Neurodegenerative diseases are hallmarked by protein inclusions and cell loss in disease-related brain regions, but the molecular mechanisms that lead to the pathological and symptomatic hallmarks... Show moreNeurodegenerative diseases are hallmarked by protein inclusions and cell loss in disease-related brain regions, but the molecular mechanisms that lead to the pathological and symptomatic hallmarks of neurodegeneration are still not fully understood. In this thesis, we make use of bioinformatics approaches to analyze a high-resolution spatial gene expression atlas of the healthy human brain generated by the Allen Institute of Brain Science. Spatial transcriptomics allows examining the molecular and functional organization of the human brain and can be combined with neuroimaging data to identify brain regions and anatomical structures that are vulnerable to cell loss in neurodegenerative diseases. By combining both data modalities, we examined healthy molecular functions in brain regions associated with disease vulnerability based on neuroimaging features, namely gray matter loss within brain networks in individuals with Parkinson’s disease, Huntington’s disease, and individuals at risk of schizophrenia. With this thesis, we have shown that by applying data-driven computational methods we can explore the whole genome and find gene expression patterns informative of regional brain vulnerability in neurodegenerative diseases. Our methods can similarly be applied to unravel the molecular mechanisms in other neurodegenerative diseases, and potentially even reveal shared mechanisms between neurological disorders. Show less
Fungi are a very successful species and are distributed worldwide. However, the presence of fungi is not always desired. Filamentous fungi can grow on living or dead organic material and even... Show moreFungi are a very successful species and are distributed worldwide. However, the presence of fungi is not always desired. Filamentous fungi can grow on living or dead organic material and even inside the host. Current methods to prevent fungal growth are insufficient, causing fatality after fungal infections or loss of crops. The cell wall of a fungus is an intriguing component. It protects the cell from the harsh environment and determines the shape of the cell. Hence the cell wall is an essential component to the cell and provides an attractive target for antifungals. Additionally, the cell wall contains components only found in fungi, and the target is a desirable target as it is exposed on the outside of the cell. Currently, little is known about the cell wall of filamentous fungi. In order to design new or improved antifungal compounds, a better understanding of the fungal cell wall and of its adaptation to various conditions is required. In this thesis, we have used Aspergillus niger as a model filamentous fungus to study the biosynthesis of the fungal cell wall. The cell wall is a highly dynamic structure and able to adapt to various changes, either developmental (e.g. mating, growth, budding, branching and sporulation), environmental (e.g. heat, pH, osmolarity, chemical compounds), or genetic (e.g. mutations in cell-wall related genes). In chapter 1 an overview is presented of the current state of knowledge about the fungal cell wall. The architecture, biosynthesis and the remodeling are discussed in this chapter. The response of our model fungus A. niger to chemical induced cell wall stress is described in chapter 2. The fluorescent brightener Calcofluor White (CFW) was used to induce cell wall stress. We show that A. niger, like Saccharomyces cerevisiae, responds to cell wall stress by an increase of chitin deposition in the cell walls. This increase in chitin, a structural cell wall polymer, was accompanied by an increased transcription level of gfaA. It was also shown that this mechanism is not only limited to A. niger but is also observed in other filamentous fungi like the plant pathogenic fungus Fusarium oxysporum and the food spoilage fungus Penicillium chrysogenum. It is further shown that gfaA is an essential gene and the deletion strain can be rescued by addition of glucosamine. In chapter 3, a family of five 1,3-__-D-glucan synthase encoding genes is described. The expression of these genes during various types of cell wall stress was monitored and it was found that the expression of agsA and agsE was induced. The induction of an 1,3-__-D-glucan synthase encoding gene after cell wall stress was also observed in P. chrysogenum. The deletion of agsA led to an increased sensitivity towards CFW. While in chapter 2 and 3 changes in expression levels of genes encoding proteins involved in cell wall biosynthesis are described, the mechanism behind the induction of cell wall stress responsive genes is described in chapter 4. A promoter deletion study combined with an in silico analysis indicated that the induction of agsA in response to cell wall stress is dependent on a putative Rlm1p binding site in its promoter. Therefore a gene, named rlmA encoding for a MADS-box transcription factor was isolated from A. niger after database searches. The role of this gene in the induction of agsA and gfaA after CFW stress was investigated. A deletion of the rlmA gene was constructed and this resulted in an increased sensitivity towards cell wall disturbing compounds. In S. cerevisiae an important part of the response towards cell wall threatening conditions is the up-regulation of GPI-anchored