A thesis submitted to the Faculty of Medicine, University of the Witwatersrand, Johannesburg, for the degree of Doctor of Philosophy (Medicine) / Idiopathic Parkinson's disease remains one of the commonest neurodegenerative diseases known today. It causes incapacita ting symptoms untreated but when given replacement neurotransmitters, principally levodopa or dopamine, corrects the major features of the illness. The fundamental cause of nigral dopaminergic cell decline remains unknown, is not principally genetic, but may be due to abnormal hepatic handling of neurotoxins. One such putative neurotovin is MPTP which causes parkinsonism in man and primates. The MPTP-treated primate model is thus a useful model within which new drugs, including dopamine receptor agonists may be tested. Levodopa remains the mainstay of successful pharmacotherapy in the treatment of parkinson's disease. However the last decades have taught us that levodopa treatment with time produces problems of dyskinesias and unpredictable motor fluctuations. Hence alternate pharmacotherapy is sought to supplement levodopa or possibly to circumvent its necessity. (Abbreviation abstract) / Andrew Chakane 2019

Previous controlled studies have shown that severe daytime restriction of dietary protein improves the efficacy of L-dopa and reduces response fluctuations in some Parkinson's disease in-patients. The main purpose of the present study was to investigate the nutritional adequacy of the restricted protein diet. Other objectives were to assess the patients' acceptance of the diet and to identify the practical difficulties encountered in following the diet at home. The effect of the restricted protein diet on the subjects' response to levodopa was also examined. Subjects were 11 free-living, otherwise healthy Parkinson's disease patients who suffered from unpredictable response fluctuations to Sinemet (L-dopa containing medicine). This condition is also described as the "on-off" phenomenon. They were counselled to consume a daytime restricted protein diet for 6 weeks (mean ± s.d. protein intake before evening meal 12 ± 2 g for females and 14 ± 3 g for males). Food intake was unrestricted from dinner until bedtime, and subjects were encouraged to consume nutrient-dense foods during this period. The subjects were required to complete a series of three 6-day food records and "on-off" charts (pre-diet, diet week 2, diet week 6). The "on-off" charts indicated the daily number of hours spent in the "on" state (when medication is effective and parkinsonian symptoms are controlled) and in the "off" state (when medication is not effective and symptoms are not well controlled). Hemoglobin, plasma albumin, prealbumin and ferritin were measured before and after the 6-week diet period. Subjective evaluation questionnaires were completed by all participants and their spouses or caregivers. Results from dietary record analysis showed that the restricted protein diet was associated with significant decreases in total intakes of protein, calcium, iron, magnesium, phosphorus, niacin, riboflavin, vitamin B6 and pantothenate, in comparison to "usual" intakes. Intake of energy, carbohydrates, lipids, potassium, thiamin, folacin, and