rudyvdbrink/CitationDatabase huggingface dataset:
Neurophysiological indices of the transfer of cognitive training gains to untrained tasks.
Neurobiology of learning and memory, 2020

Targeted training of working memory (WM) may improve performance and modulate brain function in untrained cognitive modalities. Demanding cognitive training protocols that do not target WM may also improve performance on untrained cognitive tests, but the delineation between transfer effects that are unique to WM training and effects that are shared among different cognitive training modalities has not been well-established. To address this, we examined the effects of twenty sessions of either WM training (visual n-back task with letter stimuli) or selective attention training (visual search task with letter array stimuli) on brain function during untrained WM and cognitive control tasks. Event-related potentials (ERPs) were obtained at baseline (pretest) and after the training period (posttest) for two untrained tasks - a Spatial 3-back task measuring spatial WM, and a Go/NoGo Flanker task measuring cognitive control. The n-back training group had more pronounced pretest-to-posttest performance improvements on the Spatial 3-back task compared to the search training group. N-back training was also associated with pretest-to-posttest enhancement of N1 amplitude and reduced N2 latency on trials of the task in which where there was a stimulus match, as well as enhancement of a late positive potential (550-750 msec post-stimulus) for all trials of the task. These ERP effects suggest that n-back training resulted in enhancement of attention to spatial locations, earlier onset of conflict monitoring processes, and changes in the engagement of neural activity during the retention interval, respectively. Both groups had faster reaction time on Go trials of the Go/NoGo Flanker task at posttest compared to pretest. Relatively subtle training-related effects were observed for N2 amplitude on this task, in line with the notion that training (particularly n-back training) was associated with improved conflict monitoring. Further, search training resulted in earlier onset of P2 and P3 latency at posttest compared to pretest. Taken together, the ERP findings for both tasks identify specific cognitive processes that are associated with transfer to untrained tasks after distinct forms of cognitive training.
Astroglia in medullary dorsal horn (trigeminal spinal subnucleus caudalis) are involved in trigeminal neuropathic pain mechanisms.
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2009

The aim of this study was to investigate whether astroglia in the medullary dorsal horn (trigeminal spinal subnucleus caudalis; Vc) may be involved in orofacial neuropathic pain following trigeminal nerve injury. The effects of intrathecal administration of the astroglial aconitase inhibitor sodium fluoroacetate (FA) were tested on Vc astroglial hyperactivity [as revealed by glial fibrillary acid protein (GFAP) labeling], nocifensive behavior, Vc extracellular signal-regulated kinase phosphorylation (pERK), and Vc neuronal activity in inferior alveolar nerve-transected (IANX) rats. Compared with sham-control rats, a significant increase occurred in GFAP-positive cells in ipsilateral Vc at postoperative day 7 in IANX rats, which was prevented following FA administration. FA significantly increased the reduced head withdrawal latency to high-intensity heat stimulation of the maxillary whisker pad skin in IANX rats, although it did not significantly affect the reduced escape threshold to low-intensity mechanical stimulation of the whisker skin in IANX rats. FA also significantly reduced the increased number of pERK-like immunoreactive cells in Vc and the enhanced Vc nociceptive neuronal responses following high-intensity skin stimulation that were documented in IANX rats, and glutamine administration restored the enhanced responses. These various findings provide the first documentation that astroglia is involved in the enhanced nociceptive responses of functionally identified Vc nociceptive neurons and in the associated orofacial hyperalgesia following trigeminal nerve injury.
Physical chitosan microhydrogels as scaffolds for spinal cord injury restoration and axon regeneration.
Biomaterials, 2017

