Current Protocols in Neuroscience最新文献

Transgenic mouse models of Huntington's disease (HD), a neurodegenerative condition caused by a single gene mutation, have been transformative in their ability to reveal the molecular processes and pathophysiological mechanisms underlying the HD behavioral phenotype. Three model categories have been generated depending on the genetic context in which the mutation is expressed: truncated, full-length, and knock-in. No single model, however, broadly replicates the behavioral symptoms and massive neuronal loss that occur in human patients. The disparity between model and patient requires careful consideration of what each model has to offer when testing potential treatments. Although the translation of animal data to the clinic has been limited, each model can make unique contributions toward an improved understanding of the neurobehavioral underpinnings of HD. Thus, conclusions based on data obtained from more than one model are likely to have the most success in the search for new treatment targets. © 2018 by John Wiley & Sons, Inc.

Resting state functional MRI (fMRI) and functional connectivity are widely applied in humans to examine the role of brain networks in normal function and dysfunction. A similar approach can be taken in rodents, either to obtain translational measures in models of brain disorders or to more carefully examine the neurophysiological underpinnings of the networks. A protocol for resting state functional connectivity in the anesthetized rat, from animal setup to data acquisition to possible pipelines for data analysis, is described. © 2018 by John Wiley & Sons, Inc.

Tissue optical clearing techniques have provided essential tools for visualization of neural networks in unsectioned brain tissue. Here, we describe a passive optical clearing method based on hydrogel embedding, PACT (passive clarity technique), which is relatively simple. Advantages of PACT include tissue transparency, fluorescence preservation, and immunostaining compatibility for obtaining three-dimensional structures of mouse brain tissue. Additionally, it can enhance the penetration of antibodies in immunostaining and allows efficient immunolabeling of large volumes. After clearing with PACT, one can achieve high-resolution imaging in deep tissue at the millimeter-scale level with optical imaging microscopy. © 2018 by John Wiley & Sons, Inc.

The mammalian brain contains tremendous structural and genetic complexity that is vital for its function. The elucidation of gene expression profiles in the brain, coupled with the development of large-scale connectivity maps and emerging viral vector–based approaches for target-selective gene manipulation, now allows for detailed dissection of gene-circuit interfaces. This protocol details how to perform combinatorial viral injections to manipulate gene expression in subsets of neurons interconnecting two brain regions. This method uses stereotaxic injection of a retrograde transducing CAV2-Cre virus into one brain region, combined with injection of a locally transducing Cre-dependent AAV virus into another brain region. This technique is widely applicable to the genetic dissection of neural circuitry, as it enables selective expression of candidate genes, dominant-negatives, fluorescent reporters, or genetic tools within heterogeneous populations of neurons, based upon their projection targets. Curr. Protoc. Neurosci. 65:4.35.1-4.35.20. © 2013 by John Wiley & Sons, Inc.

Super-resolution microscopy has rapidly become an indispensable tool in cell biology and neuroscience by enabling measurement in live cells of structures smaller than the classical limit imposed by diffraction. The most widely applied super-resolution method currently is localization microscopy, which takes advantage of the ability to determine the position of individual fluorescent molecules with nanometer accuracy even in cells. By iteratively measuring sparse subsets of photoactivatable fluorescent proteins, protein distribution in macromolecular structures can be accurately reconstructed. Moreover, the motion trajectories of individual molecules within cells can be measured, providing a unique ability to measure transport kinetics, exchange rates, and binding affinities of even small subsets of molecules with high temporal resolution and great spatial specificity. This unit describes protocols to measure and quantify the distribution of scaffold proteins within single synapses of cultured hippocampal neurons, and to track and measure the diffusion of intracellular constituents of the neuronal plasma membrane. Curr. Protoc. Neurosci. 65:2.20.1-2.20.19. © 2013 by John Wiley & Sons, Inc.