vitamins A, C and B12 did not change significantly. While on the restricted protein diet, only calcium intake was substantially less than the RNI. Biochemical measures of nutritional status were not significantly reduced. Mean body weight tended to decrease (p=.054) over the first 2 weeks and then stabilized until the end of the study period. The results of the "on-off" charts showed that three of the eleven subjects significantly increased their daily time "on" while on the restricted protein diet. Subjectively, six individuals noted an improvement in daytime mobility and indicated that they would maintain the diet for an indefinite period of time. Problems identified by the subjects included hunger prior-'to the evening meal and a lack of variety in food choices. These results show that otherwise healthy and motivated patients with Parkinson's disease can maintain an adequate intake of energy, protein, and most nutrients while on the daytime restricted protein diet. The diet appeared to be relatively well tolerated by patients who obtained a subjective benefit. It is suggested that in patients whose regular diets are marginally adequate, the restricted protein diet might compromise nutrient intakes. Counselling by a registered dietitian is recommended for all patients who undertake this type of diet. / Land and Food Systems, Faculty of / Graduate

初級運動皮質直接負責運動控制。大量關於帕金森式癥(PD)的有效治療手段的研究已經證明，初級運動皮質在病理情況下的功能改變，直接與患者運動障礙相關。本論文的研究重點在於探索初級運動皮質在深部腦刺激治療帕金森氏症的運動障礙的過程中發揮的作用及其與運動學習功能障礙的聯繫。 / 丘腦底核深部腦刺激(STN-DBS) 已被廣泛應用於治療帕金森式症。雖然該項治療手段能顯著地改善患者的運動功能障礙，但其確切的治療機制仍未明確。理論上來說，丘腦底核深部腦刺激能夠直接啟動丘腦底核內部和其周圍很大範圍的神經組織，包括丘腦底核內部本身的神經元胞體，以及與其相連接的輸入輸出核團的神經元軸突。在丘腦底核眾多輸入核團之中，一個重要的神經輸入來自於初級運動皮質(MI)第五層的離皮質神經元(CxFn)，電刺激引起的逆行皮質啟動作用被提出，用於解釋丘腦底核深部腦刺激的治療機制。 / 為了研究逆行皮質啟動效應究竟如何在丘腦底核深部腦刺激的過程之中帶來治療效果，我們採用多通道神經電生理信號記錄系統在自由活動的單側帕金森大鼠的初級運動皮質進行鋒電位元和局部場電位元信號的記錄。實驗結果證明，當對丘腦底核進行高頻電刺激，在運動皮質第五層的離皮質神經元能成功記錄到保持固定延時的逆行鋒電位。由於增加刺激頻率會引起逆行鋒電位被成功記錄到的百分比下降，因此當深部腦刺激的頻率選擇在125Hz時，逆行鋒電位的放電頻率達到最高，而此刺激頻率正好與行為學實驗中帶來最佳治療效果的刺激頻率一致。於此同時，逆行皮質啟動作用還伴隨著初級運動皮質離皮質神經元的自發放電頻率增加、同步性爆發式放電減少等電生理信號特點。場電位分析的結果進一步表明，丘腦底核深部腦刺激減弱了病理情況下出現的beta波頻譜能量增高以及鋒電位-場電位相干性增強。更重要的是，我們發現只有逆行鋒電位被成功誘發，離皮質神經元的發放電機率才能被調節。這點有力地表明由電刺激隨機誘發的逆行鋒電位傳導至初級運動皮質，直接幹預並抑制了離皮質神經元在病理情況下的同步性爆發式放電活動，從而緩解了帕金森氏症的運動障礙。 / 另外，初級運動皮質並不僅僅是一個靜態的運動控制中樞，更為重要的功能在於它參與著與運動學習和運動記憶相關的動態資訊編碼。帕金森氏症患者普遍存在皮質可塑性減弱以及運動技能學習障礙。由於初級運動皮質分層結構的存在，層內神經元之間的突觸連接為神經可塑性提供了很好的結構基礎。因此，我們在初級運動皮質誘發在體長時程增強(LTP)，旨在研究與運動技能學習相關的皮質神經可塑性的動態變化過程，以及探索中腦多巴胺能投射系統對皮質神經可塑性的影響。 / 一方面，我們採用間斷性高頻刺激誘發在體長時程增強，證實六羥多巴損毀後皮質的長時程增強水準顯著下降。另一方面，我們設計前肢抓食的行為學範式用來評價動物在運動技能學習的不同階段皮質可塑性發生的動態變化。實驗結果表明，直接損毀皮質的多巴胺能輸入，模型組大鼠與假實驗組大鼠的行為表現在初期的技能獲取階段並無明顯差異，而只在後期的技能鞏固階段模型組大鼠表現出技能鞏固障礙。更為有趣的是，兩組行為學變化趨勢與各自的在體長時程增強的變化趨勢有很高的一致性。本研究表明多巴胺對初級運動皮質的支配在運動記憶的鞏固過程中起著關鍵作用。在帕金森氏症的病理情況下，多巴胺耗竭將影響皮質的突觸可塑性，從而造成帕金森患者在運動技能的鞏固階段表現出障礙。 / The primary motor cortex (MI) controls movement directly, but is an under-investigated brain region in the pathogenesis and treatment of Parkinsonian motor disability, when compared with the basal ganglia circuitry. In this study, the roles of MI in underlying the therapeutic action of surgical deep brain stimulation and motor learning impairment were investigated. / Deep brain stimulation of the subthalamic nucleus (STN-DBS) is now a recognized therapeutic option for Parkinson’s disease (PD). Although this surgical strategy provides behavioral benefits remarkably, its exact mechanism is still a matter of controversy. In principle, STN-DBS can directly activate a wide range of neuronal elements within the STN and surrounding areas. As the corticofugal neurons (CxFn) in the layer V motor cortex provide a major input to the STN, we hypothesized that the stimulation evoked antidromic cortical activation is involved in the therapeutic mechanism of STN-DBS. In the first series of experiments, we performed simultaneous recordings of multi-unit neuronal activities and local field potentials (LFPs) in MI in freely moving hemi-parkinsonian rats. By identifying stimulation evoked antidromic spike, which occurred at a fixed, short latency, CxFn located in the layer V MI were identified. Increasing stimulation frequency also increased failure rate of activation, resulting in a peak frequency of stochastic antidromic spikes at 125Hz STN-DBS, which was correlated with the optimal therapeutic efficacy observed in behavioral tests. Meanwhile, this antidromic effect was accompanied by the rectification of pathological neuronal activities including increased spontaneous firing rate, reduced burst discharge and synchrony among the CxFn. Field potential analysis revealed that STN-DBS alleviated the dominance of pathological beta band oscillation and spike-field coherence in the MI. More importantly, it was found that the firing probability of CxFn could only be modified following the occurrence of antidromic spikes, suggesting that direct interference of stochastic antidromic spikes with pathological neuronal activities underlies the beneficial effect of STN-DBS. / The MI is not simply a static motor control structure. It also contains a dynamic substrate that participates in motor learning or stores motor memory. In PD patients, loss of cortical plasticity and impaired motor learning is a common feature. As the intrinsic horizontal neuronal connections in MI are a strong candidate of cellular correlate for activity-dependent plasticity, in the second series of experiments, we developed in vivo long-term potentiation (LTP) technique in the MI to investigate the dynamics of cortical plasticity during motor skill learning and the role of the innervation by mesocortical dopamine input. Local depletion of dopamine in the primary motor cortex resulted in reduced performance in the forelimb reaching for food learning task. Although the performance of the PD rats in the initial learning phase was comparable to that of the sham-operated group, as training continued, these animals exhibited deficit in consolidating the motor skill. These deficits closely paralleled the impairment in training-enhanced synaptic connections in layer V neurons, and the in vivo LTP of evoked field excitatory postsynaptic potentials induced by intermittent high frequency stimulation. In addition, progressive recruitment of task-specific neurons was suppressed. Our study therefore revealed that dopamine depletion confined to the MI could lead to impairment in cortical synaptic plasticity which may preferentially affect the consolidation, but not the acquisition, of motor skills. These findings shed light on the cellular mechanisms of motor skill learning and could explain the decreased ability of PD patients in learning new motor skills. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Li, Qian. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 168-190). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / CHAPTER 1 --- p.1 / General Introduction --- p.1 / Chapter 1.1 --- Anatomical organization of the basal ganglia --- p.1 / Chapter 1.1.1 --- Overview of the basal ganglia circuit --- p.1 / Chapter 1.1.2 --- Cortico-basal ganglia-cortical circuit --- p.1 / Chapter 1.1.2.1 --- Direct and indirect pathway --- p.2 / Chapter 1.1.2.2 --- Hyperdirect pathway --- p.2 / Chapter 1.1.2.3 --- The midbrain dopamine system --- p.2 / Chapter 1.2 --- Striatum --- p.3 / Chapter 1.2.1 --- Cell types in the striatum. --- p.3 / Chapter 1.2.2 --- The Cortico-striatal system --- p.4 / Chapter 1.3 --- Subthalamic Nucleus --- p.5 / Chapter 1.3.1 --- Neuronal property of the STN. --- p.5 / Chapter 1.3.2 --- Electrophysiological property of the STN --- p.6 / Chapter 1.3.3 --- Cortico-subthalamic system --- p.7 / Chapter 1.3.4 --- Functional significance of the cortico-subthalamic and corticostriatal system. --- p.8 / Chapter 1.4 --- Parkinson’s disease --- p.9 / Chapter 1.4.1 --- Pathogenesis of PD --- p.9 / Chapter 1.4.2 --- Genetic risk factors of PD --- p.10 / Chapter 1.4.3 --- Progressive motor symptoms of PD --- p.11 / Chapter 1.4.4 --- Non-motor symptoms of PD --- p.13 / Chapter 1.4.5 --- Pathological neuronal rhythms in the basal ganglia of PD. --- p.16 / Chapter 1.5 --- Experimental studies of PD. --- p.18 / Chapter 1.5.1 --- Animal modeling of PD. --- p.18 / Chapter 1.5.2 --- Motor deficits evaluation in rodent models of PD --- p.21 / Chapter 1.5.3 --- Non-motor symptoms evaluation in experimental models of PD --- p.24 / Chapter 1.6 --- Deep Brain Stimulation --- p.27 / Chapter 1.6.1 --- DBS in alleviating Parkinsonian motor symptoms --- p.28 / Chapter 1.6.2 --- DBS in alleviating Parkinsonian non-motor symptoms --- p.29 / Chapter 1.6.3 --- Investigation of the STN-DBS mechanism. --- p.31 / Chapter 1.6.3.1 --- Local inhibitory effect within the STN --- p.32 / Chapter 1.6.3.2 --- Excitatory effect at output nuclei --- p.33 / Chapter 1.6.3.3 --- The de-coupling of soma and axons at system level --- p.34 / Chapter 1.6.3.4 --- Effects of DBS on abnormal rate or pattern --- p.35 / Chapter 1.6.3.5 --- Antidromic propagation of DBS effect towards cortex --- p.37 / Chapter 1.7 --- Objective --- p.38 / Chapter 1.8 --- Figures --- p.41 / CHAPTER 2 --- p.47 / General Methods --- p.47 / Chapter 2.1 --- Animals --- p.47 / Chapter 2.2 --- Stereotaxic surgery --- p.47 / Chapter 2.2.1 --- Preoperative preparation --- p.47 / Chapter 2.2.2 --- Anesthesia and craniotomy --- p.48 / Chapter 2.2.3 --- Induction of hemi-Parkinsonian rat model --- p.48 / Chapter 2.2.4 --- Electrode implantation techniques. --- p.49 / Chapter 2.3 --- Behavioral assessment. --- p.50 / Chapter 2.3.1 --- Apomorphine-induced contralateral rotation. --- p.50 / Chapter 2.3.2 --- Open field test --- p.50 / Chapter 2.4 --- STN-DBS protocol --- p.50 / Chapter 2.5 --- Electrophysiological data acquisition --- p.51 / Chapter 2.6 --- Data analysis --- p.52 / Chapter 2.6.1 --- Statistical analysis of behavioral data --- p.52 / Chapter 2.6.2 --- Electrophysiological data --- p.52 / Chapter 2.6.2.1 --- Stimulation artifact removal --- p.52 / Chapter 2.6.2.2 --- Multi-unit spike sorting --- p.53 / Chapter 2.6.2.3 --- Electrophysiological identification of pyramidal neuron and interneuron. --- p.54 / Chapter 2.6.2.4 --- Identification of antidromic cortical activation --- p.54 / Chapter 2.6.2.5 --- Discharge pattern classification --- p.54 / Chapter 2.6.2.6 --- Synchrony level evaluation --- p.55 / Chapter 2.6.2.7 --- Oscillatory rhythm characterization --- p.55 / Chapter 2.6.2.8 --- Coherence Level Measurement --- p.56 / Chapter 2.7 --- Histological verification --- p.56 / Chapter 2.8 --- Figures --- p.58 / CHAPTER 3 --- p.60 / Alleviation of Parkinsonian Motor Symptoms during Deep Brain Stimulation in Hemi-Parkinsonian Rats --- p.60 / Chapter 3.1 --- Introduction --- p.60 / Chapter 3.2 --- Materials & Methods --- p.61 / Chapter 3.2.1 --- Animals --- p.61 / Chapter 3.2.2 --- Chemicals --- p.61 / Chapter 3.2.3 --- Equipment --- p.61 / Chapter 3.3 --- Results --- p.62 / Chapter 3.3.1 --- Time course of the Apomorphine induced rotation behavior --- p.62 / Chapter 3.3.2 --- Dose-dependence of the Apomorphine induced rotation --- p.62 / Chapter 3.3.3 --- Acute behavioral response to STN-DBS. --- p.63 / Chapter 3.3.4 --- The dependence of STN-DBS effect on stimulation paradigm. --- p.64 / Chapter 3.3.5 --- Acute effects of STN-DBS on APO induced rotation. --- p.64 / Chapter 3.3.6 --- Long-term effects of STN-DBS on APO induced rotation --- p.64 / Chapter 3.3.7 --- Histological confirmation of the stimulation electrodes localization --- p.65 / Chapter 3.3.8 --- Loss of DA neurons in the SNc --- p.65 / Chapter 3.3.9 --- Reductions of the DA axon terminals in the striatum --- p.65 / Chapter 3.3.10 --- Chronic STN-DBS failed to rescue nigrostsriatal and striatal DA --- p.66 / Chapter 3.4 --- Discussion --- p.66 / Chapter 3.4.1 --- Neurotoxic mechanism of 6-OHDA --- p.66 / Chapter 3.4.2 --- Time course of dopamine degeneration induced by 6-OHDA --- p.66 / Chapter 3.4.3 --- Failure in observing worsened motor symptoms during low frequency STN-DBS. --- p.67 / Chapter 3.4.4 --- Experimental DBS based on rat model: does it mimic human case? --- p.67 / Chapter 3.4.5 --- Technical issues about STN-DBS --- p.69 / Chapter 3.5 --- Figures --- p.72 / CHAPTER 4 --- p.82 / Direct involvement of the Corticofugal Neurons in Motor Cortex during Therapeutic Deep Brain Stimulation --- p.82 / Chapter 4.1 --- Introduction --- p.82 / Chapter 4.2 --- Materials --- p.83 / Chapter 4.2.1 --- Animals --- p.83 / Chapter 4.2.2 --- Chemicals --- p.83 / Chapter 4.2.3 --- Equipment --- p.83 / Chapter 4.3 --- Results --- p.84 / Chapter 4.3.1 --- Identification of CxFn based on antidromic effect --- p.84 / Chapter 4.3.2 --- Antidromic spikes frequency correlates with therapeutic effect of STN-DBS. --- p.84 / Chapter 4.3.3 --- Pathological changes of neuronal firing rate in MI --- p.85 / Chapter 4.3.4 --- Only high frequency