cell wall proteins. In chapter 5 the isolation and characterisation of an HF-extractable cell wall protein from A. niger, named CwpA, is described. It was shown by simple fractionation experiments that the protein was mainly present in the cell wall fraction. Deletion of cwpA resulted in an increased sensitivity towards CFW suggesting a structural role for CwpA. Chapter 6 describes a novel method for the identification of cell wall mutants. The mutants are first selected based on their compensatory reaction (induction of agsA) and subsequenly subjected to various secondary screens, to confirm an altered cell wall integrity. Four out of 240 mutants with induced agsA expression levels, named miaA-D, were selected for complementation. All four mutants were complemented by cosmids. Further subcloning experiments are underway to identify the mutated genes. In chapter 7 a GFP-based reporter system is described. The system allows the rapid screening of compounds to see if they trigger the cell wall integrity pathway and thereby induce the PagsA(-H2B)-GFP reporter. The method has been evaluated towards various putative antifungal compounds and is a promising tool for the identification of new cell wall related antifungal compounds. In conclusion, this thesis provides evidence for the existence of a cell wall remodeling mechanism in filamentous fungi and in particular A. niger. Also, signal transduction pathway components were identified by which cell wall weakening is sensed and transduced into a transcriptional response. Additionally, a cell wall stress reporter system was developed to identify new cell wall related antifungal targets and to identify cell wall related antifungal compounds. Show less
With the ever-increasing life expectancies of people, the prevalence of aging-related diseases is also increasing. We studied a unique cohort of people; offspring of nonagenarian siblings with the... Show moreWith the ever-increasing life expectancies of people, the prevalence of aging-related diseases is also increasing. We studied a unique cohort of people; offspring of nonagenarian siblings with the propensity for longevity were also recruited and compared to their partners, representing the general population. The offspring (~60 year old) already show lower prevalence of cardiovascular disease and diabetes. In the thesis __Cellular stress in vitro and longevity on vivo__ it is reported how cells (dermal fibroblasts) derived from these offspring were compared with cells from their partners. It was shown that they react differenly in vitro under both non stressed and under conditions of oxidative stress. Future research is warranted to further elucidate the genes involved in these differences. Show less
In this thesis, determinants, risk and protective factors of parental reactions to childhood cancer are described and research areas that are understudied until now have been identified. Chapter 2... Show moreIn this thesis, determinants, risk and protective factors of parental reactions to childhood cancer are described and research areas that are understudied until now have been identified. Chapter 2 contains a review study on stress and adaptation in parents of pediatric cancer patients. Chapter 3 describes the results of a multicenter study among parents of children with cancer with the aim to evaluate the psychometric qualities of the Dutch version of a disease-related instrument measuring parental stress. Chapter 4 is a review article on parental stress and adaptation among parents of children undergoing stem cell transplantation (SCT). Chapter 5 contains the results of a longitudinal study on child- and parent reported health related quality of life and parenting stress in parents of children undergoing SCT. In Chapter 6, the results of a cross-sectional study on parental stress and perceptions of child vulnerability in parents of children who underwent SCT either 5 or 10 years ago are reported. In Chapter 7, cognitive problems, behavior problems and health related quality of life of children with LCH are described. Show less
When a child is often scolded or threatened by his parents (emotional abuse) and /or when a child is structurally ignored or isolated by his parents (emotional neglect) we call this childhood... Show moreWhen a child is often scolded or threatened by his parents (emotional abuse) and /or when a child is structurally ignored or isolated by his parents (emotional neglect) we call this childhood emotional maltreatment (CEM). CEM is the most common form of child abuse, however, CEM is also the most hidden, underreported and least studied form of child abuse. An important reason for this may be because that the consequences of CEM are underestimated (e.g. __Sticks and Stones may break bones, but words will never hurt me__). However, this thesis shows that CEM is related with a persistent negative impact on cognition and the brain. We discovered that individuals that report CEM show differential structure and function of a brain area (the medial prefrontal cortex) that is crucial for role in responding to stress and thinking about yourself. Individuals with CEM also showed more activity in an area that signals threat (the amygdala) which may represent a persistent vigilance towards the detection of threat from others. These brain changes may underlie our other findings that individuals with CEM think more negatively about themselves and others. Negative thoughts can evoke negative thoughts and in new situations, which reinforces more negative memories. Due to this process, emotionally abused individuals may be more vulnerable to develop a depressive and/or anxiety disorder. Our findings warrant scientific and policital investments to increase societal awareness about the detrimental impact of CEM on cognition and the brain. Increased societal knowledge will hopefully lead to better awareness, reports, and subsequent interventions for individuals with CEM. Show less
