| Preface | 5 |
|---|
| Contents | 6 |
|---|
| Contributors | 8 |
|---|
| Chapter 1 | 13 |
|---|
| Casting Light on Neural Function: A Subjective History | 13 |
| 1.1 Imaging of Neural Function | 19 |
| 1.1.1 Endogenous Chromophores | 19 |
| 1.1.2 Optical Reporters | 20 |
| 1.1.3 Functional Imaging | 20 |
| 1.1.4 Calcium Imaging | 21 |
| 1.1.5 Fast Intrinsic Signals | 23 |
| 1.1.6 Neural Investigation | 31 |
| 1.1.7 Technical Progress | 31 |
| 1.1.8 Future Directions | 33 |
| References | 35 |
| Chapter 2 | 38 |
|---|
| Fluorescent Sensors of Membrane Potential that Are Genetically Encoded | 38 |
| 2.1 Introduction | 38 |
| 2.2 First Generation FP Voltage Sensors | 40 |
| 2.3 Second Generation FP Voltage Sensors | 44 |
| 2.4 Next Generation FP Voltage Sensors | 47 |
| 2.4.1 Linker Optimized Variants | 47 |
| 2.4.2 Alternative FP Colors | 47 |
| 2.4.3 Alternative Designs | 48 |
| 2.5 Genetic Targeting of Neurons | 48 |
| 2.6 Genetically Encoded Sensors of Membrane Potential Compared to Alternative Targeting Approaches | 49 |
| 2.7 Signal-to-Noise Considerations | 50 |
| 2.8 Capacitative Load and Other Possible Caveats | 51 |
| 2.9 Future Directions | 51 |
| References | 52 |
| Chapter 3 | 55 |
|---|
| The Influence of Astrocyte Activation on Hemodynamic Signals for Functional Brain Imaging | 55 |
| 3.1 Brief Review of Hemodynamic Signals | 55 |
| 3.1.1 The BOLD Signal and Its Components | 56 |
| 3.1.2 Intrinsic Signal Imaging Relies on Similar Signals as BOLD | 56 |
| 3.1.3 Origin and Complexity of Hemodynamic Signal Components | 57 |
| 3.2 Astrocytes and Their Link with Neurons and the Vasculature | 58 |
| 3.2.1 Synaptic Inputs to Astrocytes | 59 |
| 3.2.2 Activation of Calcium Signaling in Astrocytes | 59 |
| 3.3 Role of Astrocytes in Hemodynamic Signaling | 60 |
| 3.3.1 Astrocytes and Hemodynamic Responses | 60 |
| 3.3.2 Response Specificity of Astrocytes | 61 |
| 3.3.3 Role of Astrocytes in Hemodynamic Signaling | 63 |
| 3.4 Conclusions and Outstanding Issues | 69 |
| 3.4.1 Astrocytes and Neurovascular Coupling | 69 |
| 3.4.2 Neural Activity, Astrocyte Activity, and Hemodynamic Response Parameters | 70 |
| 3.4.3 Effects of Anesthesia on Astrocyte Responses | 70 |
| References | 71 |
| Chapter 4 | 75 |
|---|
| Somatosensory: Imaging Tactile Perception | 75 |
| 4.1 Introduction | 76 |
| 4.2 Methodology of Optical Imaging of Primary Somatosensory Cortex in New World Monkeys | 77 |
| 4.2.1 The Somatosensory Optical Imaging Signal | 77 |
| 4.2.2 Relationship of Tactile Stimulation with the Optical Signal | 78 |
| 4.3 Somatotopic Representation in Primary Somatosensory Cortex | 79 |
| 4.3.1 Topography in Somatosensory Cortex | 79 |
| 4.3.2 Optical Imaging of Cortical Topography in Anesthetized Monkeys | 79 |
| 4.3.3 Optical Imaging of Cortical Topography in Alert Monkeys | 80 |
| 4.3.4 Correlations of Optical Imaging and fMRI Maps | 83 |
| 4.4 Representation of Perception in Primary Somatosensory Cortex | 85 |
