In vivo imaging of the diseased nervous system

In vivo microscopy is an exciting tool for neurological research because it can reveal how single cells respond to damage of the nervous system. This helps us to understand how diseases unfold and how therapies work. Here, we review the optical imaging techniques used to visualize the different parts of the nervous system, and how they have provided fresh insights into the aetiology and therapeutics of neurological diseases. We focus our discussion on five areas of neuropathology (trauma, degeneration, ischaemia, inflammation and seizures) in which in vivo microscopy has had the greatest impact. We discuss the challenging issues in the field, and argue that the convergence of new optical and non-optical methods will be necessary to overcome these challenges.     

The development and application of ultrastructural research in mycology

Electron microscopy has contributed a great deal to the field of mycology. Fungal ultrastructure has been, and continues to be, a key research element in the study of spore development and germination, host-pathogen interactions, nuclear behavior, and studies of subcellular organelles and organization linking structure and function. Since the earliest research in transmission electron microscopy in the 1950s, mycologists have kept pace with the developments in all areas of electron microscopy and have used them to great advantage in generating fine structural information on fungi. These recent developments include the use of scanning electron microscopy in the 1960s, X-ray microanalysis, cryopreservation and immunoelectron microscopy in the 1970s and 1980s. All of these techniques will continue to provide mycologists with the means to gain morphological and analytical data at the ultrastructural level.Presented as part of the Everett S. Beneke Symposium in Mycology, May 27, 1988.     

Applying microscopy to the analysis of nuclear structure and function

One of the ultimate goals of biological research is to understand mechanisms of cell function within living organisms. With this in mind, many sophisticated technologies that allow us to inspect macromolecular structure in exquisite detail have been developed. Although knowledge of structure derived from techniques such as X-ray crystallography and nuclear magnetic resonance is of vital importance, these approaches cannot reveal the remarkable complexity of molecular interactions that exists in vivo. With this in mind, this review focuses on the use of microscopy techniques to analyze cell structure and function. We describe the different basic microscopic methodologies and how the routine techniques are best applied to particular biological problems. We also emphasize the specific capabilities and uses of light and electron microscopy and highlight their individual advantages and disadvantages. For completion, we also comment on the alternative possibilities provided by a variety of advanced imaging technologies. We hope that this brief analysis of the undoubted power of microscopy techniques will be enough to stimulate a wider participation in this rapidly developing area of biological discovery.     

可持续发展目标关系研究进展

《2030可持续发展议程》指出17项可持续发展目标之间存在着相互联系,并且是整体而不可分割的,但并未说明各项目标之间是如何相关联的,因此限制了可持续发展目标的落实。理清各项可持续发展目标之间的关系,是加快可持续发展目标落实、促进政策一致性实现的保障。由于我国目前关于此方面的报道非常有限,因此有必要对17项可持续发展目标之间关系的研究进展进行总结。为了较全面的了解研究背景,首先简要回顾了千年发展目标到可持续发展目标的转变过程;随后在综合分析已有文献内容的基础上,分别从"联结途径""相互作用程度""网络分析""可持续发展目标模型"以及"执行手段"等五个方面对已有研究进行了论述,并总结当前研究的不足与未来挑战;最后分析了当前研究对我国未来可持续发展目标落实的启示,主要包括:(1)明确我国各项可持续发展目标的关系,促进不同层级政府和管理部门间政策一致性的实现;(2)完善指标监测体系,消除数据缺口;(3)加快构建我国可持续发展目标模型。     

