Lateral Diffusion and Exocytosis of Membrane Proteins in Cultured Neurons Assessed using Fluorescence Recovery and Fluorescence-loss Photobleaching
This report describes the use of live cell imaging and photobleach techniques to determine the surface expression, transport pathways and trafficking kinetics of exogenously expressed, pH-sensitive GFP-tagged proteins at the plasma membrane of neurons.
Morphological Analysis of Drosophila Larval Peripheral Sensory Neuron Dendrites and Axons Using Genetic Mosaics
The dendritic arborization sensory neurons of the Drosophila larval peripheral nervous system are useful models to elucidate both general and neuron class-specific mechanisms of neuron differentiation. We present a practical guide to generate and analyze dendritic arborization neuron genetic mosaics.
Visualization and Genetic Manipulation of Dendrites and Spines in the Mouse Cerebral Cortex and Hippocampus using In utero Electroporation
1Division of Molecular Neurobiology, MRC National Institute for Medical Research, 2Confocal and Image Analysis Laboratory, National Institute for Medical Research, 3Physiopathologie de la plasticité neuronale, Neurocentre Magendie, Université de Bordeaux
This article describes in detail a protocol to electroporate in utero the cerebral cortex and the hippocampus at E14.5 in mice. We also show that this is a valuable method to study dendrites and spines in these two cerebral regions.
We present a protocol that permits to view and to quantitatively asses the morphology of the dendritic tree of individual Purkinje cells grown in organotypic cerebellar slice cultures. This protocol is intended to promote studies on the mechanisms of Purkinje cell dendritic development.
We describe a protocol for using bone morphogenetic protein-7 (BMP-7) or Matrigel to selectively induce dendritic growth in primary sympathetic neurons dissociated from the superior cervical ganglia (SCG) of perinatal rats.
Immunohistological Labeling of Microtubules in Sensory Neuron Dendrites, Tracheae, and Muscles in the Drosophila Larva Body Wall
To understand how complex cell shapes, such as neuronal dendrites, are achieved during development, it is important to be able to accurately assay microtubule organization. Here we describe a robust immunohistological labeling method to examine microtubule organization of dendritic arborization neuron sensory dendrites, trachea, muscle, and other Drosophila larva body wall tissues.
We have developed a computer program to analyze neuronal morphology. In combination with two existing open source analysis tools, our program performs Sholl analysis and determines the number of neurites, branch points, and neurite tips. The analyses are performed so that local changes in neurite morphology can be observed.
1Section on Neuronal Structure, Laboratory for Integrative Neuroscience, NIAAA, NIH, 2Department Physiology and Pharmacology, Wake Forest University Health Sciences, 3Oregon National Primate Research Center, Division of Neuroscience, Oregon Health and Science University
We demonstrate the use of the gene gun to introduce fluorescent dyes, such as DiI, into neurons in brain slices from rodents and non-human primates of different ages. In this particular case, we use adult mice (3-6 months old) and adult cynomologus monkeys (9-15 years old). This technique, originally described by the laboratory of Dr. Lichtman (Gan et al., 2000), is well suited for the study of dendritic branching and dendritic spine morphology and can be combined with traditional immunostaining, if detergents are kept at a low concentration.
In this video and supplemental material, we show a protocol for chronic in vivo imaging of the intact brain using a thinned-skull preparation.
This article describes a method by which one can mimic in vivo development of the Drosophila mushroom body in an ex vivo culture system.
In this video-article we present a method for the isolation and purification of Drosophila peripheral neurons using a fast magnetic bead assisted cell sorting strategy. RNA obtained from the isolated cells can be readily used for downstream applications including microarray analyses.
Numerous recent studies have identified mutations in synaptic proteins associated with brain pathologies. Primary cultured cortical neurons offer great flexibility in examining the effects of these disease-associated proteins on dendritic spine morphology and motility.
Fluorescence Recovery After Photobleaching (FRAP) of Fluorescence Tagged Proteins in Dendritic Spines of Cultured Hippocampal Neurons
FRAP has been used to quantify the mobility of Green Fluorescence Protein (GFP)-tagged proteins in cultured cells. We examined the mobile/immobile fractions of the GFP by analyzing the fluorescence recovery percentage after photobleaching. In this study, FRAP was performed at spines of hippocampal neurons.