Recovery from traumatic spinal cord injury (SCI) usually fails due to a cascade of cellular and molecular events that compromise neural tissue reconstitution by giving rise to glial scarring and cavity formation. We designed a scaffold material for SCI treatment containing only chitosan and water as fragmented physical hydrogel suspension (Chitosan-FPHS), with defined degree of acetylation (DA), polymer concentration, and mean fragment size. Implantation of Chitosan-FPHS alone into rat spinal cord immediately after a bilateral dorsal hemisection promoted reconstitution of spinal tissue and vasculature, and diminished fibrous glial scarring: with astrocyte processes primarily oriented towards the lesion, the border between lesion site and intact tissue became permissive for regrowth of numerous axons into, and for some even beyond the lesion site. Growing axons were myelinated or ensheathed by endogenous Schwann cells that migrated into the lesion site and whose survival was prolonged. Interestingly, Chitosan-FPHS also modulated the inflammatory response, and we suggest that this might contribute to tissue repair. Finally, this structural remodeling was associated with significant, long-lasting gain in locomotor function recovery. Because it effectively induces neural tissue repair, Chitosan-FPHS biomaterial may be a promising new approach to treat SCI, and a suitable substrate to combine with other strategies.
Autoimmune epilepsy in children: case series and proposed guidelines for identification.
Epilepsia, 2013

Antibodies against neuronal surface proteins are increasingly recognized in autoimmune central nervous system (CNS) disorders in which seizures are the main or an important feature. The disorders include antibody-associated limbic encephalitis and N-methyl-D-aspartate receptor (NMDAR) encephalitis; however, seizures of autoimmune etiology may exist beyond the spectrum of these recognized syndromes. Because these seizures are potentially treatable with immune therapy, guidelines are needed to help in their early recognition.
Inhibitory surrounds of motion mechanisms revealed by continuous tracking.
Journal of vision, 2018

Continuous psychophysics is a newly developed technique that allows rapid estimation of visual thresholds by asking subjects to track a moving object, then deriving the integration window underlying tracking behavior (Bonnen, Burge, Yates, Pillow, & Cormack, 2015). Leveraging the continuous flow of stimuli and responses, continuous psychophysics allows for estimation of psychophysical thresholds in as little as 1 min. To date this technique has been applied only to tracking visual objects, where it has been used to measure localization thresholds. Here we adapt the technique to visual motion discrimination, by displaying a drifting grating that changes direction on a binary random walk and asking participants to continuously report drift direction by alternate key press. This technique replicates and confirms well-known findings of the motion-perception system. It also proves particularly valuable in demonstrating induced motion, reinforcing evidence for the existence of antagonistic surround fields. At low contrasts, the surround summates with the center, rather than opposing it, again consistent with existing evidence on classical techniques. The user-friendliness and efficiency of the method may lend it to clinical and developmental work.
Changes in behaviors of male C57BL/6J mice across adult life span and effects of dietary restriction.
Age (Dordrecht, Netherlands), 2012

Behavioral analysis is a high-end read-out of aging impact on an organism, and here, we have analyzed behaviors in 4-, 22-, and 28-month-old male C57BL/6J with a broad range of tests. For comparison, a group of 28-month-old males maintained on dietary restriction (DR) was included. The most conspicuous alteration was the decline in exploration activity with advancing age. Aging also affected other behaviors such as motor skill acquisition and grip strength, in contrast to latency to thermal stimuli and visual placement which were unchanged. Object recognition tests revealed intact working memory at 28 months while memory recollection was impaired already at 22 months. Comparison with female C57BL/6J (Fahlström et al., Neurobiol Aging 32:1868-1880, 2011) revealed that alterations in aged males and females are similar and that several of the behavioral indices correlate with age in both sexes. Moreover, we examined if behavioral indices in 22-month-old males could predict remaining life span as suggested in the study by Ingram and Reynolds (Exp Aging Res 12(3):155-162, 1986) and found that exploratory activity and motor skills accounted for up to 65% of the variance. Consistent with that a high level of exploratory activity and preserved motor capacity indicated a long post-test survival, 28-month-old males maintained on DR were more successful in such tests than ad libitum fed age-matched males. In summary, aged C57BL/6J males are marked by a reduced exploratory activity, an alteration that DR impedes. In light of recently published data, we discuss if a diminishing drive to explore may associate with aging-related impairment of central aminergic pathways.
Regional Distribution of CNS Antigens Differentially Determines T-Cell Mediated Neuroinflammation in a CX3CR1-Dependent Manner.
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2018