Seeing is believing: the impact of electron microscopy on autophagy research

Autophagy was first discovered by transmission electron microscopy more than 50 years ago. For decades, electron microscopy was the only way to reliably detect autophagic compartments in cells because no specific protein markers were known. In the 1970s, however, the introduction of biochemical methods enabled quantitative studies of autophagic-lysosomal degradation, and in the 1980s specific biochemical assays for autophagic sequestration became available. Since the identification of autophagy-related genes in the 1990s, combined fluorescence microscopy, biochemical and genetic methods have taken the leading role in autophagy research. However, electron microscopy is still needed to confirm and verify results obtained by other methods, and also to produce novel knowledge that would not be achievable by any other experimental approach. Confocal microscopy, with its ever-improving resolution, is probably the best-suited morphological approach to investigate the dynamic aspects of autophagy. However, for analyzing the ultrastructural details of the many novel organelles and mechanisms involved in specific subtypes of autophagy, the electron microscope is still indispensable. This review will summarize the impact that electron microscopy has had on autophagy research since the discovery of this self-degradation process in the mid-1950s. Astonishingly, some of the "novel" concepts and principles of autophagy, presented in the recent studies, were already proposed several decades ago by the pioneering, accurate and passionate work of virtuoso electron microscopists.     

Advances in visualization of copper in mammalian systems using X-ray fluorescence microscopy

Synchrotron-based X-ray fluorescence microscopy (XFM) has become an important imaging technique to investigate elemental concentrations and distributions in biological specimens. Advances in technology now permit imaging at resolutions rivaling that of electron microscopy, and researchers can now visualize elemental concentrations in subcellular organelles when using appropriate correlative methods. XFM is an especially valuable tool to determine the distribution of endogenous trace metals that are involved in neurodegenerative diseases. Here, we discuss the latest research on the unusual copper (Cu) storage vesicles that were originally identified in mouse brains and the involvement of Cu in Alzheimer's disease. Finally, we provide an outlook of how future improvements to XFM will drive current trace element research forward.     

3D and 4D imaging of immune cells in vitro and in vivo

Analyzing the dynamics of cellular immune responses, although performed for decades in immunologic research, has seen an enormous increase in the number of studies using this approach since the development of intravital 2-photon microscopy. Meanwhile, new insights into the dynamics of cellular immunity are being published on a daily basis. This review gives a short overview of the currently most widely used techniques, both on the microscopy side as well as on the experimental part. Difficulties and promises will be discussed. Finally, a personal selection of the most interesting findings of the first 6 years of intravital 2-photon microscopy for immunological questions will be given. The overall aim is to get the reader interested into this fascinating way of investigating the immune response by means of “dynamic histology”. This already has and will continue to broaden our view on how immune cells work in real life.     

The combined role of the main olfactory and vomeronasal systems in social communication in mammals

The main olfactory and the vomeronasal systems are the two systems by which most vertebrates detect chemosensory cues that mediate social behavior. Much research has focused on how one system or the other is critical for particular behaviors. This has lead to a vision of two distinct and complexly autonomous olfactory systems. A closer look at research over the past 30 years reveals a different picture however. These two seemingly distinct systems are much more integrated than previously thought. One novel set of chemosensory cues in particular (MHC Class I peptide ligands) can show us how both systems are capable of detecting the same chemosensory cues, through different mechanisms yet provide the same general information (genetic individuality). Future research will need to now focus on how two seemingly distinct chemosensory systems together detect pheromones and mediate social behaviors. Do these systems work independently, synergistically or competitively in communicating between individuals of the same species?     

Identification of Metal Oxide Nanoparticles in Histological Samples by Enhanced Darkfield Microscopy and Hyperspectral Mapping

Nanomaterials are increasingly prevalent throughout industry, manufacturing, and biomedical research. The need for tools and techniques that aid in the identification, localization, and characterization of nanoscale materials in biological samples is on the rise. Currently available methods, such as electron microscopy, tend to be resource-intensive, making their use prohibitive for much of the research community. Enhanced darkfield microscopy complemented with a hyperspectral imaging system may provide a solution to this bottleneck by enabling rapid and less expensive characterization of nanoparticles in histological samples. This method allows for high-contrast nanoscale imaging as well as nanomaterial identification. For this technique, histological tissue samples are prepared as they would be for light-based microscopy. First, positive control samples are analyzed to generate the reference spectra that will enable the detection of a material of interest in the sample. Negative controls without the material of interest are also analyzed in order to improve specificity (reduce false positives). Samples can then be imaged and analyzed using methods and software for hyperspectral microscopy or matched against these reference spectra in order to provide maps of the location of materials of interest in a sample. The technique is particularly well-suited for materials with highly unique reflectance spectra, such as noble metals, but is also applicable to other materials, such as semi-metallic oxides. This technique provides information that is difficult to acquire from histological samples without the use of electron microscopy techniques, which may provide higher sensitivity and resolution, but are vastly more resource-intensive and time-consuming than light microscopy.     