Voltage-sensitive Dye Recording from Axons, Dendrites and Dendritic Spines of Individual Neurons in Brain Slices
An imaging technique for monitoring of membrane potential changes with sub-micrometer spatial and sub-millisecond temporal resolution is described. The technique, based on laser excitation of voltage-sensitive dyes, allows measurements of signals in axons and axon collaterals, terminal dendritic branches, and individual dendritic spines.
Patterned Photostimulation with Digital Micromirror Devices to Investigate Dendritic Integration Across Branch Points
Digital micromirror devices (DMD) can generate complex patterns in time and space with which to control neuronal excitability. Issues relevant to the design, construction, and operation of DMD systems are discussed. Such a system enabled the demonstration of non-linear integration across distal dendritic branch points.
In situ patch clamp recordings are used for electrophysiological characterization of neurons in intact circuitry. In the Drosophila genetic model patch clamping is difficult because the CNS is small and surrounded by a robust sheath. This article describes the procedure to remove the sheath and clean neurons for subsequent patch clamp recordings.
Imaging Analysis of Neuron to Glia Interaction in Microfluidic Culture Platform (MCP)-based Neuronal Axon and Glia Co-culture System
This study describes the procedures of setting up a novel neuronal axon and (astro)glia co-culture platform. In this co-culture system, manipulation of direct interaction between a single axon (and single glial cell) becomes feasible, allowing mechanistic analysis of the mutual neuron to glial signaling.
1Department of Biochemistry and Molecular Biology, The University of Texas MD Anderson Cancer Center, 2Scholars Academy/MARC Scholar, University of Houston-Downtown, 3Genes and Development Graduate Program, University of Texas Graduate School of Biomedical Sciences, 4Neuroscience Graduate Program, University of Texas Graduate School of Biomedical Sciences
In this article, we demonstrate assays to study thermal nociception in Drosophila larvae. One assay involves spatially-restricted (local) stimulation of thermal nociceptors1,2 while the second involves a wholesale (global) activation of most or all such neurons3. Together, these techniques allow visualization and quantification of the behavioral functions of Drosophila nociceptive sensory neurons.
In this video-article we present a method for isolating single or multiple Drosophila da neurons from third instar larvae using the infrared capture (IR) class of Laser Capture Microdissection (LCM). RNA obtained from the isolated neurons can be readily used for downstream applications including qRT-PCR or microarray analyses.
1Department of Otolaryngology-Head and Neck Surgery, Virginia Merrill Bloedel Hearing Research Center, University of Washington, 2Department of Physiology and Biophysics, Virginia Merrill Bloedel Hearing Research Center, University of Washington
The chicken auditory brainstem is comprised of nuclei responsible for binaural sound processing. A single coronal slice preparation maintains the entire circuitry while the cultured approach provides a unique preparation to study the development of neuronal structure and auditory function at the molecular, cellular and network levels.
This protocol outlines the steps required to dissect, transfect via electroporation and culture mouse hippocampal and cortical neurons. Short-term cultures may be used for studies of axon outgrowth and guidance, while long-term cultures can be used for studies of synaptogenesis and dendritic spine analysis.
Postsynaptic Recordings at Afferent Dendrites Contacting Cochlear Inner Hair Cells: Monitoring Multivesicular Release at a Ribbon Synapse
1Department of Otolaryngology-Head and Neck Surgery., The Johns Hopkins School of Medicine, 2Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas
Whole-cell patch-clamp recordings from auditory nerve fiber dendrites at the inner hair cell ribbon synapse in the mammalian cochlea.
We describe a protocol for transcardiac perfusion of mice, removal and sectioning of the brain, as well as immunoperoxidase staining, resin embedding, and ultrathin sectioning of the brain sections. Upon completion of these procedures, the immunostained material is ready for examination with transmission electron microscopy.
In mice, the ability to detect pheromones is principally mediated by the vomeronasal organ (VNO). Here, an acute tissue slice preparation of VNO for performing calcium imaging is described. This physiological approach allows observations of subpopulations and/or individual neurons in a living tissue and is convenient for receptor-ligand identification.