STN-DBS normalizes neuronal firing rate in MI --- p.86 / Chapter 4.3.5 --- Pathological changes of neuronal discharge pattern in MI --- p.88 / Chapter 4.3.6 --- Pathological synchrony of MI neuronal population, especially during burst discharge --- p.89 / Chapter 4.3.7 --- High frequency STN-DBS successfully suppresses synchronized burst discharge in MI --- p.89 / Chapter 4.3.8 --- Pathological β-band oscillatory activity in MI-LFPs induced by 6-OHDA lesion --- p.90 / Chapter 4.3.9 --- High frequency STN-DBS alleviates the β-band oscillation in MI-LFPs --- p.90 / Chapter 4.3.10 --- Synchronized bursting discharge correlates with oscillatory activity --- p.91 / Chapter 4.3.11 --- Pathological increased spike-LFP coherence level induced by 6-OHDA lesion --- p.92 / Chapter 4.3.12 --- High frequency STN-DBS modulated the spike-LFP coherence properties --- p.92 / Chapter 4.3.13 --- Antidromic spikes directly modulate the firing probability of CxFn --- p.93 / Chapter 4.3.14 --- Antidromic spikes modulate the firing probability of INs and non-CxFn nearby. --- p.94 / Chapter 4.3.15 --- The efficiency of antidromic cortical modulation depends on DBS frequency --- p.94 / Chapter 4.3.16 --- Orthodromic vs. antidromic effect: which one is responsible for the beneficial effect of DBS? --- p.95 / Chapter 4.3.17 --- Histology --- p.96 / Chapter 4.4 --- Discussion --- p.96 / Chapter 4.4.1 --- Origin of pathogenic rhythm in basal ganglia circuit --- p.96 / Chapter 4.4.2 --- Suppression of oscillatory synchronization equals to therapeutic effects of DBS? --- p.97 / Chapter 4.4.3 --- Beneficial effect of DBS corresponds to the topographic distribution of cortico-subthalamic projection. --- p.98 / Chapter 4.4.4 --- What is the reason for a stochastic pattern of antidromic activation effect? --- p.99 / Chapter 4.4.5 --- Desynchronization of pathological oscillatory rhythm by antidromic activation --- p.100 / Chapter 4.4.6 --- Antidromic vs. orthodromic: which is the cause of the beneficial effects of DBS? --- p.101 / Chapter 4.4.7 --- Wide propagation of antidromic effect by cortical horizontal circuits --- p.102 / Chapter 4.4.8 --- Significance of antidromic cortical activation in during STN-DBS --- p.102 / Chapter 4.4.9 --- Implication of antidromic activation effect on pathogenesis and treatment of PD --- p.104 / Chapter 4.5 --- Figures --- p.105 / CHAPTER 5 --- p.132 / Impaired Synaptic Plasticity in the Primary Motor Cortex after Dopamine Depletion: Potential Role in Motor Memory Consolidation --- p.132 / Chapter 5.1 --- Introduction --- p.132 / Chapter 5.1.1 --- Characteristics of motor learning --- p.132 / Chapter 5.1.2 --- Motor learning related cortical plasticity. --- p.133 / Chapter 5.1.3 --- Dopaminergic signals in the primary motor cortex --- p.134 / Chapter 5.1.4 --- Impaired cortical plasticity in PD --- p.135 / Chapter 5.1.5 --- Objective --- p.136 / Chapter 5.2 --- Materials --- p.136 / Chapter 5.2.1 --- Animals --- p.136 / Chapter 5.2.2 --- Chemicals --- p.136 / Chapter 5.2.3 --- Equipment --- p.136 / Chapter 5.3 --- Methods --- p.136 / Chapter 5.3.1 --- Functional mapping of the forelimb territory in MI --- p.136 / Chapter 5.3.2 --- Stereotaxic surgery --- p.137 / Chapter 5.3.3 --- Forelimb-reaching Task. --- p.137 / Chapter 5.3.4 --- In-vivo LTP Induction. --- p.138 / Chapter 5.4 --- Results --- p.139 / Chapter 5.4.1 --- Functional mapping of rat forelimb territory. --- p.139 / Chapter 5.4.2 --- Morphologies of evoked field potential response --- p.139 / Chapter 5.4.3 --- LTP of the early, monosynaptic plasticity within horizontal layer V MI --- p.140 / Chapter 5.4.4 --- LTP of the late, polysynaptic plasticity within horizontal layer V MI --- p.140 / Chapter 5.4.5 --- Impaired synaptic plasticity in MI after dopamine depletion --- p.140 / Chapter 5.4.6 --- Learning curve of forelimb-reaching task --- p.140 / Chapter 5.4.7 --- Physiologically enhanced cortical plasticity during motor learning --- p.141 / Chapter 5.4.8 --- Dynamic modulation of cortical neuronal activities during motor skill learning. --- p.142 / Chapter 5.4.9 --- Statistical analysis of ‘task related’ neuron’s modulation pattern. --- p.143 / Chapter 5.4.10 --- Loss of dopamine modulation in the MI --- p.144 / Chapter 5.5 --- Discussion --- p.144 / Chapter 5.5.1 --- Distinguishing between monosynaptic and polysynaptic transmission --- p.144 / Chapter 5.5.2 --- Artificially vs physiologically induced cortical plasticity. --- p.145 / Chapter 5.5.3 --- Cortical synaptic plasticity interprets motor learning dynamics --- p.146 / Chapter 5.5.4 --- Balance between neuronal recruitment and withdrawal in the consolidation stage --- p.147 / Chapter 5.5.5 --- Dopamine’s involvement in mediating the cortical synaptic plasticity. --- p.148 / Chapter 5.6 --- Figures --- p.150 / Conclusion --- p.162 / Abbreviations --- p.165 / References --- p.168

by Wai Yuen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 123-157). / Abstracts in English and Chinese. / Acknowledegment --- p.iv / Abstract --- p.v / List of Abbreviations --- p.ix / Chapter CHAPTER ONE: --- INTRODUCTION / Chapter 1.1 --- Parkinson's Disease (PD) --- p.1 / Chapter 1.1.1 --- Epidemiology --- p.1 / Chapter 1.1.2 --- Neuropathology --- p.2 / Chapter 1.1.3 --- Clinical Symptoms --- p.3 / Chapter 1.1.4 --- Treatment --- p.6 / Chapter 1.2 --- Proposed Mechanisms of Neurodegeneration in PD --- p.11 / Chapter 1.2.1 --- Oxidative Stress --- p.11 / Chapter 1.2.2 --- Mitochondrial Dysfunction --- p.13 / Chapter 1.2.3 --- Genetic Factors --- p.15 / Chapter 1.2.4 --- Environmental Factors --- p.17 / Chapter 1.2.5 --- Ageing --- p.20 / Chapter 1.3 --- "1-Methy-4-Phenyl-1,2,3,6-Tetrahydropyridine (MPTP) as a PD Model" --- p.22 / Chapter 1.3.1 --- Discovery of MPTP --- p.22 / Chapter 1.3.2 --- The Mechanisms of MPTP-induced Neurotoxicity --- p.23 / Chapter 1.4 --- Antioxidants in the Central Nervous System --- p.26 / Chapter 1.4.1 --- Superoxide Dismutase --- p.26 / Chapter 1.4.2 --- Glutathione --- p.27 / Chapter 1.5 --- Metallothioneins (MTs) --- p.29 / Chapter 1.5.1 --- Characteristics of MTs --- p.29 / Chapter 1.5.2 --- Functions of Astrocytes --- p.31 / Chapter 1.6 --- Astrocytes --- p.34 / Chapter 1.6.1 --- Characteristics of Astrocytes --- p.34 / Chapter 1.6.2 --- Functions of Astrocytes --- p.35 / Chapter 1.6.3 --- Role of Astrocytes in Parkinson's Disease --- p.39 / Chapter 1.7 --- Aim