T cells continuously sample CNS-derived antigens in the periphery, yet it is unknown how they sample and respond to CNS antigens derived from distinct brain areas. We expressed ovalbumin (OVA) neoepitopes in regionally distinct CNS areas (Cnp-OVA and Nes-OVA mice) to test peripheral antigen sampling by OVA-specific T cells under homeostatic and neuroinflammatory conditions. We show that antigen sampling in the periphery is independent of regional origin of CNS antigens in both male and female mice. However, experimental autoimmune encephalomyelitis (EAE) is differentially influenced in Cnp-OVA and Nes-OVA female mice. Although there is the same frequency of CD45
Auditory cortical neurons convey maximal stimulus-specific information at their best frequency.
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2010

Sensory neurons are often thought to encode information about their preferred stimuli. It has also been proposed that neurons convey the most information about stimuli in the flanks of their tuning curves, where firing rate changes most steeply. Here we demonstrate that the responses of rat auditory cortical neurons convey maximal stimulus-specific information about sound frequency at their best frequency, rather than in the flanks of their tuning curves. Theoretical work has shown that stimulus-specific information shifts from tuning curve slope to peak as neuronal variability increases. These results therefore suggest that with respect to the most informative regions of the tuning curve, auditory cortical neurons operate in a regime of high variability.
Extracellular glucose-dependent IPSC enhancement by leptin in fast-spiking to pyramidal neuron connections via JAK2-PI3K pathway in the rat insular cortex.
Neuropharmacology, 2019

Leptin is produced in the adipocytes and plays a pivotal role in regulation of energy balance by controlling appetite and metabolism. Leptin receptors are widely distributed in the brain, especially in the hypothalamus, hippocampus, and neocortex. The insular cortex (IC) processes gustatory and visceral information, which functionally correlate to feeding behavior. However, it is still an open issue whether and how leptin modulates IC neural activities. Our paired whole-cell patch-clamp recordings using IC slice preparations demonstrated that unitary inhibitory postsynaptic currents (uIPSCs) but not uEPSCs were potentiated by leptin in the connections between pyramidal (PNs) and fast-spiking neurons (FSNs). The leptin-induced increase in uIPSC amplitude was accompanied by a decrease in paired-pulse ratio. Under application of inhibitors of JAK2-PI3K but not MAPK pathway, leptin did not change uIPSC amplitude. Variance-mean analysis revealed that leptin increased the release probability but not the quantal size and the number of release site. These electrophysiological findings suggest that the leptin-induced uIPSC increase is mediated by activation of JAK2-PI3K pathway in presynaptic FSNs. An in vivo optical imaging revealed that leptin application decreased excitatory propagation in IC induced by electrical stimulation of IC. These leptin-induced effects were not observed under the low energy states: low glucose concentration (2.5 mM) in vitro and one-day-fasting condition in vivo. However, leptin enhanced uIPSCs under application of low glucose with an AMPK inhibitor. These results suggest that leptin suppresses IC excitation by facilitating GABA release in FSN→PN connections, which may not occur under a hunger state.
Validation of a new 96-well plate spectrophotometric method for the quantification of compound 48/80 associated with particles.
AAPS PharmSciTech, 2013

A new, simple, inexpensive, and rapid 96-well plate UV spectrophotometric method was developed and validated for the quantification of compound 48/80 (C48/80) associated with particles. C48/80 was quantified at 570 nm after reaction with acetaldehyde and sodium nitroprusside in an alkaline solution (pH 9.6). The method was validated according to the recommendations of the ICH Guidelines for specificity, linearity, range, accuracy, precision, and detection and quantification limits (DL and QL). All the validation parameters were assessed in three different solvents, i.e., deionized water, blank matrix of chitosan nanoparticles, and blank matrix of chitosan/alginate nanoparticles. The method was found to be linear in the concentration range of 5 to 160 μg/ml (R(2)>0.9994). Intraday and interday precision was adequate, with relative standard deviation lower than those given by the Horwitz equation. The mean recoveries of C48/80 from spiked samples ranged between 98.1% and 105.9% for calibration curves done with the blank matrices and between 89.3% and 103.3% for calibration curves done with water, respectively. The DL were lower than 1.01 μg/ml and the QL were lower than 3.30 μg/ml. The results showed that the developed method is sensitive, linear, precise, and accurate for its intended use, with the additional advantages of being cost-effective and time-effective, allowing the use of small-volume samples, and the simultaneous analysis of a large number of samples. The proposed method was already successfully applied to evaluate the loading efficacy of C48/80 chitosan-based nanoparticles and can be easily applied during the development of other C48/80-based formulations.
Corticobasal degeneration: advances in clinicopathology and biomarkers.
Current opinion in neurology, 2019