Preparation of Parasagittal Slices for the Investigation of Dorsal-ventral Organization of the Rodent Medial Entorhinal Cortex
We describe procedures for preparation and electrophysiological recording from brain slices that maintain the dorsal-ventral axis of the medial entorhinal cortex (MEC). Because neural encoding of location follows a dorsal-ventral organization within the MEC, these procedures facilitate investigation of cellular mechanisms important for navigation and memory.
Here we describe a protocol for the preparation of agar-embedded retinal slices that are suitable for electrophysiology and Ca2+ imaging. This method allows one to study ribbon-type synapses in retinal microcircuits using direct patch-clamp recordings of single presynaptic nerve terminals.
Odorant-induced Responses Recorded from Olfactory Receptor Neurons using the Suction Pipette Technique
Olfactory receptor neurons (ORNs) convert odor signals first into a receptor current that in turn triggers action potentials that are conveyed to second order neurons in the olfactory bulb. Here we describe the suction pipette technique to record simultaneously the odorant-induced receptor current and action potentials from mouse ORNs.
Methods for Study of Neuronal Morphogenesis: Ex vivo RNAi Electroporation in Embryonic Murine Cerebral Cortex
1Department of Molecular, Cellular Biology and Biochemistry, Brown University, 2Institute for Brain Science, Brown University, 3Department of Psychiatry and Human Behavior, Warren Alpert School of Medicine, Brown University
To conduct a rapid assessment of the function of genes in the development of cerebral cortex, we describe methods involving the ex vivo electroporation of plasmids co-expressing inhibitory RNA (RNAi) and GFP in murine embryonic cortex. This protocol is amenable to the study of various aspects of neurodevelopment such as neurogenesis, neuronal migration and neuronal morphogenesis including dendrite and axon outgrowth.
An alternative way of isolating mouse embryonic motoneurons from the spinal cord is described. The method takes into account the fact that lectin can bind to the low affinity nerve growth factor receptor p75NTR. This lectin-based preplating allows a purification similar to that with a specific antibody against the p75NTR.
We provide a practical guide for delivering tracers in vivo and use the spinocerebellar pathway as a model system to demonstrate essential steps for successful neuronal circuit analysis in mice. We describe in detail our versatile tracing protocol that exploits wheat germ agglutinin (WGA) conjugated to Alexa fluorophores.
A method to immunostain and visualize chordotonal organs in larvae and pupae of Drosophila melanogaster is described.
The Three-Dimensional Human Skin Reconstruct Model: a Tool to Study Normal Skin and Melanoma Progression
In this report, we describe the three-dimensional skin reconstruct model which mimics human skin in architecture and composition. Melanocyte physiology, melanoma progression and the fate of dermal stem cells have been investigated using the skin reconstruct model. The model is also useful as a preclinical tool for drug assessment.
1Department of Physics, University of California, San Diego, 2Department of Engineering Science and Mechanics, Pennsylvania State University, 3Department of Neurosurgery, Pennsylvania State University, 4Section of Neurobiology, University of California, San Diego
We present a method to form an imaging window in the mouse skull that spans millimeters and is stable for months without inflammation of the brain. This method is well suited for longitudinal studies of blood flow, cellular dynamics, and cell/vascular structure using two-photon microscopy.
The Giant Fiber System is a simple neuronal circuit of adult Drosophila melanogaster containing the largest neurons in the fly. We describe the protocol for monitoring synaptic transmission through this pathway by recording post synaptic potentials in dorsal longitudinal (DLM) and tergotrochanteral (TTM) muscles following direct stimulation of the Giant Fiber interneurons.
This video and protocol demonstrate how to implant a glass-covered cranial window in rodents. These preparations can be used for chronic in vivo two-photon imaging of the neocortex over time scales of months. It may also be used for other types of imaging, including optical intrinsic signal imaging.
This is a protocol to prepare and maintain a neocortical slice preparation in organotypic culture for the purpose of making electrical recordings from pyramidal neurons.
Astrocytes have been recognized to be versatile cells participating in fundamental biological processes that are essential for normal brain development and function, and central nervous system repair. Here we present a rapid procedure to obtain pure mouse astrocyte cultures to study the biology of this major class of central nervous system cells.
