Quantification of transient increase of the blood-brain barrier permeability to macromolecules by optimized focused ultrasound combined with microbubbles.

Radioimmunotherapy using a radiolabeled monoclonal antibody that targets tumor cells has been shown to be efficient for the treatment of many malignant cancers, with reduced side effects. However, the blood-brain barrier (BBB) inhibits the transport of intravenous antibodies to tumors in the brain. Recent studies have demonstrated that focused ultrasound (FUS) combined with microbubbles (MBs) is a promising method to transiently disrupt the BBB for the drug delivery to the central nervous system.

Differential shift in spatial bias over time depends on observers׳ initial bias: Observer subtypes, or regression to the mean?

Healthy subjects typically exhibit a subtle bias of visuospatial attention favouring left space that is commonly termed 'pseudoneglect'. This bias is attenuated, or shifted rightwards, with decreasing alertness over time, consistent with theoretical models proposing that pseudoneglect is a result of the right hemisphere׳s dominance in regulating attention. Although this 'time-on-task effect' for spatial bias is observed when averaging across whole samples of healthy participants, Benwell, C.

Illicit buprenorphine use, interest in and access to buprenorphine treatment among syringe exchange participants.

Poor access to buprenorphine maintenance treatment (BMT) may contribute to illicit buprenorphine use. This study investigated illicit buprenorphine use and barriers to BMT among syringe exchange participants. Computer-based interviews conducted at a New York City harm reduction agency determined: prior buprenorphine use; barriers to BMT; and interest in BMT.

The neural processes underlying perceptual decision making in humans: recent progress and future directions.

In the last two decades, animal neurophysiology research has made great strides towards explaining how the brain can enable adaptive action in the face of noisy sensory information. In particular, this work has identified neural signals that perform the role of a 'decision variable' which integrates sensory information in favor of a particular outcome up to an action-triggering threshold, consistent with long-standing predictions from mathematical psychology. This has provoked an intensive search for similar neural processes at work in the human brain.

Reduced discomfort during high-definition transcutaneous stimulation using 6% benzocaine.

Background: High-Definition transcranial Direct Current Stimulation (HD-tDCS) allows for non-invasive neuromodulation using an array of compact (approximately 1 cm(2) contact area) "High-Definition" (HD) electrodes, as compared to conventional tDCS (which uses two large pads that are approximately 35 cm(2)). In a previous transcutaneous study, we developed and validated designs for HD electrodes that reduce discomfort over >20 min session with 2 mA electrode current.

Objective: The purpose of this study was to investigate the use of a chemical pretreatment with 6% benzocaine (topical numbing agent) to further reduce subjective discomfort during transcutaneous stimulation and to allow for better sham controlled studies.

Temporal effects of vascular endothelial growth factor and 3,5-cyclic monophosphate on blood-brain barrier solute permeability in vivo.

To test the hypothesis that vascular endothelial growth factor (VEGF) can transiently increase the blood-brain barrier permeability, P, as for peripheral microvessels and that the elevation of 3,5-cyclic monophosphate (cAMP) levels can inhibit the VEGF-induced acute hyperpermeability, we employed multiphoton microscopy to quantify the cerebral microvessel permeability P to various-sized solutes under VEGF and cAMP treatments. The cerebral microcirculation was observed through a section of frontoparietal bone thinned with a microgrinder. Fluorescein (MW 376Da), fluorescein isothioyanate-dextran-20k (FITC-Dex-20k), FITC-Dex-70k, or Alexa Fluor 488-IgG in 1% bovine serum albumin mammalian Ringer's solution was injected into the cerebral circulation via the ipsilateral carotid artery with a syringe pump.

Hypocoordinated solids in particulate media.

We propose a "phase diagram" for particulate systems with purely repulsive contact forces, such as granular media and colloids. We characterize two classes of behavior as a function of the input kinetic energy per degree of freedom T_{0} and packing fraction deviation from jamming onset Δϕ=ϕ-ϕ_{J} using simulations of frictionless disks. Isocoordinated solids (ICS) exist above jamming; they possess an average contact number equal to the isostatic value z_{iso}.