Corticobasal degeneration (CBD) is a rapidly progressive neurodegenerative tauopathy diagnosed postmortem by pathological examination. The clinical presentation of corticobasal syndrome (CBS) is an apraxic, dystonic, and rigid limb with asymmetrical cortical signs and myoclonus. However, less than half of the patients with CBS receive a CBD diagnosis. As tau-lowering therapies have entered clinical trials, improved antemortem diagnosis of CBD is needed. Here, clinicopathological, neuroimaging, and biofluid data in CBS and/or CBD patients are briefly summarized and some knowledge gaps identified.
Anatomically-constrained tractography: improved diffusion MRI streamlines tractography through effective use of anatomical information.
NeuroImage, 2012

Diffusion MRI streamlines tractography suffers from a number of inherent limitations, one of which is the accurate determination of when streamlines should be terminated. Use of an accurate streamlines propagation mask from segmentation of an anatomical image confines the streamlines to the volume of the brain white matter, but does not take full advantage of all of the information available from such an image. We present a modular addition to streamlines tractography, which makes more effective use of the information available from anatomical image segmentation, and the known properties of the neuronal axons being reconstructed, to apply biologically realistic priors to the streamlines generated; we refer to this as "Anatomically-Constrained Tractography". Results indicate that some of the known false positives associated with tractography algorithms are prevented, such that the biological accuracy of the reconstructions should be improved, provided that state-of-the-art streamlines tractography methods are used.
Association between maternal psychological adversity and lung function in South African infants: A birth cohort study.
Pediatric pulmonology, 2020

The association of perinatal psychological adversity (ie, stressors and distress) with infant lung function (ILF) and development is not well studied in Africa and elsewhere. We determined the association between maternal perinatal psychological adversity and ILF in African infants.
Sensory network dysfunction, behavioral impairments, and their reversibility in an Alzheimer's β-amyloidosis mouse model.
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2011

The unique vulnerability of the olfactory system to Alzheimer's disease (AD) provides a quintessential translational tool for understanding mechanisms of synaptic dysfunction and pathological progression in the disease. Using the Tg2576 mouse model of β-amyloidosis, we show that aberrant, hyperactive olfactory network activity begins early in life, before detectable behavioral impairments or comparable hippocampal dysfunction and at a time when amyloid-β (Aβ) deposition is restricted to the olfactory bulb (OB). Hyperactive odor-evoked activity in the piriform cortex (PCX) and increased OB-PCX functional connectivity emerged at a time coinciding with olfactory behavior impairments. This hyperactive activity persisted until later in life when the network converted to a hyporesponsive state. This conversion was Aβ-dependent, because liver-X receptor agonist treatment to promote Aβ degradation rescued the hyporesponsive state and olfactory behavior. These data lend evidence to a novel working model of olfactory dysfunction in AD and, complimentary to other recent works, suggest that disease-relevant network dysfunction is highly dynamic and region specific, yet with lasting effects on cognition and behavior.
Using animal models to improve the design and application of transcranial electrical stimulation in humans.
Current behavioral neuroscience reports, 2018

Transcranial electrical stimulation (tES) is a non-invasive stimulation technique used for modulating brain function in humans. To help tES reach its full therapeutic potential, it is necessary to address a number of critical gaps in our knowledge. Here, we review studies that have taken advantage of animal models to provide invaluable insight about the basic science behind tES.
Plasma antibodies to Abeta40 and Abeta42 in patients with Alzheimer's disease and normal controls.
Brain research, 2008