Membrane Potentials, Synaptic Responses, Neuronal Circuitry, Neuromodulation and Muscle Histology Using the Crayfish: Student Laboratory Exercises
The experiments demonstrate an easy approach for students to gain experience in examining muscle structure, synaptic responses, the effects of ion gradients and permeability on membrane potentials. Also, a sensory-CNS-motor-muscle circuit is presented to show a means to test effects of compounds on a neuronal circuit.
Targeted Labeling of Neurons in a Specific Functional Micro-domain of the Neocortex by Combining Intrinsic Signal and Two-photon Imaging
A method is described for labeling neurons with fluorescent dyes in predetermined functional micro-domains of the neocortex. First, intrinsic signal optical imaging is used to obtain a functional map. Then two-photon microscopy is used to label and image neurons within a micro-domain of the map.
A novel impulsive cell pressurization experiment has been developed using a Kolsky bar device to investigate the molecular/cellular mechanisms of blast-induced traumatic brain injury.
By tagging the extracellular domains of membrane receptors with superecliptic pHluorin, and by imaging these fusion receptors in cultured mouse neurons, we can directly visualize individual vesicular insertion events of the receptors to the plasma membrane. This technique will be instrumental in elucidating the molecular mechanisms governing receptor insertion to the plasma membrane.
Right-angle microprisms inserted into the mouse neocortex allows for deep imaging of multiple cortical layers with a viewpoint typically found in slice. One-millimeter microprisms offer a wide field-of-view (~900 μm) and spatial resolutions sufficient to resolve dendritic spines. We demonstrate layer V neuronal imaging and neocortical vascular imaging using microprisms.
Traditionally the vertical slice and the whole-mount preparation of the retina have been used to study the function of retinal circuits. Here, we describe the novel slicing method to preserve the dendritic morphology of retinal neurons intact.
Selective Viral Transduction of Adult-born Olfactory Neurons for Chronic in vivo Optogenetic Stimulation
Adult-born neurons of the olfactory bulb can be optogenetically controlled using Channelrhodopsin2-expressing lentiviral injection in the rostral migratory stream and chronic photostimulation with an implanted miniature LED.
1Division of Neurology, Children's Hospital of Philadelphia, 2Neuroscience Graduate Group, Perelman School of Medicine at the University of Pennsylvania, 3Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania
A multi-faceted approach to investigating functional changes to hippocampal circuitry is explained. Electrophysiological techniques are described along with the injury protocol, behavioral testing and regional dissection method. The combination of these techniques can be applied in similar fashion for other brain regions and scientific questions.
1Department of Biomedical Engineering, University of California, Irvine (UCI), 2Stem Cell Research Center, University of California, Irvine (UCI), 3Institute for Brain Aging and Dementia, University of California, Irvine (UCI)
In this video we demonstrate the technique of soft lithography with polydimethyl siloxane (PDMS) which we use to farbricate a microfluidic device for culturing neurons.
This video demonstrates the procedure for differentiating myeloid dendritic cells from mouse bone marrow. Isolation of mouse tibia and femur, and processing of bone marrow are demonstrated. Pictures demonstrating cell morphology before and after differentiation, and figures depicting cell phenotype and IL-12 production following maturation using CpG are shown.
We developed a novel multi-compartment neuron co-culture microsystem platform for in vitro CNS axon-glia interaction research. The platform is capable of conducting up to six independent experiments in parallel and was fabricated using a newly developed macro/micro hybrid fabrication method.
An Isolated Retinal Preparation to Record Light Response from Genetically Labeled Retinal Ganglion Cells
This article provides a description of how to dissect and record from the isolated retinal preparation in mouse. In particular, we describe how to record light responses from a fluorescently labeled ganglion cell population and subsequently identify and analyze its morphology.
Ex utero Electroporation and Whole Hemisphere Explants: A Simple Experimental Method for Studies of Early Cortical Development
This protocol describes an improved explant procedure that involves ex utero electroporation, dissection and culture of entire cerebral hemispheres from the embryonic mouse. The preparation facilitates pharmacological studies and assays of gene function during early cortical development.