Motor cortex electrical stimulation augments sprouting of the corticospinal tract and promotes recovery of motor function.

The corticospinal system-with its direct spinal pathway, the corticospinal tract (CST) - is the primary system for controlling voluntary movement. Our approach to CST repair after injury in mature animals was informed by our finding that activity drives establishment of connections with spinal cord circuits during postnatal development. After incomplete injury in maturity, spared CST circuits sprout, and partially restore lost function.

Deep two-photon microscopic imaging through brain tissue using the second singlet state from fluorescent agent chlorophyll α in spinach leaf.

Two-photon (2P) excitation of the second singlet (S₂) state was studied to achieve deep optical microscopic imaging in brain tissue when both the excitation (800 nm) and emission (685 nm) wavelengths lie in the "tissue optical window" (650 to 950 nm). S₂ state technique was used to investigate chlorophyll α (Chl α) fluorescence inside a spinach leaf under a thick layer of freshly sliced rat brain tissue in combination with 2P microscopic imaging. Strong emission at the peak wavelength of 685 nm under the 2P S₂ state of Chl α enabled the imaging depth up to 450 μm through rat brain tissue.

Executive dysfunction and reward dysregulation: a high-density electrical mapping study in cocaine abusers.

Executive function deficits and reward dysregulation, which mainly manifests as anhedonia, are well documented in drug abusers. We investigated specific aspects of executive function (inhibitory control and cognitive control), as well as anhedonia, in a cohort of current cocaine abusers in order to ascertain to what extent these factors are associated with more severe drug dependence. Participants filled out questionnaires relating to anhedonia and their addiction history.

Averaging of diffusion tensor imaging direction-encoded color maps for localizing substantia nigra.

Diffusion tensor imaging (DTI) is a form of MRI that has been used extensively to map in vivo the white matter architecture of the human brain. It is also used for mapping subcortical nuclei because of its general sensitivity to tissue orientation differences and effects of iron accumulation on the diffusion signal. While DTI provides excellent spatial resolution in individual subjects, a challenge is visualizing consistent patterns of diffusion orientation across subjects.

Mechanosensing at the vascular interface.

Mammals are endowed with a complex set of mechanisms that sense mechanical forces imparted by blood flow to endothelial cells (ECs), smooth muscle cells, and circulating blood cells to elicit biochemical responses through a process referred to as mechanotransduction. These biochemical responses are critical for a host of other responses, including regulation of blood pressure, control of vascular permeability for maintaining adequate perfusion of tissues, and control of leukocyte recruitment during immunosurveillance and inflammation. This review focuses on the role of the endothelial surface proteoglycan/glycoprotein layer-the glycocalyx (GCX)-that lines all blood vessel walls and is an agent in mechanotransduction and the modulation of blood cell interactions with the EC surface.

Discrimination, arrest history, and major depressive disorder in the U.S. Black population.

Everyday discrimination contributes negatively to depressive symptomatology among Blacks in the US and being arrested could add to this depression. Using data from the National Survey on American Life, the present study determined the association between an arrest history and major depressive disorder (MDD), while accounting for discrimination among African Americans, US-born Afro-Caribbeans and first-generation Black immigrants. Findings from logistic regression analyses adjusted for discrimination suggested an arrest history is associated with 12-month MDD (Adjusted OR=1.

Deep optical imaging of tissue using the second and third near-infrared spectral windows.

Light at wavelengths in the near-infrared (NIR) region allows for deep penetration and minimal absorption through high scattering tissue media. NIR light has been conventionally used through the first NIR optical tissue window with wavelengths from 650 to 950 nm. Longer NIR wavelengths had been overlooked due to major water absorption peaks and a lack of NIR-CCD detectors.

EphA4-mediated ipsilateral corticospinal tract misprojections are necessary for bilateral voluntary movements but not bilateral stereotypic locomotion.

In this study, we took advantage of the reported role of EphA4 in determining the contralateral spinal projection of the corticospinal tract (CST) to investigate the effects of ipsilateral misprojections on voluntary movements and stereotypic locomotion. Null EphA4 mutations produce robust ipsilateral CST misprojections, resulting in bilateral corticospinal tracts. We hypothesize that a unilateral voluntary limb movement, not a stereotypic locomotor movement, will become a bilateral movement in EphA4 knock-out mice with a bilateral CST.