Antibodies to amyloid beta protein (Abeta) are present naturally or after Abeta vaccine therapy in human plasma. To clarify their clinical role, we examined plasma samples from 113 patients with Alzheimer's disease (AD) and 205 normal controls using the tissue amyloid plaque immunoreactivity (TAPIR) assay. A high positive rate of TAPIR was revealed in AD (45.1%) and age-matched controls (41.2%), however, no significance was observed. No significant difference was observed in the MMS score or disease duration between TAPIR-positive and negative samples. TAPIR-positive plasma reacted with the Abeta40 monomer and dimer, and the Abeta42 monomer weakly, but not with the Abeta42 dimer. TAPIR was even detected in samples from young normal subjects and young Tg2576 transgenic mice. Although the Abeta40 level and Abeta40/42 ratio increased, and Abeta42 was significantly decreased in plasma from AD groups when compared to controls, no significant correlations were revealed between plasma Abeta levels and TAPIR grading. Thus an immune response to Abeta40 and immune tolerance to Abeta42 occurred naturally in humans without a close relationship to the Abeta burden in the brain. Clarification of the mechanism of the immune response to Abeta42 is necessary for realization of an immunotherapy for AD.
Knocking out DJ-1 attenuates astrocytes neuroprotection against 6-hydroxydopamine toxicity.
Journal of molecular neuroscience : MN, 2013

Astrocytes are the most abundant glial cell type in the brain. Impairment in astrocyte functions can critically influence neuronal survival and leads to neurodegeneration. Parkinson's disease (PD) is a common neurodegenerative disorder, characterized by motor dysfunction that results from progressive neuronal loss. Astrocytic dysfunction was demonstrated in human samples and in experimental models of PD. Mutations in DJ-1 (PARK7) leading to loss of functional protein cause familial PD and enhance sensitivity to oxidative insults. Recently, an increase in DJ-1's expression was found in reactive astrocytes in various neurodegenerative disorders. Here we show that lack of DJ-1 attenuates astrocytes' ability to support neuronal cells, thereby leading to accelerated neuronal damage. DJ-1 knockout mice demonstrated increased vulnerability in vivo to 6-hydroxydopamine (6-OHDA) hemiparkinsonian PD model. Astrocytes isolated from DJ-1 knockout mice showed an inferior ability to protect human neuroblastoma cells against 6-OHDA insult both by co-culture and through their conditioned media, as compared to wild-type astrocytes. DJ-1 knockout astrocytes showed blunted ability to increase the expression of cellular protective mechanisms against oxidative stress mediated via Nrf-2 and HO-1 in response to exposure to 6-OHDA. These experiments demonstrated that lack of DJ-1 impairs astrocyte-mediated neuroprotection.
An open-source hardware and software system for acquisition and real-time processing of electrophysiology during high field MRI.
Journal of neuroscience methods, 2008

Simultaneous recording of electrophysiology and functional magnetic resonance imaging (fMRI) is a technique of growing importance in neuroscience. Rapidly evolving clinical and scientific requirements have created a need for hardware and software that can be customized for specific applications. Hardware may require customization to enable a variety of recording types (e.g., electroencephalogram, local field potentials, or multi-unit activity) while meeting the stringent and costly requirements of MRI safety and compatibility. Real-time signal processing tools are an enabling technology for studies of learning, attention, sleep, epilepsy, neurofeedback, and neuropharmacology, yet real-time signal processing tools are difficult to develop. We describe an open-source system for simultaneous electrophysiology and fMRI featuring low-noise (<0.6microV p-p input noise), electromagnetic compatibility for MRI (tested up to 7T), and user-programmable real-time signal processing. The hardware distribution provides the complete specifications required to build an MRI-compatible electrophysiological data acquisition system, including circuit schematics, print circuit board (PCB) layouts, Gerber files for PCB fabrication and robotic assembly, a bill of materials with part numbers, data sheets, and vendor information, and test procedures. The software facilitates rapid implementation of real-time signal processing algorithms. This system has been used in human EEG/fMRI studies at 3 and 7T examining the auditory system, visual system, sleep physiology, and anesthesia, as well as in intracranial electrophysiological studies of the non-human primate visual system during 3T fMRI, and in human hyperbaric physiology studies at depths of up to 300 feet below sea level.