This work was supported by grants to L.A.P. (P.I.):
National Institutes of Health R21 HD50558, awarded 2005-07; National
Institutes of Health R01 HD045822, awarded 2004-09; Dana Foundation Grant,
awarded 2004-06; Canadian Foundation for Innovation ("CFI" grant), awarded
2008-2012; The Ontario Research Fund Grant, awarded 2008-2012.

Part 1: Prior to participant arriving to the lab
<ol>
<li>Ensure that the room is free of extraneous articles that may be distracting to the participant.</li>
<li>Set-up and load experimental protocol on the fNIRS Hitachi ETG-4000 system.</li>
<li>Set-up your experimental paradigm. Experimental paradigms can be programmed with different presentation software, including Eprime, Presentation, Psyscope or a Matlab based psychology toolbox. Here we use Matlab based psychology toolbox. </li>
<li>Timing is key for data analysis, thus the experimental paradigm must be perfectly timed with data collection. The fNIRS Hitachi ETG-4000 has triggering capabilities, allowing for the experimental paradigm to trigger the data collection or vice versa. Test triggering of presentation program from fNIRS Hitachi ETG-4000. Triggering can be done using parallel, serials, or USB ports. Here we show triggering via the parallel port.</li>
<li>Prior to starting the fNIRS study it is important to conduct participant background screening. In the Petitto lab, we conduct background screening by having the participants or their parents fill out study-appropriate standardized questionnaires29.</li>
</ol>
Participant Arrives
<ol start="6">
<li>It is important to conduct the session and to treat the participants in a professional manner. The participant or the participants' parents/legal guardians must sign a consent form before the experiment begins. It is vital to thank the participant for their time in these important and exciting experiments.</li>
<li>The participant is seated comfortably close to the fNIRS testing room. An infant participant may be seated on a parent's lap.</li>
</ol>
Part 2: Placing Optodes &amp; Using the 10-20 system
Another component of the analysis method that enables consistent data interpretation is the standardization of fNIRS recording protocol. This entails optode placement, participant positioning, and triggering of stimulus presentation software. Both the accurate neuro-anatomical placement of probes and the confirmation of regions of interest (ROIs) are achieved by using the 10&ndash;20 system3,4,30. Further, stereotactic localization of the probe array was confirmed on the participant's skull by overlaying 3D tracking information from a Polhemus Fast trak system onto an anatomical MRI co-registration scan of the participant conducted with vitamin E capsules placed at each probe location3,4.Optimal participant positioning involved placing participants comfortably in a reclining chair, with fiber optics hanging loosely without contact with the body or chair.
<ol>
<li>The following head measurements are taken with a tape measure and written down on the participants data sheet: 
<ul>
<li>Nasion to Inion around</li>
<li>Nasion to Inions over top</li>
<li>Ear to Ear over top</li>
</ul>
</li>
<li>Surgical tape can be used to mark specific target locations. In this experiment we will mark Fp, T3/T4, F8/F7</li>
<li>Optode arrays are placed on the participants' head with specific optodes anchored at 10-20 points as directed by the purposes of the experiment.</li>
</ol>
Part 4: Testing the Optode Array
<ol>
<li>Introduction to the Hitachi ETG-4000 GUI Interface and probe testing.</li>
<li>Testing signal: Once optodes are placed on the participants' scalp, the signal quality is tested. If an optode does not have a clear signal, researchers gently remove hair from the connection of the optode and the scalp. On occasion the optodes may need to be wiped with an alcohol swab.</li>
</ol>
Part 5: Running the experiment.
<ol>
<li>At least two experimenters must be always present in the room; one observing the fNIRS Hitachi ETG-4000 real-time read out and the other observing the participant. Having a video camera focused on participant is highly recommended for post-hoc observations. An advantage of the fNIRS Hitachi ETG-4000 is that the video and fNIRS signal are synched and co-registered. A log containing all relevant information and files generated is kept.</li>
<li>There are well-established methods of building experimental hemodynamic paradigms, namely Block design and Event-related designs. For a more complete description please see the recent review paper31.</li>
</ol>
Part 6: Analysis
Once all of the data have been collected, the participant is thanked for their time and willingness to participate and leaves the lab. As analysis is not done on the fNIRS Hitachi ETG-4000, as, instead, the data are exported to an analysis computer.
<ol>
<li>Conversion from &mu;V to hemoglobin concentrations. As raw attenuation values are collected in attenuation of laser strength (as measured in &mu;V), these values must be converted to oxygenated and deoxygenated hemoglobin values. This is done using the modified Beer-Lambert equation.</li>
<li>The application of the modified Beer-Lambert is conducted in two steps. Under the assumption that scattering is constant over the path length, first the attenuation for each wavelength (&Delta;A&lambda;(t)) is calculated by comparing the optical density of light intensity during the task (Itask) to the calculated baseline of the signal (Ibaseline). The &Delta;A values for each wavelength and sampled time point (t) to solve the modified Beer-Lambert equation. 
<table border="0">
<tbody>
<tr>
<td>Equation 1<img style="float:left;" src="/files/ftp_upload/1268/eq1.jpg" alt="equation 1" /></td>
<td>Equation 2<img style="float:left;" src="/files/ftp_upload/1268/eq2.jpg" alt="equation 2" /></td>
</tr>
</tbody>
</table>
</li>
</ol>
&lambda;1&isin;deoxy, &lambda;1&isin;oxy, &lambda;2&isin;deoxy and &lambda; 2&isin;oxy are the constants for the extinction coefficients that measure the fraction of light lost to absorption per unit concentration distance in the tissue. The resultant Cdeoxy and Coxy values are the concentrations of deoxygenated and oxygenated hemoglobin for each t.
Part 7: Representative Results
Typical hemodynamic response results in several distinct characteristics. In the oxy-hemoglobin response, there is first a characteristic dip. This dip occurs as a region of neurons activates and depletes available oxygen. As blood flow increases, carrying oxygenated hemoglobin, the oxy-hemoglobin response rises rapidly above the initial baseline levels to a steady state level. When the region is no longer being activated, the oxy-hemoglobin response decays over the next 12-15 seconds and slowly drops back to baseline levels. There is occasionally an undershoot that occurs prior to the hemodynamic response returning to initial baseline levels.
Bad results are usually in the form of optodes not properly seated on the scalp or excessive movement. These types of noise &ndash; called, 'Flatling' &ndash; are evident in the signal as the microvolt values saturate and a number of different channels, both oxy- and deoxy- response move in a coordinated fashion.
DEMONSTRATION: Shaking the fiber optics.
Statistical Analyses: The extracted oxy and deoxy-hemoglobin values for each channel, for each participant and for each task can then be submitted to conventional statistical analysis, including t-tests, ANOVAs, correlations etc.