Transcranial slow oscillation stimulation during sleep enhances memory consolidation in rats.

Background: The importance of slow-wave sleep (SWS), hallmarked by the occurrence of sleep slow oscillations (SO), for the consolidation of hippocampus-dependent memories has been shown in numerous studies. Previously, the application of transcranial direct current stimulation, oscillating at the frequency of endogenous slow oscillations, during SWS enhanced memory consolidation for a hippocampus dependent task in humans suggesting a causal role of slowly oscillating electric fields for sleep dependent memory consolidation.

Objective: Here, we aimed to replicate and extend these findings to a rodent model.

Throwing out the rules: anticipatory alpha-band oscillatory attention mechanisms during task-set reconfigurations.

We assessed the role of alpha-band oscillatory activity during a task-switching design that required participants to switch between an auditory and a visual task, while task-relevant audiovisual inputs were simultaneously presented. Instructional cues informed participants which task to perform on a given trial and we assessed alpha-band power in the short 1.35-s period intervening between the cue and the task-imperative stimuli, on the premise that attentional biasing mechanisms would be deployed to resolve competition between the auditory and visual inputs.

Molecular dynamics simulations: insight into molecular phenomena at interfaces.

Molecular dynamics simulations, when aptly devised, can enhance our fundamental understanding of a system, set up a platform for testing theoretical predictions, and provide insight and a framework for further experimental studies. This feature article highlights the importance of molecular dynamics simulations in understanding interfacial phenomena using three case studies involving liquid-liquid and solid-liquid interfaces. After briefly reviewing molecular dynamics methods, we discuss velocity slip at a liquid-liquid interface, the coalescence of liquid drops in suspension and in free space, and the behavior of colloidal nanoparticles at a liquid-liquid interface.

Susceptibility to distraction in autism spectrum disorder: probing the integrity of oscillatory alpha-band suppression mechanisms.

When attention is directed to one information stream over another, the brain can be configured in advance to selectively process the relevant stream and suppress potentially distracting inputs. One key mechanism of suppression is through the deployment of anticipatory alpha-band (~10 Hz) oscillatory activity, with greater alpha-band power observed in cortical regions that will ultimately process the distracting stream. Atypical attention has been implicated in autism spectrum disorder (ASD), including greater interference by distracting task-irrelevant inputs.

Tryptophan as the fingerprint for distinguishing aggressiveness among breast cancer cell lines using native fluorescence spectroscopy.

Tryptophan is investigated as the key native marker in cells to determine the level of metastasis competence in breast cell lines using native fluorescence spectroscopy. The ratio of fluorescence intensity at 340 nm to intensity at 460 nm is associated with aggressiveness of the cancer cells. We found that the fluorescence of aggressive breast cancer cell has a much higher contribution from tryptophan compared with that from the normal cells and nonaggressive breast cancer cell.

Postnatal maturation of the red nucleus motor map depends on rubrospinal connections with forelimb motor pools.

The red nucleus (RN) and rubrospinal tract (RST) are important for forelimb motor control. Although the RST is present postnatally in cats, nothing is known about when rubrospinal projections could support motor functions or the relation between the development of the motor functions of the rubrospinal system and the corticospinal system, the other major system for limb control. Our hypothesis is that the RN motor map is present earlier in development than the motor cortex (M1) map, to support early forelimb control.

Impairments in background and event-related alpha-band oscillatory activity in patients with schizophrenia.

Studies show that patients with schizophrenia exhibit impaired responses to sensory stimuli, especially at the early stages of neural processing. In particular, patients' alpha-band (8-14 Hz) event-related desynchronization (ERD) and visual P1 event-related potential (ERP) component tend to be significantly reduced, with P1 ERP deficits greater for visual stimuli biased towards the magnocellular system. In healthy controls, studies show that pre-stimulus alpha (background alpha) plays a pivotal role in sensory processing and behavior, largely by shaping the neural responses to incoming stimuli.