Functional characterization of memory-encoding networks after medial temporal lobe resection

학위논문 (박사)-- 서울대학교 대학원 자연과학대학 협동과정 뇌과학전공, 2017. 8. 정천기.Considering the central position of the hippocampus as a densely interconnected hub in brain networks and its role in episodic memory, medial temporal lobe resection, including the hippocampus, should modify recruitment and strength of connectivity of functional memory network. However, functional memory encoding network in patients with medial temporal lobe resection has not been well characterized, which could provide a clue for new therapeutic targets for people with memory impairment. The aim of present study is to understand how brain supports normal episodic memory function without unilateral medial temporal lobe structures in a new perspective of functional interactions of brain network. Thirty-seven patients who underwent unilateral medial temporal lobe resection for the treatment of medically intractable temporal lobe epilepsy (17 left, 20 rightmedian age 34 years) and 24 healthy controls (median age 32 years) were studied. To understand stable and an effective memory network, patients who underwent resective surgery at least 1 year before fMRI scanning and who have normal range of postoperative memory capacity were recruited. All subjects performed functional MRI memory encoding paradigm of words and figures. Hippocampal regions of interest analysis revealed that greater activation of hippocampus contralateral to the resection was related to higher memory scores in both patient groups. Whole-brain functional activation analysis revealed that well-known task-negative areas including the medial prefrontal cortex were less deactivated in patient groups than healthy controls. Task-based functional connectivity analysis revealed that the right medial prefrontal cortex showed stronger interactions with widespread brain areas including hippocampus contralateral to the resection during successful word encoding in left surgery group and during successful figure encoding in right surgery group. Furthermore, the strengths of right medial prefrontal cortex functional connectivity predict individual memory capacity of patients. The results of present study suggest that hyper-connectivity of medial prefrontal cortex may play a pivotal role in episodic memory function with the absence of functional connections of medial temporal lobe. These results, therefore, further implicated in the studies of brain stimulation toward enhancing memory for people who suffer from medial temporal lobe-dysfunction-related memory disturbances by providing possible new target area of medial prefrontal cortex.SECTION I. INTRODUCTION 1 CHAPTER 1: Memory and Medial Temporal Lobe 1 1.1. Human Memory System 1 1.2. Structures and Connections of the MTL 3 1.3. MTL-dysfunction-related Memory Deficits 4 1.3.1. MTL Lesion Studies 4 1.3.2. Memory Deficits in Neurological Disorders 5 CHAPTER 2: Epilepsy and Epilepsy Surgery 8 2.1. Definition of Epilepsy 8 2.2. Temporal lobe Epilepsy 9 2.3. Epilepsy Surgery 11 2.3.1. Aims of Surgery 11 2.3.2. Resective Surgery for TLE 12 2.4. Consequence of TLE Surgery 14 2.4.1. Seizure Outcome 14 2.4.2. Cognitive Outcome 16 CHAPTER 3: Functional Neuroimaging Studies of Episodic Memory 18 3.1. Introduction of fMRI Memory Studies 18 3.2. MTL Regions of Interest 19 3.2.1. MTL Activations in Healthy Controls 19 3.2.2. MTL Activations in Patients with TLE and MTLR 20 3.3. Large-scale Memory Network 21 3.3.1. Episodic Memory-related Whole-brain Regions 21 3.3.2. Introduction to Functional Connectivity of fMRI 26 3.3.3. Resting-state Network and Memory. 29 3.3.4. Task-related Memory Network 33 3.4. Findings from Brain Stimulation Studies 36 CHAPTER 4: Purpose of the Present Study 39 SECTION II. EXPERIMENTAL STUDY 42 CHAPTER 5: Materials and Methods 42 5.1. Subjects 42 5.2. Neuropsychological Tests 46 5.3. Magnetic Resonance Data Acquisition 47 5.4. Memory Task Paradigm 48 5.5. Data Analysis 51 5.5.1. Preprocessing 51 5.5.2. Event-related Analysis 52 5.5.3. Hippocampal ROIs 54 5.5.4. Task-based Functional Connectivity 54 CHAPTER 6: Results 56 6.1. Neuropsychological Performance 56 6.2. Behavioral Results 58 6.3. Hippocampal ROI Activations 59 6.4. Whole-brain Activations during Memory Encoding 60 6.4.1. Less Activation in MTLR than in HC 63 6.4.2. Greater Activation in MTLR than HC 64 6.5. Task-based Functional Connectivity 67 SECTION III. DISCUSSION AND CONCLUSION 75 CHAPTER 7: Discussion 75 7.1. Behavioral Results 75 7.2. Hippocampal ROI Activities 76 7.3. Whole-brain Activations during Memory Encoding 77 7.4. Functional Interactions during Memory Encoding 79 7.5. Implications of the Present Study 81 7.6. Methodological Considerations and Future Directions 83 CHAPTER 8: Conclusion 85 References 86 Abstract in Korean 103Docto