In modern society, circadian rhythms and sleep are often disturbed, which may negatively affect health. This thesis examines these associations and focuses on the basic functioning of sleep and the... Show moreIn modern society, circadian rhythms and sleep are often disturbed, which may negatively affect health. This thesis examines these associations and focuses on the basic functioning of sleep and the circadian system in mice and in humans. Circadian rhythms are orchestrated by ~20,000 neurons in the central clock in the suprachiasmatic nuclei (SCN) in the brain. In mice, a complete abolishment of central clock-driven rhythms resulted in obesity and severe hepatic insulin resistance. An attenuation of rhythms resulted in decreased muscle strength, osteoporosis-like bone changes and transient changes in the immune system. In humans, short sleeping obese individuals with a preference for evening activities ("evening chronotypes") had increased cardiovascular risk factors. Their neurocognitive function was often impaired and could be improved with sleep extension. Insufficient sleep was also associated with an increased risk for osteopenia and sarcopenia. Taken together, disrupted circadian rhythms and insufficient sleep associate with a spectrum of unfavorable health outcomes. Studies described in the thesis provide insight in potential strategies to improve rhythms and sleep: by appropriately timed behavior (active behavior during the active phase; rest during the rest phase), light exposure (light during the subjective day; darkness at night) as well as caffeine intake. Show less
This book contains two main messages. First, an attempt is made to explain the diverse beneficial findings on cognition and mental health in the literature of meditation practices by the factor of... Show moreThis book contains two main messages. First, an attempt is made to explain the diverse beneficial findings on cognition and mental health in the literature of meditation practices by the factor of breathing. In the respiratory vagal nerve stimulation model of contemplative practices (rVNS) specific respiratory patterns lead to changes in autonomic nervous system functioning that in turn produce changes in the central nervous system, which can be observed in a healthier cognitive and emotional balance. Second, there are two empirical chapters that show null-results on cognition with meditative movement (Tai Chi Chuan) and breathing interventions. The possible reasons for these lack of results are extensively discussed in this dissertation and put into a wider perspective within the scientific field. Show less
What we collectively call “stress” is how we experience our body’s reaction to a stressor. This response is aimed to deal with the current stressor and to prepare for recurrences in the future. The... Show moreWhat we collectively call “stress” is how we experience our body’s reaction to a stressor. This response is aimed to deal with the current stressor and to prepare for recurrences in the future. The stress response is for an important part dependent on glucocorticoid hormones. By and large, the acute response to glucocorticoids is beneficial, but chronic exposure often becomes maladaptive. To improve prevention and treatment of disorders we can develop due to stress, it is important to better understand the effects and working mechanisms of glucocorticoids. While we already possess extensive knowledge regarding glucocorticoids and glucocorticoid receptor signaling, we introduced and studied five “aspects of context”, which we felt address important current misconceptions or gaps of knowledge. Corticosterone was at the center of all the studies we performed, yet the eventual outcome of glucocorticoid receptor activation differed extensively in all experiments. Thus, the context in which corticosterone exerts its effects matters, and it is to researcher to be aware of this when designing new studies and interpreting available data. Whilst our research merely addressed some specific processes, the lessons learned from these experiments can be applied much broader to the biology of glucocorticoid signaling and other nuclear family members. Show less
In this thesis I aimed to explore further finesses in the cellular dynamics of the two corticosteroid receptors, the MR and the GR, in both their membrane-associated and their nuclear... Show moreIn this thesis I aimed to explore further finesses in the cellular dynamics of the two corticosteroid receptors, the MR and the GR, in both their membrane-associated and their nuclear subpopulations. Amongst others I quantified the dynamics of the receptors at the membrane (only MR) and at the chromatin Show less