of Project --- p.41 / Chapter CHAPTER TWO: --- MATERIALS AND METHODS / Chapter 2.1 --- In Vitro Study --- p.44 / Chapter 2.1.1 --- Astrocyte Cultures --- p.44 / Chapter 2.1.2 --- Treatment Regimen --- p.46 / Chapter 2.1.2.1 --- 1 -methyl-4-phenyl-pyridinium (MPP+) Treatment --- p.46 / Chapter 2.1.2.2 --- Induction of Metallothioneins (MTs) and Glutathione (GSH) --- p.46 / Chapter 2.1.2.2.1 --- Northern Blot Analysis --- p.47 / Chapter 2.1.2.2.2 --- Immunocytochemical Staining for MTs --- p.48 / Chapter 2.1.2.2.3 --- GSH Assay --- p.49 / Chapter 2.1.2.3 --- Iron Chelation --- p.51 / Chapter 2.1.2.4 --- Combined Pretreatment --- p.51 / Chapter 2.1.3 --- Lactate Dehydrogenase (LDH) Assay --- p.51 / Chapter 2.1.4 --- "3,(4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) Assay" --- p.53 / Chapter 2.1.5 --- Reactive Oxygen Species (ROS) Assay --- p.55 / Chapter 2.1.6 --- Protein Assay --- p.56 / Chapter 2.1.7 --- Statistics --- p.57 / Chapter 2.2 --- In Vivo Study --- p.57 / Chapter 2.2.1 --- "Administration of 1 -methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)" --- p.57 / Chapter 2.2.2 --- Tyrosine Hydroxylase (TH) Immunocytochemical Staining --- p.58 / Chapter 2.2.3 --- DAT Receptor Binding Assay --- p.59 / Chapter 2.2.4 --- Dopamine (DA) and DA metabolites - High Performance Liquid Chromatography (HPLC) --- p.60 / Chapter 2.2.5 --- Statistics --- p.61 / Chapter CHAPTER THREE: --- RESULTS / Chapter 3.1 --- In Vitro Study --- p.62 / Chapter 3.1.1. --- Induction of Metallothioneins (MTs) in Astrocytes with Zinc Sulfate (ZnS04) --- p.62 / Chapter 3.1.1.1 --- Immunocytochemical changes --- p.62 / Chapter 3.1.1.2 --- Northern Blot Analysis --- p.62 / Chapter 3.1.1.3 --- The Effects of ZnSO4 Pretreatment on 1 -methyl-4-phenyl- pyridinium (MPP+)-treated Astrocytes --- p.63 / Chapter 3.1.1.3.1 --- Lactate Dehydrogenase (LDH) Activities --- p.63 / Chapter 3.1.1.3.2 --- "3,(4,5-dimethylthiazol-2-yl)2,5-diphenyl- tetrazolium bromide (MTT) Activities" --- p.67 / Chapter 3.1.1.3.3 --- Reactive Oxygen Species (ROS) Production --- p.71 / Chapter 3.1.2 --- The Effects of NAc Pretreatment on MPP+-treated Astrocytes --- p.75 / Chapter 3.1.2.1 --- Glutathione (GSH) levels --- p.75 / Chapter 3.1.2.2 --- LDH Activities --- p.77 / Chapter 3.1.2.3 --- MTT Activities --- p.80 / Chapter 3.1.2.4 --- ROS Production --- p.83 / Chapter 3.1.3 --- The Effects of Deferoxamine on MPP+-treated Astrocytes --- p.87 / Chapter 3.1.3.1 --- LDH Activities --- p.87 / Chapter 3.1.3.2 --- ROS Production --- p.89 / Chapter 3.1.4 --- The Effects of ZnSO4 and NAc Combined Treatment on MPP+-treated Astrocytes --- p.92 / Chapter 3.1.4.1 --- LDH Activities --- p.92 / Chapter 3.1.4.2 --- ROS Production --- p.95 / Chapter 3.2 --- "Effects of 1 -methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on MT-I, -II Knock-out Mice" --- p.99 / Chapter 3.2.1 --- The Effects of MPTP on Substantia Nigral (SN) Cell Loss --- p.99 / Chapter 3.2.2 --- The Effects of MPTP on Striatal (ST) and SN Dopamine Transporter (DAT) Binding --- p.99 / Chapter 3.2.3 --- The Effects of MPTP on ST Dopamine (DA) Metabolites --- p.100 / Chapter CHAPTER FOUR: --- DISCUSSION AND CONCLUSION --- p.102 / REFERENCES --- p.123