NIH NIBIB RO1: 1R01EB009103-01 Clinical Neuroengineering Training Program (1 T90 DK070079-01) Wallace H Coulter Foundation NIH Institutional Clinical and Translational Science Award NIH/NCRR 1KL2RR025012-01 Wisconsin Alumni Research Foundation

Experimental Procedure
<ol>
<li>Connecting the EEG Electrodes<ol>
<li>Electrodes will be attached to the scalp using an EEG cap; this simplifies the process of ensuring that the electrodes are in the proper location on the scalp, as specified by the 10-20 international system.</li>
<li>To place the cap, mark the vertex on the subject's scalp using a felt-tip pen or some other similar method. To do so, begin by locating the nasion and inion on the subject. Using a tape measure, find the distance between these two locati...

<ol>
	<li>Fabiani, G. E., McFarland, D. J., Wolpaw, J. R., Pfurtscheller, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conversion+of+eeg+activity+into+cursor+movement+by+a+brain-computer+interface+(bci).">Conversion of eeg activity into cursor movement by a brain-computer interface (bci).</a> IEEE transactions on neural systems and rehabilitation engineering. 12 (3), 331-338 (2004).</li><li>Wolpaw, J. R., McFarland, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+a+two-dimensional+movement+signal+by+a+noninvasive+brain-computer+interface+in+humans.">Control of a two-dimensional movement signal by a noninvasive brain-computer interface in humans.</a> Proc Natl Acad Sci USA. 101 (51), 17849-17854 (2004).</li><li>Schalk, G., McFarland, D. J., Hinterberger, T., Birbaumer, N., Wolpaw, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bci2000:+a+general-purpose+brain-computer+interface+(BCI)+system.">Bci2000: a general-purpose brain-computer interface (BCI) system.</a> IEEE transactions on bio-medical engineering. 51 (6), 1034-1043 (2004).</li></ol>

<ol>
<li>It is vital that the electrode impedances are low, but that too much gel was not used to lower the impedance. A single bad channel can affect all the others through the common-average reference. If the impedance cannot be reduced after several tries, it is recommended that a quick-insert electrode be used, which can simply be inserted into the bad electrode through the hole that the needle is placed through for injecting the gel, and taped in place.</li>
<li>During the first session, the subject may have difficulty imagining the requ...

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		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
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<tr>
<td>BCI2000- Compatible Amplifer System</td>
<td>&nbsp;</td>
<td>g.USBamp</td>
<td>&nbsp;</td>
<td><a href="http://www.gtect.at">http://www.gtect.at</a></td>
</tr>
<tr>
<td>BCI2000- Compatible Amplifer System</td>
<td>&nbsp;</td>
<td>Tucker-Davis Technology</td>
<td>Rx5 or Rx 7</td>
<td><a href="http://www.tdt.com">http://www.tdt.com</a></td>
</tr>
<tr>
<td>EEG cap</td>
<td>&nbsp;</td>
<td>Electro-cap International</td>
<td>&nbsp;</td>
<td><a href="http://www.electro-cap.com">http://www.electro-cap.com</a> At a minimum, the cap should have electrodes over hand and feet areas (C3, C4, and Cz). Additional channels can be used for control (CP3, CP4, CPz) and for spatial filtering as well, which will improve the signal quality.</td>
</tr>
<tr>
<td>Conductive gel</td>
<td>&nbsp;</td>
<td>Electro-cap International</td>
<td>&nbsp;</td>
<td><a href="http://www.electro-cap.com">http://www.electro-cap.com</a></td>
</tr>
<tr>
<td>PC</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>Running Windows XP or Vista (at least Pentium 4, 2 GHz, 1 GB RAM)</td>
</tr>
<tr>
<td>Two monitors</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>Each at least 19in (one for the subject and one for the researcher)</td>
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using an eeg-based brain-computer interface for virtual cursor movement with bci2000