From an evolutionary perspective, stress is an adaptive system that is necessary togenerate appropriate responses to stochastic and unpredictable events, and copeaccordingly with the environment.... Show moreFrom an evolutionary perspective, stress is an adaptive system that is necessary togenerate appropriate responses to stochastic and unpredictable events, and copeaccordingly with the environment. The physiological response to stress has beenremarkably conserved in vertebrate evolution. However, the threats to ourinternal “equilibrium” have changed between our ancestral environments and ourcurrent modern societies, and the demands for survival have evolved. Theglucocorticoid receptor (GR) is a timeless component of stress adaptation, as it is atthe intersection between the environmental stressors (i.e., physical, or psychosocial)and the genome. Therefore, the GR represents a valuable therapeutic target instress- and glucocorticoid-related disorders. This thesis provides new insightsinto the molecular mechanisms underlying GR signaling in metabolic diseases andbrain function and highlights the promise and importance of selectivity in novel GRtargeting treatments. Show less
An adverse early life event is considered a risk factor for stress-related psychiatric disorders in genetically predisposed individuals, probably because of its lasting effect on susceptibility to... Show moreAn adverse early life event is considered a risk factor for stress-related psychiatric disorders in genetically predisposed individuals, probably because of its lasting effect on susceptibility to stress. The objective of this thesis research was to examine in the mouse CD1 strain the immediate and permanent effects of an adverse early experience on the neuroendocrine stress system. For this purpose the hypothalamic-pituitary-adrenal (HPA) axis was examined of mouse pups that were refrained from maternal care, a laboratory model for neglect mimicking aspects of abuse. The data show that the infants__ stress response system readily adapts to daily repeated 8 hours of maternal separation, but that it continues to respond to a novelty stressor. The rapid adaptation to repeated maternal absence seems rather due to the ability to predict return of the mother than to adjust metabolism to episodic food deprivation. If maternal separation was extended to a single episode of 24 hours the immediate outcome was more profound but transient, although subtle effects on stress reactions and cognitive performance did persist. The findings demonstrate the amazing plasticity of the newborn brain and provide a basis to study the mechanistic underpinning of vulnerability or resilience to psychopathology. Show less
Currently, the raising awareness of the role of glucocorticoids in the onset of numerous (neuro)-pathologies constitutes the increasing necessity of understanding the mechanisms of action of... Show moreCurrently, the raising awareness of the role of glucocorticoids in the onset of numerous (neuro)-pathologies constitutes the increasing necessity of understanding the mechanisms of action of glucocorticoids in bodily processes and brain functioning. Glucocorticoids mediate their effects by binding to intracellular receptors which act as transcription factors. A remarkable and yet unexplained phenomenon described more than two decades ago, is the cell-specific effects glucocorticoids bring about on gene expression in brain. For example, while glucocorticoids suppress corticotrophin-releasing hormone (CRH) synthesis in the hypothalamus, production of CRH in the central nucleus of the amygdala (CeA) is stimulated by increased hormone levels. Inasmuch as the neuroanatomical distribution of the corticosteroid receptors does not satisfactorily explain these effects, it is of interest to decipher the role of recently discovered coregu lator proteins that modulate the direction and the magnitude of steroid receptor-driven transcription. Therefore, in the current thesis the expression and function of central coregulators was studied: the coactivators SRC1a and SRC1e along with the corepressors N-CoR and SMRT were found to be expressed in brain and involved in regulation of CRH gene expression. Finally, a method that allows detection of coregulator recruitment by steroid receptors in brain tissue was developed. Show less
The main goal of the present thesis was to study the effects of stress and stress hormones on the retrieval of emotional memories in healthy humans. In addition, we were interested in the effects... Show moreThe main goal of the present thesis was to study the effects of stress and stress hormones on the retrieval of emotional memories in healthy humans. In addition, we were interested in the effects of stress hormones on post-retrieval processes like reconsolidation. That is, are there only acute and temporary effects of stress hormones on memory retrieval, or are there also long-term effects? Studying effects of stress hormones can be done in two ways; either by (experimentally) inducing stress in humans, or by exogenously administering doses of stress hormones. In the present thesis both ways were used. Furthermore, when investigating emotional memories, we can make use of memories that are created in a laboratory setting or those that derive from real life experiences, i.e. autobiographical memories. Again, both methods were investigated. We found acute stress and a single cortisol administration to have direct and long-term impairing effects on memory for neutral and emotional information that was learned and reactivated in a controlled laboratory situation. Future studies should shed more light on the generalizability of these findings to real life settings and clinical practice. Show less