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Lett. 256, 49-52 (1998).</li><li>Kovelman, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> NeuroImage. 39, 1457-1471 (2008).</li><li>Kovelman, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Brain and Language. , (2008).</li><li>Bortfeld, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Developmental Neuropsychology. 34, 52-65 (2009).</li><li>Petitto, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Cambridge Companion to Chomsky. , (2005).</li><li>Berens, M. 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Cogn.. 61, 189-194 (2006).</li><li>Grignon, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Cognitive and Behavioral Neurology. 21, 41-45 (2008).</li><li>Boas, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Neuroimage. 23, S275-S288 (2004).</li><li>Aslin, R. N., Mehler, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> J. of Biomed. Opt.. , 1-3 (2005).</li><li>Plichta, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> NeuroImage. 35, 625-634 (2007).</li><li>Schroeter, M. 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Neurophysiol. 10, 370-371 (1958).</li><li>Amaro, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Brain Cogn. 60, 220-232 (2006).</li></ol>

The authors have nothing to disclose.

In this study, we demonstrated the use of a novel, non-invasive fNIRS brain imaging technology to investigate human brain function in relation to human cognition and perception. fNIRS brain imaging may represent the future of non-invasive brain imaging, particularly with infant and child populations, that may one day be widely available in research labs, physicians' offices, and in the school systems allowing clinicians to apply basic scientific findings about the brain to their clinical practice.