Post‐GWAS in Psychiatric Genetics: A Developmental Perspective on the “Other” Next Steps

As psychiatric genetics enters an era where gene identification is finally yielding robust, replicable genetic associations and polygenic risk scores, it is important to consider next steps and delineate how that knowledge will be applied to ultimately ameliorate suffering associated with substance use and psychiatric disorders. Much of the post‐genome‐wide association study discussion has focused on the potential of genetic information to elucidate the underlying biology and use this information for the development of more effective pharmaceutical treatments. In this review we focus on additional areas of research that should follow gene identification. By taking genetic findings into longitudinal, developmental studies, we can map the pathways by which genetic risk manifests across development, elucidating the early behavioral manifestations of risk, and studying how various environments and interventions moderate that risk across developmental stages. The delineation of risk across development will advance our understanding of mechanism, sex differences and risk and resilience processes in different racial/ethnic groups. Here, we review how the extant twin study literature can be used to guide these efforts. Together, these new lines of research will enable us to develop more informed, tailored prevention and intervention efforts.     

Presynaptic neurotoxins: An expanding array of natural and modified molecules

The process of neurotransmitter release from nerve terminals is a target for a wide array of presynaptic toxins produced by various species, from humble bacteria to arthropods to vertebrate animals. Unlike other toxins, most presynaptic neurotoxins do not kill cells but simply inhibit or activate synaptic transmission. In this review, we describe two types of presynaptic neurotoxins: clostridial toxins and latrotoxins, which are, respectively, the most potent blockers and stimulators of neurotransmitter release. These toxins have been instrumental in defining presynaptic functions and are now widely used in research and medicine. Here, we would like to analyse the diversity of these toxins and demonstrate how the knowledge of their structures and mechanisms of action can help us to design better tools for research and medical applications. We will look at natural and synthetic variations of these exquisite molecular machines, highlighting recent advances in our understanding of presynaptic toxins and questions that remain to be answered. If we can decipher how a given biomolecule is modified by nature to target different species, we will be able to design new variants that carry only desired characteristics to achieve specific therapeutic, agricultural or research goals. Indeed, a number of research groups have already initiated a quest to harness the power of natural toxins with the aim of making them more specifically targeted and safer for future research and medical applications.     

Towards an ethical and legal framework in archeogenomics: A local case in the Atlantic coast of central Patagonia

Ethical discussions around ancient DNA (aDNA) research predate the technological breakthroughs that led to the accelerated generation of ancient genomic data, revealing a long-due need to address these aspects in the field. Given the diverse conflicts that genomics has raised towards the communities associated with the Non-living Human Ancestors under study, it has been suggested that the ethical and legal implications of genetically studying present-day and ancient human populations should be considered case-by-case. Nevertheless, the discussions have focused on US and European perspectives. To contribute from a local and Latin American position to the problem, we present the history of consensus and disagreement of the relationships between scientists and Indigenous communities of the Atlantic coast of the central Argentinian Patagonia. We describe how these relationships resulted in the approval of a groundbreaking provincial law that acknowledges the Indigenous community's right to be involved in decision-making concerning their Ancestors. In addition, we emphasize how these established relationships allowed the development of aDNA studies. With this background, we address the main ethical concerns of genomic studies of Ancestors identified in the reference literature and commit to applying some of the recommendations suggested in those ethical guidelines. Then, we reflect on possible negative consequences of ongoing research and propose some suggestions based on personal experiences that will contribute to moving the ethical field towards a more contextualized science with a local perspective.     