사료내 에너지와 아미노산 수준이 돼지의 성장성적, 생리학적 반응 및 번식성적에 미치는 영향

학위논문 (박사)-- 서울대학교 대학원 : 농업생명과학대학 농생명공학부, 2018. 8. 김유용.Effects of Dietary Energy and Amino Acid Levels on Growth Performance, Physiological Responses and Reproductive Performance in Swine The objectives of this research described were 1) to evaluate the effect of dietary energy and amino acid levels on growth performance, blood profiles, meat quality and economic analysis in grower - finisher pigs, 2) to determine the effect of dietary amino acid levels on body changes, reproductive performance, blood profiles and milk composition in gestating to lactating sows, and 3) to investigate the effect of dietary valine:lysine ratios on body changes, reproductive performance, blood profiles and milk composition in lactating sows. Experiment I. Effect of Dietary Energy and Amino Acid Levels on Growth Performance, Blood Profiles, Meat Quality and Economic Analysis in Grower - finisher Pigs This experiment was conducted to evaluate the effect of dietary energy and amino acid levels on growth performance, blood profiles, meat quality and economic analysis in grower - finisher pigs. A total of 180 cross-bred pigs ([Yorkshire × Landrace] × Duroc) with an initial mean body weight of 29.5 ± 4.04 kg were allotted to one of six treatments based on 2 × 3 factorial arrangement with 3 replicates. The first factor is two levels of metabolizable energy (ME) and the second factor is three different levels of amino acid (AA), and treatments were 1) LL: 3,200 kcal of ME/kg, NRC (1998) AA requirementOverall Summary 1 Contents 5 List of Tables 8 List of Figures 10 List of Abbreviation 11 Chapter I. General Introduction 12 Chapter II. Review of Literature 14 Importance of Nutritional Factors in Swine 14 Energy 14 Protein and Amino Acids 15 Amino Acids Metabolism in Swine 16 Lysine Metabolism 16 Catabolism and Energy Source 16 Physiological Functions of Lysine 17 Lysine Mechanism and Perspectives 17 Methionine Metabolism 18 Methionine and Cysteine 18 Tryptophan Metabolism 19 Threonine Metabolism 20 Valine Metabolism 22 Ideal Amino Acid Balance 23 Gestating Sows 23 Lactating Sows 24 Importance of Milk 25 Yield of Colostrum and Milk 25 Composition of Colostrum and Milk 26 Literature Cited 28 Chapter III. Effect of Dietary Energy and Amino Acid Levels on Growth Performance, Blood Profiles, Meat Quality and Economic Analysis in Grower - finisher Pigs Abstract 35 Introduction 36 Materials and Methods 37 Results 41 Discussion 42 Conclusion 45 References 46 Chapter IV. Effect of Dietary Amino Acid Levels on Body Changes, Reproductive Performance, Blood Profiles and Milk Composition in Gestating to Lactating Sows Abstract 59 Introduction 60 Materials and Methods 61 Results 64 Discussion 65 Conclusion 68 References 69 Chapter V. Effect of Dietary Valine:Lysine Ratios on Body Changes, Reproductive Performance, Blood Profiles and Milk Composition in Lactating Sows Abstract 83 Introduction 84 Materials and Methods 85 Results 88 Discussion 89 Conclusion 92 References 93 Chapter VI. Overall Conclusion 103 Chapter VII. Summary in Korean 105 Acknowledgement 109 List of Tables Chapter III. Experiment I Table 1. Formulas and chemical compositions of the experimental diets during 0 - 3 weeks 49 Table 2. Formulas and chemical compositions of the experimental diets during 4 - 6 weeks 50 Table 3. Formulas and chemical compositions of the experimental diets during 7 - 10 weeks 51 Table 4. Formulas and chemical compositions of the experimental diets during 11 - 14 weeks 52 Table 5. Effect of dietary energy and amino acid levels on growth performance in grower - finisher pigs 53 Table 6. Effect of dietary energy and amino acid levels on blood profiles in grower - finisher pigs 54 Table 7. Effect of dietary energy and amino acid levels on immune response in grower - finisher pigs 55 Table 8. Effect of dietary energy and amino acid levels on carcass traits of the longissimus muscle 56 Table 9. Effect of dietary energy and amino acid levels on meat color 57 Table 10. Carcass grading system for pigs in Korea 58 Table 11. Pork grade score in this research 58 Table 12. Effect of dietary energy and amino acid levels on economic analysis in finishing pigs 58 Chapter IV. Experiment II Table 1. Formulas and chemical compositions of the experimental diets in gestation and lactation 74 Table 2. Effect of dietary amino acid levels on body changes in gestating sows 75 Table 3. Effect of dietary amino acid levels on body changes in lactating sows 76 Table 4. Effect of dietary amino acid levels on reproductive performance in lactating sows 77 Table 5. Effect of dietary amino acid levels on litter performance in lactating sows 78 Table 6. Effect of dietary amino acid levels on blood profiles in gestating sows 79 Table 7. Effect of dietary amino acid levels on blood profiles in lactating sows and their progeny 80 Table 8. Effect of dietary amino acid levels on blood amino acid concentrations in sows 81 Table 9. Effect of dietary amino acid levels on milk composition during lactation 82 Chapter V. Experiment III Table 1. Formulas and chemical compositions of the experimental diets in lactation 96 Table 2. Effect of dietary Val:Lys ratios on body changes in lactating sows 97 Table 3. Effect of dietary Val:Lys ratios on reproductive performance in lactating sows 98 Table 4. Effect of the dietary Val:Lys ratios on litter performance in lactating sows 99 Table 5. Effect of dietary Val:Lys ratios on blood profiles in lactating sows and their progeny 100 Table 6. Effect of dietary Val:Lys ratios on blood amino acid concentrations in lactating sows and their progeny 101 Table 7. Effect of dietary Val:Lys ratios on milk composition during lactation 102 List of Figures Chapter II. Review of Literature Figure 1. Lysine catabolism in monogastric animals 16 Figure 2. Metabolic pathways of sulfur amino acids 19 Figure 3. Metabolic pathways of tryptophan 21Docto