticity in the setting of brain injury: the risk of change and the opportunity for intervention 336
Conclusions 342
Acknowledgments 342
References 343
Section VII: Pain and Tinnitus 346
Chapter 20. Plasticity in brain processing and modulation of pain 348
Introduction 348
What are the dimensions of pain and how do they interact? 349
Ascending nociceptive pathways to the brain 351
Which central targets of ascending pathways participate in sensory and emotional aspects of pain? 353
Electrophysiological studies of central neurons that integrate nociceptive with other inputs 355
Are there multiple ways that pain can be processed or represented in the brain? 357
Modulating pain and neural representations of pain 358
Can the different dimensions of pain be selectively modulated? 361
What are the relationships between activity in the pain matrix and pain-related experiences? 362
How do we optimally conceptualize mind–brain relationships in efforts to understand psychological modulation of pain? 363
References 364
Chapter 21. Plasticity of pain-related neuronal activity in the human thalamus 368
Introduction 368
The Vc region of the thalamus 369
Reorganization of Vc after nervous system injury 371
Acknowledgments 376
References 376
Chapter 22. Neural plasticity in tinnitus 380
Introduction 380
Etiology and nature of central tinnitus 381
Functional abnormalities associated with subjective tinnitus 382
Treatment of subjective tinnitus 384
References 385
Subject Index 388
Colour Plate Section 396