A brain-computer interface (BCI) functions by translating a neural signal, such as the electroencephalogram (EEG), into a signal that can be used to control a computer or other device. The amplitude of the EEG signals in selected frequency bins are measured and translated into a device command, in this case the horizontal and vertical velocity of a computer cursor. First, the EEG electrodes are applied to the user s scalp using a cap to record brain activity. Next, a calibration procedure is used to find the EEG electrodes and features that the user will learn to voluntarily modulate to use the BCI. In humans, the power in the mu (8-12 Hz) and beta (18-28 Hz) frequency bands decrease in amplitude during a real or imagined movement. These changes can be detected in the EEG in real-time, and used to control a BCI ([1],[2]). Therefore, during a screening test, the user is asked to make several different imagined movements with their hands and feet to determine the unique EEG features that change with the imagined movements. The results from this calibration will show the best channels to use, which are configured so that amplitude changes in the mu and beta frequency bands move the cursor either horizontally or vertically. In this experiment, the general purpose BCI system BCI2000 is used to control signal acquisition, signal processing, and feedback to the user [3].

Watch this Scientific Journal Video about Using an EEG-Based Brain-Computer Interface for Virtual Cursor Movement with BCI2000 at JoVE.com

Using an EEG-Based Brain-Computer Interface for Virtual Cursor Movement with BCI2000

In this video, we demonstrate the steps required to run a brain-computer interface experiment, including setting up the EEG cap, calibrating the system, and training the user to move a cursor in two dimensions using imagined movements.

A brain-computer interface (BCI) functions by translating a neural signal, such as the electroencephalogram (EEG), into a signal that can be used to ...

using-an-eeg-based-brain-computer-interface-for-virtual-cursor

Research

JoVE Journal

Biology

17.6K ビュー.  University of Wisconsin-Madison. このビデオでは、我々は、EEGキャップを設定するシステムのキャリブレーション、そしてユーザが想像動きを使用して、2つの次元でカーソルを移動させる訓練を含む、脳 - コンピュータインターフェースの実験を実行するために必要な手順を示しています。

ビデオ: Using an EEG-Based Brain-Computer Interface for Virtual Cursor Movement with BCI2000

In this video, we demonstrate the steps required to run a brain-computer interface experiment, including setting up the EEG cap, calibrating the system, and training the user to move a cursor in two dimensions using imagined...

p300-based brain-computer interface speller performance estimation with classifier-based latency estimation

P300-Based Brain-Computer Interface Speller Performance Estimation with Classifier-Based Latency Estimation

This article presents a method for estimating same-day P300 speller Brain-Computer Interface (BCI) accuracy using a small testing dataset.

motor imagery performance through embodied digital twins in a virtual reality-enabled brain-computer interface environment

Author Spotlight: Enhancing Neurorehabilitation Through EEG, Motor Imagery, and Virtual Reality

Motor imagery in a virtual reality environment has wide applications in brain-computer interface systems. This manuscript outlines the use of personalized digital avatars that resemble the participants performing movements imagined by the participant in a virtual reality environment to enhance immersion and a sense of body...

Motor Imagery Performance Through Embodied Digital Twins in a Virtual Reality-Enabled Brain-Computer Interface Environment

simultaneous scalp electroencephalography (eeg), electromyography (emg), and whole-body segmental inertial recording for multi-modal neural decoding

Simultaneous Scalp Electroencephalography EEG, Electromyography EMG, and Whole-body Segmental Inertial Recording for Multi-modal Neural Decoding

Development of an effective brain-machine-interface (BMI) system for restoration and rehabilitation of bipedal locomotion requires accurate decoding of user's intent.  Here we present a novel experimental protocol and data collection technique for simultaneous non-invasive acquisition of neural activity, muscle activity, and whole-body kinematics during various locomotion tasks and...

Simultaneous Scalp Electroencephalography (EEG), Electromyography (EMG), and Whole-body Segmental Inertial Recording for Multi-modal Neural Decoding

combining computer game-based behavioural experiments with high-density eeg and infrared gaze tracking

Combining Computer Game-Based Behavioural Experiments With High-Density EEG and Infrared Gaze Tracking

Procedures for recording high-density EEG and gaze data during computer game-based cognitive tasks are described.  Using a video game to present cognitive tasks enhances ecological validity without sacrificing experimental...

a single-channel and non-invasive wearable brain-computer interface for industry and healthcare

A Single-Channel and Non-Invasive Wearable Brain-Computer Interface for Industry and Healthcare