Ecosystem disservices research: A review of the state of the art with a focus on cities

Ecosystem services, the benefits produced by ecosystem functions and structures for human well-being, have received continuous international attention since the publication of the Millennium Ecosystem Assessment (MA) and the TEEB study (The Economics of Ecosystem Services and Biodiversity). Ecosystem functions also have effects that are harmful to human well-being, and these effects are called ecosystem disservices (EDS). The aim of this paper is to explore how ecosystem disservices have been recognised in the scientific literature and how the concept has been used in the discussion of socio-ecological systems. The paper analyses 103 studies on EDS. We use a quantitative approach to assess geographical spread, focus and indicator choice. This quantitative picture is supplemented by a qualitative discussion of the effects of ecosystem disservices on urban systems and cities. The results of the review show that although the idea of detrimental ecosystem effects is not new, systematic research on EDS has only just begun. Most studies on EDS focus on Western Europe or the USA. EDS have been more frequently discussed in the most human-dominated ecosystem types: i.e., in agricultural and urban ecosystems. The latter in particular will be central for future research on EDS, considering that more than 75% of the world's population is expected to live in urban environments by 2050.     

The combined role of the main olfactory and vomeronasal systems in social communication in mammals

The main olfactory and the vomeronasal systems are the two systems by which most vertebrates detect chemosensory cues that mediate social behavior. Much research has focused on how one system or the other is critical for particular behaviors. This has lead to a vision of two distinct and complexly autonomous olfactory systems. A closer look at research over the past 30 years reveals a different picture however. These two seemingly distinct systems are much more integrated than previously thought. One novel set of chemosensory cues in particular (MHC Class I peptide ligands) can show us how both systems are capable of detecting the same chemosensory cues, through different mechanisms yet provide the same general information (genetic individuality). Future research will need to now focus on how two seemingly distinct chemosensory systems together detect pheromones and mediate social behaviors. Do these systems work independently, synergistically or competitively in communicating between individuals of the same species?     

Nanoscale organization of the pre-synapse: Tracking the neurotransmitter release machinery

Chemical communication is underpinned by the fusion of neurotransmitter-containing synaptic vesicles with the plasma membrane at active zones. With the advent of super-resolution microscopy, the door is now opened to unravel the dynamic remodeling of synapses underpinning learning and memory. Imaging proteins with conventional light microscopy cannot provide submicron information vital to determining the nanoscale organization of the synapse. We will first review the current super-resolution microscopy techniques available to investigate the localization and movement of synaptic proteins and how they have been applied to visualize the synapse. We discuss the new techniques and analytical approaches have provided comprehensive insights into synaptic organization in various model systems. Finally, this review provides a brief update on how these super-resolution techniques and analyses have opened the way to a much greater understanding of the synapse, the fusion and compensatory endocytosis machinery.     

Understanding the performance and impact of public knowledge translation funding interventions: Protocol for an evaluation of Canadian institutes of health research knowledge translation funding programs

ABSTRACT: BACKGROUND: The Canadian Institutes of Health Research (CIHR) has defined knowledge translation (KT) as a dynamic and iterative process that includes the synthesis, dissemination, exchange, and ethically-sound application of knowledge to improve the health of Canadians, provide more effective health services and products, and strengthen the healthcare system. CIHR, the national health research funding agency in Canada, has undertaken to advance this concept through direct research funding opportunities in KT. Because CIHR is recognized within Canada and internationally for leading and funding the advancement of KT science and practice, it is essential and timely to evaluate this intervention, and specifically, these funding opportunities. DESIGN: The study will employ a novel method of participatory, utilization-focused evaluation inspired by the principles of integrated KT. It will use a mixed methods approach, drawing on both quantitative and qualitative data, and will elicit participation from CIHR funded researchers, knowledge users, KT experts, as well as other health research funding agencies. Lines of inquiry will include an international environmental scan, document/data reviews, in-depth interviews, targeted surveys, case studies, and an expert review panel. The study will investigate how efficiently and effectively the CIHR model of KT funding programs operates, what immediate outcomes these funding mechanisms have produced, and what impact these programs have had on the broader state of health research, health research uptake, and health improvement. DISCUSSION: The protocol and results of this evaluation will be of interest to those engaged in the theory, practice, and evaluation of KT. The dissemination of the study protocol and results to both practitioners and theorists will help to fill a gap in knowledge in three areas: the role of a public research funding agency in facilitating KT, the outcomes and impacts KT funding interventions, and how KT can best be evaluated.     