Recent studies have suggested that the fetus is capable of exhibiting a stress response to intrauterine needling, resulting in alterations in fetal stress hormone levels. Intrauterine transfusions... Show moreRecent studies have suggested that the fetus is capable of exhibiting a stress response to intrauterine needling, resulting in alterations in fetal stress hormone levels. Intrauterine transfusions are performed by inserting a needle either in the umbilical cord root at the placental surface (PCI), or in the intrahepatic portion of the umbilical vein (IHV). Aim of our study was to test the hypothesis that fetal hormonal changes during intrauterine transfusion are more pronounced when the needle is inserted in the fetal abdomen. Furthermore we aimed to evaluate the effect of fetal analgesia with remifentanil on the fetal stress hormone changes. Exploring the hemodynamic changes following a noxious stimulus, we saw no differences in transfusions through the IHV or the PCI. Remifentanil did not influence the stress hormone changes. We concluded that the stress hormone changes are independent of both site of transfusion and the use of remifentanil. Our results do not confirm nor deny that the fetus is capable to react to a potential painful stimulus, or to show signs of stress or even pain. However, previous research has suggested that presumably painful fetal conditions can lead to alterations in stress reactions after birth. This phenomenon is called ‘fetal programming’. Fetal programming could possibly lead to life-long changes in stress responses and even to increased susceptibility for certain diseases. With the current understanding of fetal pain and fetal analgesia we would advocate the following: 1. Fetal analgesia for invasive procedures should be provided from at least 20 weeks gestation onwards 2. All invasive fetal procedures warrant fetal analgesia, but in procedures involving more than just a single puncture with a thin needle it is obligatory. 3. Analgesics should be given intravenously to the mother. The drug of choice should be ultra-short working (like remifentanil) therefore minimising possible undesirable side-effects to both fetus and mother. Show less
In this thesis, we have studied the potential of the zebrafish larval model in studying the ECS, as a complementary model to the existing rodent models. More specifically, we have looked at the... Show moreIn this thesis, we have studied the potential of the zebrafish larval model in studying the ECS, as a complementary model to the existing rodent models. More specifically, we have looked at the role of the ECS in regulating locomotion and anxiety, and its interaction with the hypothalamic-pituitary-interrenal (HPI) axis, or stress axis. This study has provided us with an interesting animal model which allows for pharmacological screening of Cnr1 agonists, and their involvement in the CNS, as shown by a change in locomotion, anxiety-like behavior and HPI axis activity. The zebrafish larval model can be used as a complementary model to the existing rodent animal models, to study the ECS. The zebrafish larval model brings several interesting features, such as optical transparency and possibilities for high-throughput screening. Furthermore, a complete ECS is present, there is lack of endogenous activity, allowing for exogenous compound screening, and zebrafish data is generally in line with rodent literature. Since the ECS is involved in many diseases, more research of this system may result in the discovery of novel drugs and drug targets. Show less
A general overview of regulation of secondary metabolism in Pseudomonas species is given in Chapter 1. Several approaches were combined to identify novel genes involved in the regulation of PCN... Show moreA general overview of regulation of secondary metabolism in Pseudomonas species is given in Chapter 1. Several approaches were combined to identify novel genes involved in the regulation of PCN synthesis and to study their interactions with other regulators. Site-directed mutagenesis was used to test the hypothesis that rpoS is a regulatory gene of PCN synthesis (Chapter 2). To discover additional genes in the regulatory cascade, which already contains psrA and rpoS, a random DNA-fragment microarray of the PCL1391 genome was constructed and used for transcriptomics of the psrA and rpoS mutants (Chapter 3). A random mutagenesis approach resulted in the identification of pip, a novel gene that stimulates PCN production in PCL1391 (Chapter 4). Analyses on the role of Pip as a switch of PCN production depending on environmental conditions are described in Chapter 5. The results described in this thesis are summarized in Chapter 6, where in addition the regulatory network of PCN synthesis in P. chlororaphis PCL1391 is compared to regulatory networks of secondary metabolism in other Pseudomonas species. Show less