This paper discusses how to build a brain-computer interface by relying on consumer-grade equipment and steady-state visually evoked potentials. For this, a single-channel electroencephalograph exploiting dry electrodes was integrated with augmented reality glasses for stimuli presentation and output data visualization. The final system was non-invasive, wearable, and portable.

recording brain activity with electroencephalography (eeg) during the virtual spatial navigation task

Recording Brain Activity with Electroencephalography (EEG) During the Virtual Spatial Navigation Task

training and clinical evaluation of motor imagery brain-computer interface

Training and Clinical Evaluation of Motor Imagery Brain-Computer Interface

assessing human spatial navigation in a virtual space and its sensitivity to exercise

Author Spotlight: Investigating the Effects of Mind-Body-Movement Practices on Brain Function

Here, we present a novel, brief, and active spatial navigation task that assesses both spatial navigation and episodic memory ability. Importantly, spatial navigation and episodic memory were associated with one another, and this task demonstrated sensitivity to...

Game-Based Exploration: Unlocking Human Spatial Navigation Abilities

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motor imagery brain-computer interface in rehabilitation of upper limb motor dysfunction after stroke

Author Spotlight: Using Motor Imagery Brain-Computer Interface to Improve Motor and Cognitive Function in Stroke Patients

The purpose of this study is to provide an important reference for the standard clinical operation of motor imagery brain-computer interface (MI-BCI) for upper limb motor dysfunction after...

Motor Imagery Brain-Computer Interface in Rehabilitation of Upper Limb Motor Dysfunction After Stroke

evaluating flight performance and eye movement patterns using virtual reality flight simulator

Evaluating Flight Performance and Eye Movement Patterns Using Virtual Reality Flight Simulator

A new virtual reality flight simulator was built, which enables efficient and low-cost evaluation of flight performance and eye movement patterns. It also provides a high-potential research tool for ergonomics and other...

Restoring Post-Stroke Motor Function by Motor Imagery Brain-Computer Interface

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a virtual machine platform for non-computer professionals for using deep learning to classify biological sequences of metagenomic data

A Virtual Machine Platform for Non-Computer Professionals for Using Deep Learning to Classify Biological Sequences of Metagenomic Data

This tutorial describes a simple method to construct a deep learning algorithm for performing 2-class sequence classification of metagenomic...

an endoscopic transcanal transpromontorial approach for vestibular schwannomas using a computer-based three-dimensional imaging system

An Endoscopic Transcanal Transpromontorial Approach for Vestibular Schwannomas using a Computer-Based Three-Dimensional Imaging System

Here, we present a transcanal transpromontorial approach for vestibular schwannomas using a computer-based three-dimensional (3D) imaging system combined with a two-dimensional (2D) endoscope. This system provided stereoscopic vision, better depth perception and reduced visual fatigue. This 3D imaging system enabled the application of 3D vision technology in endoscopic lateral skull base...

hand controlled manipulation of single molecules via a scanning probe microscope with a 3d virtual reality interface

Hand Controlled Manipulation of Single Molecules via a Scanning Probe Microscope with a 3D Virtual Reality Interface

We demonstrate the precise manipulation of individual organic molecules on a metal surface with the tip of a scanning probe microscope driven in 3D by the experimenter's hand using a motion capture system and fully immersive virtual reality...

development of an audio-based virtual gaming environment to assist with navigation skills in the blind

Development of an Audio-based Virtual Gaming Environment to Assist with Navigation Skills in the Blind

Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the...

computer-based multitaper spectrogram program for electroencephalographic data

Computer-based Multitaper Spectrogram Program for Electroencephalographic Data

This protocol provides an open source, compiled MATLAB program that generates multitaper spectrograms for electroencephalographic...

ssvep-based experimental procedure for brain-robot interaction with humanoid robots

SSVEP-based Experimental Procedure for Brain-Robot Interaction with Humanoid Robots

The overall goal of this method is to establish an SSVEP-based experimental procedure by integrating multiple software programs to enable the study of brain-robot interaction with humanoid robots, which is prospective in assisting the sick and elderly as well as performing unsanitary or dangerous...

virtual hand with ambiguous movement between the self and other origin: sense of ownership and 'other-produced' agency

Virtual Hand with Ambiguous Movement between the Self and Other Origin: Sense of Ownership and &#039;Other-Produced&#039; Agency

While previous research on bodily self-consciousness assumed that self- and other-origin movements were perceptually distinguishable, this protocol allows them to be ambiguous on a virtual hand with unintentional slight movements. This enables us to observe one&#8217;s experience formed by SoO and other-produced SoA, rather than the absence of...