Beyond electrostatics: Antimicrobial peptide selectivity and the influence of cholesterol-mediated fluidity and lipid chain length on protegrin-1 activity

Antimicrobial peptides (AMPs) are a promising class of innate host defense molecules for next-generation antibiotics, as they uniquely target and permeabilize membranes of pathogens. This selectivity has been explained by the electrostatic attraction between these predominantly cationic peptides and the bacterial membrane, which is heavily populated with anionic lipids. However, AMP-resistant bacteria have non-electrostatic countermeasures that modulate membrane rigidity and thickness. We explore how variations in physical properties affect the membrane affinity and disruption process of protegrin-1 (PG-1) in phosphatidylcholine (PC) membranes with altered lipid packing densities and thicknesses. From isothermal titration calorimetry and atomic force microscopy, our results showed that PG-1 could no longer insert into membranes of increasing cholesterol amounts nor into monounsaturated PC membranes of increasing thicknesses with similar fluidities. Prevention of PG-1’s incorporation consequently made the membranes more resistant to peptide-induced structural transformations like pore formation. Our study provides evidence that AMP affinity and activity are strongly correlated with the fluidity and thickness of the membrane. A basic understanding of how physical mechanisms can regulate cell selectivity and resistance towards AMPs will aid in the development of new antimicrobial agents.     

Biodiversity and ecosystem function: the consumer connection

Proposed links between biodiversity and ecosystem processes have generated intense interest and controversy in recent years. With few exceptions, however, empirical studies have focused on grassland plants and laboratory aquatic microbial systems, whereas there has been little attention to how changing animal diversity may influence ecosystem processes. Meanwhile, a separate research tradition has demonstrated strong top‐down forcing in many systems, but has considered the role of diversity in these processes only tangentially. Integration of these research directions is necessary for more complete understanding in both areas. Several considerations suggest that changing diversity in multi‐level food webs can have important ecosystem effects that can be qualitatively different than those mediated by plants. First, extinctions tend to be biased by trophic level: higher‐level consumers are less diverse, less abundant, and under stronger anthropogenic pressure on average than wild plants, and thus face greater risk of extinction. Second, unlike plants, consumers often have impacts on ecosystems disproportionate to their abundance. Thus, an early consequence of declining diversity will often be skewed trophic structure, potentially reducing top‐down influence. Third, where predators remain abundant, declining diversity at lower trophic levels may change effectiveness of predation and penetrance of trophic cascades by reducing trait diversity and the potential for compensation among species within a level. The mostly indirect evidence available provides some support for this prediction. Yet effects of changing animal diversity on functional processes have rarely been tested experimentally. Evaluating impacts of biodiversity loss on ecosystem function requires expanding the scope of current experimental research to multi‐level food webs. A central challenge to doing so, and to evaluating the importance of trophic cascades specifically, is understanding the distribution of interaction strengths within natural communities and how they change with community composition. Although topology of most real food webs is extremely complex, it is not at all clear how much of this complexity translates to strong dynamic linkages that influence aggregate biomass and community composition. Finally, there is a need for more detailed data on patterns of species loss from real ecosystems (community “disassembly” rules).     

Animal models for Alzheimer's disease and frontotemporal dementia: a perspective

In dementia research, animal models have become indispensable tools. They not only model aspects of the human condition, but also simulate processes that occur in humans and hence provide insight into how disease is initiated and propagated. The present review discusses two prominent human neurodegenerative disorders, Alzheimer''s disease and frontotemporal dementia. It discusses what we would like to model in animals and highlights some of the more recent achievements using species as diverse as mice, fish, flies and worms. Advances in imaging and therapy are explored. We also discuss some anticipated new models and developments. These will reveal how key players in the pathogenesis of Alzheimer''s disease and frontotemporal dementia, such as the peptide Aβ (amyloid β) and the protein tau, cause neuronal dysfunction and eventually, neuronal demise. Understanding these processes fully will lead to early diagnosis and therapy.