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<td>ETG-4000</td>
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exploring cognitive functions in babies, children &amp; adults with near infrared spectroscopy

An explosion of functional Near Infrared Spectroscopy (fNIRS) studies investigating cortical activation in relation to higher cognitive processes, such as language1,2,3,4,5,6,7,8,9,10, memory11, and attention12 is underway worldwide involving adults, children and infants 3,4,13,14,15,16,17,18,19 with typical and atypical cognition20,21,22. The contemporary challenge of using fNIRS for cognitive neuroscience is to achieve systematic analyses of data such that they are universally interpretable23,24,25,26, and thus may advance important scientific questions about the functional organization and neural systems underlying human higher cognition.
Existing neuroimaging technologies have either less robust temporal or spatial resolution. Event Related Potentials and Magneto Encephalography (ERP and MEG) have excellent temporal resolution, whereas Positron Emission Tomography and functional Magnetic Resonance Imaging (PET and fMRI) have better spatial resolution. Using non-ionizing wavelengths of light in the near-infrared range (700-1000 nm), where oxy-hemoglobin is preferentially absorbed by 680 nm and deoxy-hemoglobin is preferentially absorbed by 830 nm (e.g., indeed, the very wavelengths hardwired into the fNIRS Hitachi ETG-400 system illustrated here), fNIRS is well suited for studies of higher cognition because it has both good temporal resolution (~5s) without the use of radiation and good spatial resolution (~4 cm depth), and does not require participants to be in an enclosed structure27,28. Participants cortical activity can be assessed while comfortably seated in an ordinary chair (adults, children) or even seated in mom s lap (infants). Notably, NIRS is uniquely portable (the size of a desktop computer), virtually silent, and can tolerate a participants subtle movement. This is particularly outstanding for the neural study of human language, which necessarily has as one of its key components the movement of the mouth in speech production or the hands in sign language. 
The way in which the hemodynamic response is localized is by an array of laser emitters and detectors. Emitters emit a known intensity of non-ionizing light while detectors detect the amount reflected back from the cortical surface. The closer together the optodes, the greater the spatial resolution, whereas the further apart the optodes, the greater depth of penetration. For the fNIRS Hitachi ETG-4000 system optimal penetration / resolution the optode array is set to 2cm. 
Our goal is to demonstrate our method of acquiring and analyzing fNIRS data to help standardize the field and enable different fNIRS labs worldwide to have a common background.

Watch this Scientific Journal Video about Exploring Cognitive Functions in Babies, Children & Adults with Near Infrared Spectroscopy at JoVE.com

Exploring Cognitive Functions in Babies, Children &amp; Adults with Near Infrared Spectroscopy

Here we describe a data collection and data analysis method for functional Near Infrared Spectroscopy (fNIRS), a novel non-invasive brain imaging system used in cognitive neuroscience, particularly in studying child brain development. This method provides a universal standard of data acquisition and analysis vital to data interpretation and scientific discovery.

An explosion of functional Near Infrared Spectroscopy (fNIRS) studies investigating cortical activation in relation to higher cognitive processes, such as ...

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20.4K vistas.  University of Michigan, Ann Arbor. Aquí se describe un método de recolección de datos y análisis de datos para funcionales espectroscopia de infrarrojo cercano (fNIRS), una novela de sistema no invasivo usa imágenes del cerebro en la neurociencia cognitiva, especialmente en el estudio del desarrollo del cerebro del niño. Este método proporciona un estándar universal de adquisición de datos y el análisis fundamental para la interpretación de datos y descubrimientos científicos.