Virtual Hand with Ambiguous Movement between the Self and Other Origin: Sense of Ownership and 'Other-Produced' Agency

home-based eeg hyperscanning for infant-caregiver social interactions

Author Spotlight: Capturing Infant-Caregiver Interactions Through Synchronized Multimodal Data Collection

This protocol describes how synchronized electroencephalography, electrocardiography, and behavioral recordings were captured from infant-caregiver dyads in a home...

Home-Based EEG Hyperscanning for Infant-Caregiver Social Interactions

Testing Nicotine Tolerance in Aphids Using an Artificial Diet Experiment

Plants may upregulate the production of many different seconday metabolites in response to insect feeding. One of these metabolites, nicotine, is well know to have insecticidal properties. One response of tobacco plants to herbivory, or being gnawed upon by insects, is to increase the production of this neurotoxic alkaloid. Here, we will demonstrate how to set up an experiment to address this question of whether a tobacco-adapted strain of the green peach aphid, Myzus persicae, can tolerate higher levels of nicotine than the a strain of this insect that does not infest tobacco in the field.

In this video and assay is demonstrated that tests the tolerance of nicotine to two types of aphids one that infests tobacco plants in the field and one that does not.

Plants may upregulate the production of many different seconday metabolites in response to insect feeding. One of these metabolites, nicotine, is well ...

Interview: HIV-1 Proviral DNA Excision Using an Evolved Recombinase

HIV-1 integrates into the host chromosome of infected cells and persists as a provirus flanked by long terminal repeats. Current treatment strategies primarily target virus enzymes or virus-cell fusion, suppressing the viral life cycle without eradicating the infection. Since the integrated provirus is not targeted by these approaches, new resistant strains of HIV-1 may emerge. Here, we report that the engineered recombinase Tre (see Molecular evolution of the Tre recombinase , Buchholz, F., Max Planck Institute for Cell Biology and Genetics, Dresden) efficiently excises integrated HIV-1 proviral DNA from the genome of infected cells. We produced loxLTR containing viral pseudotypes and infected HeLa cells to examine whether Tre recombinase can excise the provirus from the genome of HIV-1 infected human cells. A virus particle-releasing cell line was cloned and transfected with a plasmid expressing Tre or with a parental control vector. Recombinase activity and virus production were monitored. All assays demonstrated the efficient deletion of the provirus from infected cells without visible cytotoxic effects. These results serve as proof of principle that it is possible to evolve a recombinase to specifically target an HIV-1 LTR and that this recombinase is capable of excising the HIV-1 provirus from the genome of HIV-1-infected human cells.
Before an engineered recombinase could enter the therapeutic arena, however, significant obstacles need to be overcome. Among the most critical issues, that we face, are an efficient and safe delivery to targeted cells and the absence of side effects.

Current HIV-1 strategies act to suppress the viral life cycle but do not effectively eradicate infection. Here, we demonstrate that an engineered recombinase can efficiently excise integrated HIV-1 proviral DNA from the genome of infected cells.

HIV-1 integrates into the host chromosome of infected cells and persists as a provirus flanked by long terminal repeats. Current treatment strategies ...