The relationship between inflammation and neuropsychiatric symptoms is of interest to the scientific community for several reasons. A substantial subset of patients suffering from major depressive disorder also exhibit evidence of chronic inflammation including elevated levels of circulating pro-inflammatory cytokines. Immune-mediated inflammatory diseases and immunotherapy can result in depressive symptoms in some patients. Recent evidence suggests that the chronic inflammation may play a role in the pathophysiology of the depressive state, although the specific biological mechanisms are not clear. Herein we describe a model of an inflammation-related depressive phenotype in mice using the tuberculosis vaccine, bacille Calmette-Guérin, to induce chronic inflammation and a subsequent depressive phenotype which is assessed using the tail-suspension test. The model provides an avenue to study not only the molecular and biochemical changes that may be associated with the development of the depressive phenotype, but also pharmacological manipulations of the phenotype. Curr. Protoc. Neurosci. 65:9.46.1-9.46.10. © 2013 by John Wiley & Sons, Inc.

As the power of genetically encoded interventional and observational tools for neuroscience expands, the boundaries of experimental design are increasingly defined by limits in selectively expressing these tools in relevant cell types. Single-recombinase-dependent expression systems have been widely used as a means to restrict gene expression based on single features by combining recombinase-dependent viruses with recombinase-expressing transgenic animals. This protocol details how to create INTRSECT constructs and use multiple recombinases to achieve targeting of a desired gene to subsets of neurons that are defined by multiple genetic and/or topological features. This method includes the design and utilization of both viruses and transgenic animals: these tools are inherently flexible and modular and may be used in different combinations to achieve the desired gene expression pattern. © 2017 by John Wiley & Sons, Inc.

Neurons in the hypothalamus orchestrate homeostatic physiological processes and behaviors essential for life. Defects in the function of hypothalamic neurons cause a spectrum of human diseases, including obesity, infertility, growth defects, sleep disorders, social disorders, and stress disorders. These diseases have been studied in animal models such as mice, but the rarity and relative inaccessibility of mouse hypothalamic neurons and species-specific differences between mice and humans highlight the need for human cellular models of hypothalamic diseases. We and others have developed methods to differentiate human pluripotent stem cells (hPSCs) into hypothalamic neurons and related cell types, such as astrocytes. This protocol builds on published studies by providing detailed step-by-step instructions for neuronal differentiation, quality control, long-term neuronal maintenance, and the functional interrogation of hypothalamic cells by calcium imaging. Together, these protocols should enable any group with appropriate facilities to generate and study human hypothalamic cells. © 2017 by John Wiley & Sons, Inc.

Migraine is a debilitating condition that affects hundreds of millions of people worldwide. A subset of these patients experience chronic migraine, resulting in long-term disability and a severely lowered quality of life. The development of novel migraine therapies has been slow, partially due to the small number of predictive animal models. We have recently developed a novel model of chronic migraine-associated pain, using the known human migraine trigger, nitroglycerin. Injection of nitroglycerin evokes an acute mechanical hyperalgesia, which is sensitive to the acute migraine therapy sumatriptan. In addition, chronic administration of nitroglycerin produces a progressive and sustained decrease in basal mechanical responses, and this hypersensitivity is blocked by migraine preventatives such as topiramate. This mouse model of chronic migraine can be used to study the mechanisms underlying progression of migraine from an episodic to a chronic disorder, and for identifying and screening novel acute and preventive migraine therapies. © 2017 by John Wiley & Sons, Inc.

Neuronal migration is a vital process needed for subsequent assembly and function of neural circuitry during embryonic development. The vast majority of neural progenitors are generated far from their final destination and need to migrate considerable distances to reach their specific cortical layer. Innovations in cell culture techniques and fluorescence microscopy now facilitate the direct visualization of cell movements during cortical development. Here, a detailed protocol to record and analyze a particular type of early migrating neurons, the Cajal Retzius Cells, during the development of the telencephalic vesicles in mammals is described. This method applied to other reporter mouse lines or to electroporated mouse embryos can be also used to analyze the migration of different types of moving neurons during cortical development. © 2017 by John Wiley & Sons, Inc.