Video: Exploring Cognitive Functions in Babies, Children & Adults with Near Infrared Spectroscopy

Recordings of Neural Circuit Activation in Freely Behaving Animals

The relationship between patterns of neural activity and corresponding behavioral expression is difficult to establish in unrestrained animals. Traditional non-invasive methods require at least partially restrained research subjects, and they only allow identification of large numbers of simultaneously activated neurons. On the other hand, small ensembles of neurons or individual neurons can only be measured using single-cell recordings obtained from largely reduced preparations. Since the expression of natural behavior is limited in restrained and dissected animals, the underlying neural mechanisms that control such behavior are difficult to identify. 
Here, I present a non-invasive physiological technique that allows measuring neural circuit activation in freely behaving animals. Using a pair of wire electrodes inside a water-filled chamber, the bath electrodes record neural and muscular field potentials generated by juvenile crayfish during natural or experimentally evoked escape responses. The primary escape responses of crayfish are mediated by three different types of tail-flips which move the animals away from the point of stimulation. Each type of tail-flip is controlled by its own neural circuit; the two fastest and most powerful escape responses require activation of different sets of large &#8220;command&#8221; neurons. In combination with behavioral observations, the bath electrode recordings allow unambiguous identification of these neurons and the associated neural circuits. Thus activity of neural circuitry underlying naturally occurring behavior can be measured in unrestrained animals and in different behavioral contexts.

Non-invasive measurements of neural activity patterns in freely behaving animals are obtained by combining neurophysiological recordings with high speed videography.

The relationship between patterns of neural activity and corresponding behavioral expression is difficult to establish in unrestrained animals. ...

Assembly, Tuning and Use of an Apertureless Near Field Infrared Microscope for Protein Imaging

This paper aims to instruct the reader in the assembly and operation of an infrared near-field microscope for imaging beyond the diffraction limit.  The apertureless near-field microscope is a light scattering-type instrument that provides infrared spectra at circa 20 nm resolution. A complete list of components and a step-by-step protocol for use is provided.  Common errors in assembly and instrument tuning are discussed.  A representative data set that shows the secondary structure of an amyloid fibril is presented.  

The assembly of a nearfield infrared microscope for imaging protein aggregates is described.

This paper aims to instruct the reader in the assembly and operation of an infrared near-field microscope for imaging beyond the diffraction limit.  The ...

Measurement Of Neuromagnetic Brain Function In Pre-school Children With Custom Sized MEG

Magnetoencephalography is a technique that detects magnetic fields associated with cortical activity [1]. The electrophysiological activity of the brain generates electric fields  - that can be recorded using electroencephalography (EEG)- and their concomitant magnetic fields  - detected by MEG. MEG signals are detected by specialized sensors known as superconducting quantum interference devices (SQUIDs). Superconducting sensors require cooling with liquid helium at -270 &deg;C. They are contained inside a vacumm-insulated helmet called a dewar, which is filled with liquid. SQUIDS are placed in fixed positions inside the helmet dewar in the helium coolant, and a subject's head is placed inside the helmet dewar for MEG measurements. The helmet dewar must be sized to satisfy opposing constraints. Clearly, it must be large enough to fit most or all of the heads in the population that will be studied. However, the helmet must also be small enough to keep most of the SQUID sensors within range of the tiny cerebral fields that they are to measure. Conventional whole-head MEG systems are designed to accommodate more than 90% of adult heads. However adult systems are not well suited for measuring brain function in pre-school chidren whose heads have a radius several cm smaller than adults. The KIT-Macquarie Brain Research Laboratory at Macquarie University uses a MEG system custom sized to fit the heads of pre-school children. This child system has 64 first-order axial gradiometers with a 50 mm baseline[2] and is contained inside a magnetically-shielded room (MSR) together with a conventional adult-sized MEG system [3,4]. There are three main advantages of the customized helmet dewar for studying children. First, the smaller radius of the sensor configuration brings the SQUID sensors into range of the neuromagnetic signals of children's heads. Second, the smaller helmet allows full insertion of a child's head into the dewar. Full insertion is prevented in adult dewar helmets because of the smaller crown to shoulder distance in children. These two factors are fundamental in recording brain activity using MEG because neuromagnetic signals attenuate rapidly with distance. Third, the customized child helmet aids in the symmetric positioning of the head and limits the freedom of movement of the child's head within the dewar. When used with a protocol that aligns the requirements of data collection with the motivational and behavioral capacities of children, these features significantly facilitate setup, positioning, and measurement of MEG signals.