The Structure of Skilled Forelimb Reaching in the Rat: A Movement Rating Scale

Skilled reaching for food is an evolutionary ancient act and is displayed by many animal species, including those in the sister clades of rodents and primates. The video describes a test situation that allows filming of repeated acts of reaching for food by the rat that has been mildly food deprived. A rat is trained to reach through a slot in a holding box for food pellet that it grasps and then places in its mouth for eating. Reaching is accomplished in the main by proximally driven movements of the limb but distal limb movements are used for pronating the paw, grasping the food, and releasing the food into the mouth. Each reach is divided into at least 10 movements of the forelimb and the reaching act is facilitated by postural adjustments. Each of the movements is described and examples of the movements are given from a number of viewing perspectives. By rating each movement element on a 3-point scale, the reach can be quantified. A number of studies have demonstrated that the movement elements are altered by motor system damage, including damage to the motor cortex, basal ganglia, brainstem, and spinal cord. The movements are also altered in neurological conditions that can be modeled in the rat, including Parkinson's disease and Huntington's disease. Thus, the rating scale is useful for quantifying motor impairments and the effectiveness of neural restoration and rehabilitation. Because the reaching act for the rat is very similar to that displayed by humans and nonhuman primates, the scale can be used for comparative purposes. from a number of viewing perspectives. By rating each movement element on a 3-point scale, the reach can be quantified. A number of studies have demonstrated that the movement elements are altered by motor system damage, including damage to the motor cortex, basal ganglia, brainstem, and spinal cord. The movements are also altered in neurological conditions that can be modeled in the rat, including Parkinson's disease and Huntington's disease. Thus, the rating scale is useful for quantifying motor impairments and the effectiveness of neural restoration and rehabilitation.

Experiments on animals were performed in accordance with the guidelines and regulations set forth by the University of Lethbridge Animal Care Committee in accordance with the regulations of the Canadian Council on Animal Care.

The skilled reaching scale divides the movement by a forelimb in a reach for food act into composite elements each of which are evaluated with a three-point scale. The rating scale is described for a normal rat and can be applied toward evaluating neurological motor disorders.

Skilled reaching for food is an evolutionary ancient act and is displayed by many animal species, including those in the sister clades of rodents and ...

The use of Biofeedback in Clinical Virtual Reality: The INTREPID Project

Generalized anxiety disorder (GAD) is a psychiatric disorder characterized by a constant and unspecific anxiety that interferes with daily-life activities. Its high prevalence in general population and the severe limitations it causes, point out the necessity to find new efficient strategies to treat it. Together with the cognitive-behavioral treatments, relaxation represents a useful approach for the treatment of GAD, but it has the limitation that it is hard to be learned. The INTREPID project is aimed to implement a new instrument to treat anxiety-related disorders and to test its clinical efficacy in reducing anxiety-related symptoms. The innovation of this approach is the combination of virtual reality and biofeedback, so that the first one is directly modified by the output of the second one. In this way, the patient is made aware of his or her reactions through the modification of some features of the VR environment in real time. Using mental exercises the patient learns to control these physiological parameters and using the feedback provided by the virtual environment is able to gauge his or her success. The supplemental use of portable devices, such as PDA or smart-phones, allows the patient to perform at home, individually and autonomously, the same exercises experienced in therapist's office. The goal is to anchor the learned protocol in a real life context, so enhancing the patients' ability to deal with their symptoms. The expected result is a better and faster learning of relaxation techniques, and thus an increased effectiveness of the treatment if compared with traditional clinical protocols.

The Project on Virtual Reality Intelligent Multi-sensor System for the Treatment of Anxiety-related Disorders (INTREPID) is aimed at developing a multi-sensor context-aware virtual reality system for the treatment of anxiety-related disorders.

Generalized anxiety disorder (GAD) is a psychiatric disorder characterized by a constant and unspecific anxiety that interferes with daily-life ...

Measuring the Bending Stiffness of Bacterial Cells Using an Optical Trap

We developed a protocol to measure the bending rigidity of filamentous rod-shaped bacteria. Forces are applied with an optical trap, a microscopic three-dimensional spring made of light that is formed when a high-intensity laser beam is focused to a very small spot by a microscope's objective lens. To bend a cell, we first bind live bacteria to a chemically-treated coverslip. As these cells grow, the middle of the cells remains bound to the coverslip but the growing ends are free of this restraint. By inducing filamentous growth with the drug cephalexin, we are able to identify cells in which one end of the cell was stuck to the surface while the other end remained unattached and susceptible to bending forces. A bending force is then applied with an optical trap by binding a polylysine-coated bead to the tip of a growing cell. Both the force and the displacement of the bead are recorded and the bending stiffness of the cell is the slope of this relationship.

We present a protocol for bending filamentous bacterial cells attached to a cover-slip surface with an optical trap to measure the cellular bending stiffness.

We developed a protocol to measure the bending rigidity of filamentous rod-shaped bacteria. Forces are applied with an optical trap, a microscopic ...