More than 45 years of research on the effects of glucocorticoids on brain function has yielded many insights, but also left a number of longstanding questions. One conundrum has been how activation... Show moreMore than 45 years of research on the effects of glucocorticoids on brain function has yielded many insights, but also left a number of longstanding questions. One conundrum has been how activation of the structurally comparable mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) can lead to very different, or even opposite effects. It also remained unclear how the consequence of activation of a single receptor, GR, can differ from cell to cell and from situation to situation. In this thesis we have investigated two aspects of transcriptional regulation in response to glucocorticoids: the cause of MR/GR specificity, and the role of crosstalk with other transcription factors. Within the hippocampus, we found NeuroD factors to drive the specificity in corticosteroid receptor DNA binding and subsequent gene regulation, i.e. by stimulating MR signaling. We identified Jun dimerization protein 2 (Jdp2) as a stress-responsive MR-specific target gene. In a stress hormone relevant memory task, GR was suggested to act context-dependently and several novel GR target genes were detected. Further elucidation of distinct MR/GR downstream pathways will enable us to better understand the stress physiology and more specifically target aspects of glucocorticoid signaling for treatment of stress-related disorders. Show less
Pronounced ultradian and circadian rhythms in the hormones of the hypothalamic-pituitary-adrenal (HPA) axis (i.e. glucocorticoids), one of the body__s major neuroendocrine axes, were already... Show morePronounced ultradian and circadian rhythms in the hormones of the hypothalamic-pituitary-adrenal (HPA) axis (i.e. glucocorticoids), one of the body__s major neuroendocrine axes, were already demonstrated several decades ago. Until now, the clinical relevance of the pulsatile nature of glucocorticoids was poorly understood or sometimes even regarded as not important. Its evolutionary conservation across many species however implies biological significance. Indeed, glucocorticoids have been proven to be crucial for a plethora of bodily functions, e.g. emotion, cognition and the central mechanism underlying the adaptation to stress. Furthermore, disturbances in the characteristic temporal pattern of glucocorticoid exposure have often been described in stress-related pathology. However, the significance of glucocorticoids secretory patterns for physiology, stress responsiveness and nuclear receptor signalling is still largely unexplored and is accordingly addressed in this thesis. A new concept in the endocrinology of glucocorticoids has evolved from the data presented here showing that pulsatile release of glucocorticoids is a major determinant in __resilience__ of glucocorticoid signalling in neuronal cells and stress responsiveness. Moreover, we show that particularly the glucocorticoid receptor is affected after disrupting glucocorticoid pulsatility and could thus provide an excellent target for therapy to normalise the downstream effects of disturbances in glucocorticoid rhythms in stress-related disease. Show less
During this research we wanted to gain more insight into the potential gene repertoire that is involved in the hippocampus when coping with stress and regulating learning and memory... Show more During this research we wanted to gain more insight into the potential gene repertoire that is involved in the hippocampus when coping with stress and regulating learning and memory processes. To investigate this further we aimed to answer the question:""What are the primary genomic binding sites of the by stress and thus cortisol stimulated protein receptors MR and GR in the hippocampus?" To answer this question, new methods have been applied to determine where exactly MR and GR bind to the DNA, to find out which genes are potentially involved during stress management. As a result we have identified thousands of GR-binding sites at the DNA of which we have analyzed a selection in further detail. One of the identified pathways that have been found to be sensitive for activated GR and corticosteroids is the mTOR pathway. This pathway is involved in neuronal plasticity, which is the fundament for resilience. We have found that expression of the mTOR protein is decreased after exposure to acute stress when the organism has a history of chronic stress. Our results indicate that the reduced resilience after experiencing chronic stress is likely to be mediated by mTOR. Show less
The locus coeruleus, a small brainstem nucleus, is the main source of the chemical norepineprine in the brain and is involved in a number of cognitive functions as well as several neurological and... Show moreThe locus coeruleus, a small brainstem nucleus, is the main source of the chemical norepineprine in the brain and is involved in a number of cognitive functions as well as several neurological and psychiatric disorders. In this dissertation we study the human LC-NE system, the anatomy of this tiny brainstem nucleus and the involvement of the LC-NE system in stress, arousal, cognitive flexibility and physiology (hormones & pupil responses). To date, the LC-NE system has been studied in animals or ex vivo (dead donors). This dissertation is among the first ones to study and visualize the LC-NE system in humans in vivo (alive volunteers) and to approach the human cognition and the study of the LC-NE system in a holistic manner: from central neuromodulators to hormones that are secreted in the body, from anatomy to physiology and cognition. To this end, all chapters were written by taking into consideration theoretical knowledge about the LC-NE system with regard to brain anatomy, cognitive functions, neuromodulation, physiological responses, and clinical applications. Chapters 2 and 3 deal mainly with the anatomy of the LC, while Chapters 4, 5 and 6 concentrate on cognition and human physiology. Additionally Chapters 5 and 6 take also a clinical approach. Show less