The advent of MEG systems sized for young children opens important new opportunities to study brain development. The new system, together with a protocol that aligns experimental requirements with the capacities of children, can be used to study cognitive and language processes in healthy, awake children aged three to six.

Magnetoencephalography is a technique that detects magnetic fields associated with cortical activity [1]. The electrophysiological activity of the brain ...

Method for the Assessment of Effects of a Range of Wavelengths and Intensities of Red/near-infrared Light Therapy on Oxidative Stress In Vitro

Red/near-infrared light therapy (R/NIR-LT), delivered by laser or light emitting diode (LED), improves functional and morphological outcomes in a range of central nervous system injuries in vivo, possibly by reducing oxidative stress. However, effects of R/NIR-LT on oxidative stress have been shown to vary depending on wavelength or intensity of irradiation. Studies comparing treatment parameters are lacking, due to absence of commercially available devices that deliver multiple wavelengths or intensities, suitable for high through-put in vitro optimization studies. This protocol describes a technique for delivery of light at a range of wavelengths and intensities to optimize therapeutic doses required for a given injury model. We hypothesized that a method of delivering light, in which wavelength and intensity parameters could easily be altered, could facilitate determination of an optimal dose of R/NIR-LT for reducing reactive oxygen species (ROS) in vitro.
Non-coherent Xenon light was filtered through narrow-band interference filters to deliver varying wavelengths (center wavelengths of 440, 550, 670 and 810nm) and fluences (8.5 x 10-3 to 3.8 x 10-1 J/cm2) of light to cultured cells. Light output from the apparatus was calibrated to emit therapeutically relevant, equal quantal doses of light at each wavelength. Reactive species were detected in glutamate stressed cells treated with the light, using DCFH-DA and H2O2 sensitive fluorescent dyes.&#160;
We successfully delivered light at a range of physiologically and therapeutically relevant wavelengths and intensities, to cultured cells exposed to glutamate as a model of CNS injury. While the fluences of R/NIR-LT used in the current study did not exert an effect on ROS generated by the cultured cells, the method of light delivery is applicable to other systems including isolated mitochondria or more physiologically relevant organotypic slice culture models, and could be used to assess effects on a range of outcome measures of oxidative metabolism.

Method for the Assessment of Effects of a Range of Wavelengths and Intensities of Red/near-infrared Light Therapy on Oxidative Stress In Vitro

Non-coherent Xenon light was passed through narrow-band interference and neutral density filters to deliver light of varying wavelength and intensity to cultured cells. This protocol was used to assess the effects of red/near-infrared light therapy on production of reactive species in vitro: no effects were observed using the tested parameters.

Red/near-infrared light therapy (R/NIR-LT), delivered by laser or light emitting diode (LED), improves functional and morphological outcomes in a range of ...

Near Infrared (NIr) Light Increases Expression of a Marker of Mitochondrial Function in the Mouse Vestibular Sensory Epithelium

Strategies for attenuating decline in balance function with increasing age are predominantly focused on physical therapies including balance tasks and exercise. However, these approaches do not address the underlying causes of balance decline. Using mice, the impact of near infrared light (NIr) on the metabolism of cells in the vestibular sensory epithelium was assessed. Data collected shows that this simple and safe intervention may protect these vulnerable cells from the deleterious effects of natural aging. mRNA was extracted from the isolated peripheral vestibular sensory epithelium (crista ampullaris and utricular macula) and subsequently transcribed into a cDNA library. This library was then probed for the expression of ubiquitous antioxidant (SOD-1). Antioxidant gene expression was then used to quantify cellular metabolism. Using transcranial delivery of NIr in young (4 weeks) and older (8 - 9 months) mice, and a brief treatment regime (90 sec/day for 5 days), this work suggests NIr alone may be sufficient to improve mitochondrial function in the vestibular sensory epithelium. Since there are currently no available, affordable, non-invasive methods of therapy to improve vestibular hair cell function, the application of external NIr radiation provides a potential strategy to counteract the impact of aging on cellular metabolism inthe vestibular sensory epithelium.