Culturing of Human Nasal Epithelial Cells at the Air Liquid Interface

In vitro models using human primary epithelial cells are essential in understanding key functions of the respiratory epithelium in the context of microbial infections or inhaled agents. Direct comparisons of cells obtained from diseased populations allow us to characterize different phenotypes and dissect the underlying mechanisms mediating changes in epithelial cell function. Culturing epithelial cells from the human tracheobronchial region has been well documented, but is limited by the availability of human lung tissue or invasiveness associated with obtaining the bronchial brushes biopsies. Nasal epithelial cells are obtained through much less invasive superficial nasal scrape biopsies and subjects can be biopsied multiple times with no significant side effects. Additionally, the nose is the entry point to the respiratory system and therefore one of the first sites to be exposed to any kind of air-borne stressor, such as microbial agents, pollutants, or allergens. 
Briefly, nasal epithelial cells obtained from human volunteers are expanded on coated tissue culture plates, and then transferred onto cell culture inserts. Upon reaching confluency, cells continue to be cultured at the air-liquid interface (ALI), for several weeks, which creates more physiologically relevant conditions. The ALI culture condition uses defined media leading to a differentiated epithelium that exhibits morphological and functional characteristics similar to the human nasal epithelium, with both ciliated and mucus producing cells. Tissue culture inserts with differentiated nasal epithelial cells can be manipulated in a variety of ways depending on the research questions (treatment with pharmacological agents, transduction with lentiviral vectors, exposure to gases, or infection with microbial agents) and analyzed for numerous different endpoints ranging from cellular and molecular pathways, functional changes, morphology, etc. 
In vitro models of differentiated human nasal epithelial cells will enable investigators to address novel and important research questions by using organotypic experimental models that largely mimic the nasal epithelium in vivo.

Nasal epithelial cells, obtained through superficial scrape biopsy of human volunteers, are expanded and transferred onto tissue culture inserts. Upon reaching confluency, cells are grown at air liquid interface, yielding cultures of ciliated and non-ciliated cells. Differentiated nasal epithelial cell cultures provide viable experimental models for studying the respiratory mucosa.

In vitro models using human primary  epithelial cells are essential in understanding key functions of the respiratory  epithelium in the context of ...

Nanopodia - Thin, Fragile Membrane Projections with Roles in Cell Movement and Intercellular Interactions

Adherent cells in culture maintain a polarized state to support movement and intercellular interactions. Nanopodia are thin, elongated, largely F-actin-negative membrane projections in endothelial and cancer cells that can be visualized through TM4SF1 (Transmembrane-4-L-six-family-1) immunofluorescence staining. TM4SF1 clusters in 100-300 &#956;m diameter TMED (TM4SF1 enriched microdomains) containing 3 to as many as 14 individual TM4SF1 molecules. TMED are arranged intermittently along nanopodia at a regular spacing of 1 to 3 TMED per &#956;m and firmly anchor nanopodia to matrix. This enables nanopodia to extend more than 100 &#956;m from the leading front or trailing rear of polarized endothelial or tumor cells, and causes membrane residues to be left behind on matrix when the cell moves away. TMED and nanopodia have been overlooked because of their extreme fragility and sensitivity to temperature. Routine washing and fixation disrupt the structure. Nanopodia are preserved by direct fixation in paraformaldehyde (PFA) at 37 &#176;C, followed by brief exposure to 0.01% Triton X-100 before staining. Nanopodia open new vistas in cell biology: they promise to reshape our understanding of how cells sense their environment, detect and identify other cells at a distance, initiate intercellular interactions at close contact, and of the signaling mechanisms involved in movement, proliferation, and cell-cell communications. The methods that are developed for studying TM4SF1-derived nanopodia may be useful for studies of nanopodia that form in other cell types through the agency of classic tetraspanins, notably the ubiquitously expressed CD9, CD81, and CD151.

Nanopodia are thin but fragile membrane channels that extend up to 100 &#956;m from a cell's leading front or trailing rear and sense the cellular environment. Direct fixation at 37 &#176;C, gentle washing, and avoidance of organic solvents like ethanol, methanol, or acetone and of higher Triton X-100 concentrations are required to observe these cellular structures.

Adherent cells in culture maintain a polarized state to support movement and intercellular interactions. Nanopodia are thin, elongated, largely ...