| 4.4.1 The Funneling Illusion | 85 |
| 4.4.2 Two-Point Stimulation Produces Cortical Merging in Area 3b | 85 |
| 4.4.3 Intensity of Funneling Percept | 87 |
| 4.4.4 Tactile Funneling Illusion Revealed by High-Resolution fMRI | 89 |
| 4.5 Modality Representation in SI | 90 |
| 4.5.1 “Labeled Lines” in Touch | 90 |
| 4.5.2 Presence of Interdigitated Multiple Maps | 91 |
| 4.5.3 Relationship of Vibrotactile Domains with Somatotopy | 93 |
| 4.6 A New Model of Functional SI Organization | 94 |
| References | 96 |
| Chapter 5 | 103 |
|---|
| How Images of Objects Are Represented in Macaque Inferotemporal Cortex | 103 |
| 5.1 Introduction | 103 |
| 5.2 Optical Intrinsic Signal Imaging (OISI) in IT Cortex | 105 |
| 5.3 Evidence for the Columnar Organization with Respect to the Critical Features in Area TE | 107 |
| 5.4 Object Representation by Combinations of Activity Spots in Area TE | 109 |
| 5.5 Representation of Configurational Information Appeared in Object Images | 113 |
| 5.6 Face Neurons in Area TE as Ones that Represent Facial Configuration | 117 |
| 5.7 Object Representation at Different Levels: Columns and Single Cells Within a Column | 120 |
| 5.8 Summary and Discussion | 124 |
| References | 126 |
| Chapter 6 | 128 |
|---|
| Optical Imaging of Short–Term Working Memory in Prefrontal Cortex of the Macaque Monkey | 128 |
| 6.1 Introduction | 128 |
| 6.2 Prefrontal Delay Period Activity Encodes Short–Term Working Memory | 129 |
| 6.3 Does Prefrontal Cortex Contain Clustered Functional Organization? | 131 |
| 6.4 Topographic Organization of Prefrontal Cortex | 132 |
| 6.5 Is There Spatial Organization for Memory Location? | 133 |
| 6.6 Is There a Signal for Suppression in Prefrontal Cortex? | 138 |
| 6.7 Summary | 140 |
| References | 140 |
| Chapter 7 | 143 |
|---|
| Intraoperative Optical Imaging of Human Cortex | 143 |
| 7.1 The Intrinsic Optical Signal | 144 |
| 7.1.1 Neurovascular Coupling | 145 |
| 7.2 The History of Human IOS | 145 |
| 7.3 Imaging Normal Cortical Architecture | 146 |
| 7.3.1 Somatosensory Cortex | 146 |
| 7.3.2 Language Cortex | 149 |
| 7.4 Imaging Pathologic Cortical Activity | 152 |
| 7.4.1 Cortical Stimulation | 152 |
| 7.4.2 Triggered Afterdischarges | 154 |
| 7.4.3 Spontaneous Seizures | 155 |
| 7.4.4 Spontaneous Interictal Spikes | 156 |
| 7.5 Noise Reduction | 158 |
| 7.5.1 Periodic Motion | 158 |
| 7.6 Aperiodic Motion | 160 |
| 7.7 Transient Linear Motion | 162 |
| 7.8 Future Directions | 163 |
| 7.9 Summary | 164 |
| References | 164 |
| Chapter 8 | 166 |
|---|
| Using Optical Imaging to Investigate Functional Cortical Activity in Human Infants | 166 |
| 8.1 How Does NIRS on Infants Work? | 167 |
| 8.2 Review of the Existing Studies Using NIRS on Infants | 168 |
| 8.3 Preliminary Studies on Motor and Visual Responses | 170 |
| 8.4 Methodological Advances | 177 |
| 8.5 Preliminary Studies on Auditory Activation | 178 |
| 8.6 Speculations About the Future | 181 |
| 8.7 Probe Design | 181 |
|
|