Near Infrared NIr Light Increases Expression of a Marker of Mitochondrial Function in the Mouse Vestibular Sensory Epithelium

Mitochondrial dysfunction is a hallmark of cellular senescence. This paper uses non-invasive near-infrared (NIr) treatment to improve mitochondrial function in the aging mouse vestibular sensory epithelium.

Strategies for attenuating decline in balance function with increasing age are predominantly focused on physical therapies including balance tasks and ...

Functional Reconstitution and Channel Activity Measurements of Purified Wildtype and Mutant CFTR Protein

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a unique channel-forming member of the ATP Binding Cassette (ABC) superfamily of transporters. The phosphorylation and nucleotide dependent chloride channel activity of CFTR has been frequently studied in whole cell systems and as single channels in excised membrane patches. Many Cystic Fibrosis-causing mutations have been shown to alter this activity. While a small number of purification protocols have been published, a fast reconstitution method that retains channel activity and a suitable method for studying population channel activity in a purified system have been lacking. Here rapid methods are described for purification and functional reconstitution of the full-length CFTR protein into proteoliposomes of defined lipid composition that retains activity as a regulated halide channel. This reconstitution method together with a novel flux-based assay of channel activity is a suitable system for studying the population channel properties of wild type CFTR and the disease-causing mutants F508del- and G551D-CFTR. Specifically, the method has utility in studying the direct effects of phosphorylation, nucleotides and small molecules such as potentiators and inhibitors on CFTR channel activity. The methods are also amenable to the study of other membrane channels/transporters for anionic substrates.

Described here is a rapid and effective procedure for functional reconstitution of purified wild-type and mutant CFTR protein that preserves activity for this chloride channel, which is defective in Cystic Fibrosis. Iodide efflux from reconstituted proteoliposomes mediated by CFTR allows studies of channel activity and the effects of small molecules.

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a unique channel-forming member of the ATP Binding Cassette (ABC) superfamily of ...

The ChIP-exo Method: Identifying Protein-DNA Interactions with Near Base Pair Precision

Chromatin immunoprecipitation (ChIP) is an indispensable tool in the fields of epigenetics and gene regulation that isolates specific protein-DNA interactions. ChIP coupled to high throughput sequencing (ChIP-seq) is commonly used to determine the genomic location of proteins that interact with chromatin. However, ChIP-seq is hampered by relatively low mapping resolution of several hundred base pairs and high background signal. The ChIP-exo method is a refined version of ChIP-seq that substantially improves upon both resolution and noise. The key distinction of the ChIP-exo methodology is the incorporation of lambda exonuclease digestion in the library preparation workflow to effectively footprint the left and right 5&#39; DNA borders of the protein-DNA crosslink site. The ChIP-exo libraries are then subjected to high throughput sequencing. The resulting data can be leveraged to provide unique and ultra-high resolution insights into the functional organization of the genome. Here, we describe the ChIP-exo method that we have optimized and streamlined for mammalian systems and next-generation sequencing-by-synthesis platform.

Here, we present a protocol to achieve near base pair resolution of protein-DNA interactions. This is obtained by exonuclease treatment of DNA fragments selectively enriched by chromatin immunoprecipitation (ChIP-exo) followed by high throughput sequencing.

Chromatin immunoprecipitation (ChIP) is an indispensable tool in the fields of epigenetics and gene regulation that isolates specific protein-DNA ...