An Alternative Approach for Sample Preparation with Low Cell Number for TEM Analysis

Transmission electron microscopy (TEM) provides details of the cellular organization and ultrastructure. However, TEM analysis of rare cell populations, especially cells in suspension such as hematopoietic stem cells (HSCs), remains limited due to the requirement of a high cell number during sample preparation. There are a few cytospin or monolayer approaches for TEM analysis from scarce samples, but these approaches fail to get significant quantitative data from the limited number of cells. Here, an alternative and novel approach for sample preparation in TEM studies is described for rare cell populations that enables quantitative analysis.
A relatively low cell number, i.e., 10,000 HSCs, was successfully used for TEM analysis compared to the millions of cells typically used for TEM studies. In particular, Evans blue staining was performed after paraformaldehyde-glutaraldehyde (PFA-GA) fixation to visualize the tiny cell pellet, which facilitated embedding in agarose. Clusters of numerous cells were observed in ultra-thin sections. The cells had a well preserved morphology, and the ultra-structural details of the Golgi complex and several mitochondria were visible. This efficient, easy and reproducible protocol allows sample preparation from a low cell number and can be used for qualitative and quantitative TEM analysis on rare cell populations from limited biological samples.

Here, we present a protocol to prepare samples with low cell numbers for transmission electron microscopy (TEM) analysis.

Transmission electron microscopy (TEM) provides details of the cellular organization and ultrastructure. However, TEM analysis of rare cell populations, ...

Visualization of 3D White Adipose Tissue Structure Using Whole-mount Staining

Adipose tissue is an important metabolic organ with high plasticity and is responsive to environmental stimuli and nutrient status. As such, various techniques have been developed to study the morphology and biology of adipose tissue. However, conventional visualization methods are limited to studying the tissue in 2D sections, failing to capture the 3D architecture of the whole organ. Here we present whole-mount staining, an immunohistochemistry method that preserves intact adipose tissue morphology with minimal processing steps. Hence, the structures of adipocytes and other cellular components are maintained without distortion, achieving the most representative 3D visualization of the tissue. In addition, whole-mount staining can be combined with lineage tracing methods to determine cell fate decisions. However, this technique has some limitations to providing accurate information regarding deeper parts of adipose tissue. To overcome this limitation, whole-mount staining can be further combined with tissue clearing techniques to remove the opaqueness of tissue and allow for complete visualization of entire adipose tissue anatomy using light-sheet fluorescent microscopy. Therefore, a higher resolution and more accurate representation of adipose tissue structures can be captured with the combination of these techniques.

The focus of the present study is to demonstrate the whole-mount immunostaining and visualization technique as an ideal method for 3D imaging of adipose tissue architecture and cellular component.

Adipose tissue is an important metabolic organ with high plasticity and is responsive to environmental stimuli and nutrient status. As such, various ...

Single Cell Durotaxis Assay for Assessing Mechanical Control of Cellular Movement and Related Signaling Events

Durotaxis is the process by which cells sense and respond to gradients of tension. In order to study this process in vitro, the stiffness of the substrate underlying a cell must be manipulated. While hydrogels with graded stiffness and long-term migration assays have proven useful in durotaxis studies, immediate, acute responses to local changes in substrate tension allow focused study of individual cell movements and subcellular signaling events. To repeatably test the ability of cells to sense and respond to the underlying substrate stiffness, a modified method for application of acute gradients of increased tension to individual cells cultured on deformable hydrogels is used which allows for real time manipulation of the strength and direction of stiffness gradients imparted upon cells in question. Additionally, by fine tuning the details and parameters of the assay, such as the shape and dimensions of the micropipette or the relative position, placement, and direction of the applied gradient, the assay can be optimized for the study of any mechanically sensitive cell type and system. These parameters can be altered to reliably change the applied stimulus and expand the functionality and versatility of the assay. This method allows examination of both long term durotactic movement as well as more immediate changes in cellular signaling and morphological dynamics in response to changing stiffness.

Mechanical forces are important for controlling cell migration. This protocol demonstrates the use of elastic hydrogels that can be deformed using a glass micropipette and a micromanipulator to stimulate cells with a local stiffness gradient to elicit changes in cell structure and migration.

Durotaxis is the process by which cells sense and respond to gradients of tension. In order to study this process in vitro, the stiffness of the substrate ...