Production of Near-Infrared Sensitive, Core-Shell Vaccine Delivery Platform

Vaccine delivery strategies that can limit the exposure of cargo to organic solvent while enabling novel release profiles are crucial for improving immunization coverage worldwide. Here, a novel injectable, ultraviolet- curable and delayed burst release- enabling vaccine delivery platform called polybubbles is introduced. Cargo was injected into polyester-based polybubbles that were formed in 10% carboxymethycellulose -based aqueous solution. This paper includes protocols to maintain spherical shape of the polybubbles and optimize cargo placement and retention to maximize the amount of cargo within the polybubbles. To ensure safety, chlorinated solvent content within the polybubbles were analyzed using neutron activation analysis. Release studies were conducted with small molecules as cargo within the polybubble to confirm delayed burst release. To further show the potential for on-demand delivery of the cargo, gold nanorods were mixed within the polymer shell to enable near-infrared laser activation.

This article describes the protocols used to produce a novel vaccine delivery platform, &#34;polybubbles,&#34; to enable delayed burst release. Polyesters including poly(lactic-co-glycolic acid) and polycaprolactone were used to form the polybubbles and small molecules and antigen were used as cargo.

Vaccine delivery strategies that can limit the exposure of cargo to organic solvent while enabling novel release profiles are crucial for improving ...

Exploring Adipose Tissue Structure by Methylsalicylate Clearing and 3D Imaging

Obesity is a major worldwide public health issue that increases the risk to develop cardiovascular diseases, type-2 diabetes, and liver diseases. Obesity is characterized by an increase in adipose tissue (AT) mass due to adipocyte hyperplasia and/or hypertrophia, leading to profound remodeling of its three-dimensional structure. Indeed, the maximal capacity of AT to expand during obesity is pivotal to the development of obesity-associated pathologies. This AT expansion is an important homeostatic mechanism to enable adaptation to an excess of energy intake and to avoid deleterious lipid spillover to other metabolic organs, such as muscle and liver. Therefore, understanding the structural remodeling that leads to the failure of AT expansion is a fundamental question with high clinical applicability. In this article, we describe a simple and fast clearing method that is routinely used in our laboratory to explore the morphology of mouse and human white adipose tissue by fluorescent imaging. This optimized AT clearing method is easily performed in any standard laboratory equipped with a chemical hood, a temperature-controlled orbital shaker and a fluorescent microscope. Moreover, the chemical compounds used are readily available. Importantly, this method allows one to resolve the 3D AT structure by staining various markers to specifically visualize the adipocytes, the neuronal and vascular networks, and the innate and adaptive immune cells distribution.

Here, we describe a simple, inexpensive and fast clearing method to resolve the 3D structure of both mouse and human white adipose tissue using a combination of markers to visualize vasculature, nuclei, immune cells, neurons, and lipid-droplet coat proteins by fluorescent imaging.

Obesity is a major worldwide public health issue that increases the risk to develop cardiovascular diseases, type-2 diabetes, and liver diseases. Obesity ...

Dissecting Mechanoenzymatic Properties of Processive Myosins with Ultrafast Force-Clamp Spectroscopy

Ultrafast force-clamp spectroscopy (UFFCS) is a single molecule technique based on laser tweezers that allows the investigation of the chemomechanics of both conventional and unconventional myosins under load with unprecedented time resolution. In particular, the possibility to probe myosin motors under constant force right after the actin-myosin bond formation, together with the high rate of the force feedback (200 kHz), has shown UFFCS to be a valuable tool to study the load dependence of fast dynamics such as the myosin working stroke. Moreover, UFFCS enables the study of how processive and non-processive myosin-actin interactions are influenced by the intensity and direction of the applied force.
By following this protocol, it will be possible to perform ultrafast force-clamp experiments on processive myosin-5 motors and on a variety of unconventional myosins. By some adjustments, the protocol could also be easily extended to the study of other classes of processive motors such as kinesins and dyneins. The protocol includes all the necessary steps, from the setup of the experimental apparatus to sample preparation, calibration procedures, data acquisition and analysis.

Presented here is a comprehensive protocol to perform ultrafast force-clamp experiments on processive myosin-5 motors, which could be easily extended to the study of other classes of processive motors. The protocol details all the necessary steps, from the setup of the experimental apparatus to sample preparation, data acquisition and analysis.

Ultrafast force-clamp spectroscopy (UFFCS) is a single molecule technique based on laser tweezers that allows the investigation of the chemomechanics of ...