rudyvdbrink/CitationDatabase huggingface dataset:
Cytoskeletal transition at the paranodes: the Achilles' heel of myelinated axons.
Neuron glia biology, 2007

Myelination organizes axons into distinct domains that allow nerve impulses to propagate in a saltatory manner. The edges of the myelin sheath are sealed at the paranodes by axon-glial junctions that have a crucial role in organizing the axonal cytoskeleton. Here we propose a model in which the myelinated axons depend on the axon-glial junctions to stabilize the cytoskeletal transition at the paranodes. Thus paranodal regions are likely to be particularly susceptible to damage induced by demyelinating diseases such as multiple sclerosis.
Dynamic Cerebral Autoregulation Is an Independent Functional Outcome Predictor of Mild Acute Ischemic Stroke.
Stroke, 2018

Background and Purpose- Cerebral autoregulation is impaired in patients with acute ischemic stroke. The purpose of this study was to investigate whether dynamic cerebral autoregulation (dCA) indices constitute an independent functional outcome predictor of acute ischemic stroke. Methods- In this study, 86 patients at days 3 to 7 after acute ischemic stroke and 40 age- and sex-matched controls were enrolled for assessing their dCA indices under spontaneous hemodynamic fluctuations. The dCA indices of patients with favorable outcomes (modified Rankin Scale score ≤1 at 3 months, n=65), patients with unfavorable outcomes (modified Rankin Scale score ≥2 at 3 months, n=21), and controls were compared. Results- The dCA indices, namely the phase shift at very low frequency band (phase_VLF), in the patients with unfavorable outcomes were significantly worse than those in the patients with favorable outcomes. However, the phase_VLF in the patients with favorable outcomes did not differ from those in the controls. Impaired dCA was associated with elevated mean arterial pressure and large infarction volume but was also present in patients with normal mean arterial pressure or small infarction volume. Phase_VLF was a predictor of outcomes in the receiver operating characteristic analysis (area under the curve: 0.722; P<0.001). Multivariate analysis revealed that a phase_VLF value of <61° was independently associated with unfavorable outcomes (odds ratio=4.90; P=0.024). Conclusions- Phase_VLF is an independent functional outcome predictor of acute ischemic stroke.
The Severity of Gambling and Gambling Related Cognitions as Predictors of Emotional Regulation and Coping Strategies in Adolescents.
Journal of gambling studies, 2021

People with gambling disorder (GD) exhibit distorted cognitions and superstitious beliefs more often than the general population. Similarly, difficulties in coping and emotion dysregulation are more prevalent among those with GD, and could determine the onset of GD in particularly vulnerable groups such as adolescents. This study examines the relationship between gambling severity and gambling-related cognitions with coping strategies and emotion regulation. Also, it explores how accurately gambling severity and gambling-related cognitions were able to predict emotion regulation and coping strategies. Two groups were recruited and analyzed: a community sample comprising 250 adolescents and young adults from secondary education schools, and a clinical sample of 31 patients with similar age characteristics seeking treatment for GD. The participants from the clinical sample scored higher on gambling severity, emotion dysregulation, cognitive biases, and maladaptive coping strategies. In the community sample, cognitive biases mediated the relationship between sex and emotion dysregulation and disengagement. People with GD use more often than controls maladaptive emotion regulation strategies to manage negative emotional states. This perspective emphasizes the need to focus on coping with emotions, as opposed to coping with problems, as the best approach to tackle gambling problems.
Assessing the Effect of Training on the Cognition and Brain of Older Adults: Protocol for a Three-Arm Randomized Double-Blind Controlled Trial (ACTOP).
JMIR research protocols, 2020

To prevent age-related cognitive impairment, many intervention programs offer exercises targeting different central cognitive processes. However, the effects of different process-based training programs are rarely compared within equivalent experimental designs.
Detecting synchrony in EEG: A comparative study of functional connectivity measures.
Computers in biology and medicine, 2019

In neuroscience, there is considerable current interest in investigating the connections between different parts of the brain. EEG is one modality for examining brain function, with advantages such as high temporal resolution and low cost. Many measures of connectivity have been proposed, but which is the best measure to use? In this paper, we address part of this question: which measure is best able to detect connections that do exist, in the challenging situation of non-stationary and noisy data from nonlinear systems, like EEG. This requires knowledge of the true relationship between signals, hence we compare 26 measures of functional connectivity on simulated data (unidirectionally coupled Hénon maps, and simulated EEG). To determine whether synchrony is detected, surrogate data were generated and analysed, and a threshold determined from the surrogate ensemble. No measure performed best in all tested situations. The correlation and coherence measures performed best on stationary data with many samples. S-estimator, correntropy, mean-phase coherence (Hilbert), mutual information (kernel), nonlinear interdependence (S) and nonlinear interdependence (N) performed most reliably on non-stationary data with small to medium window sizes. Of these, correlation and S-estimator have execution times that scale slower with the number of channels and the number of samples.
Duloxetine Improves Spinal Cord Stimulation Outcomes for Chronic Pain.
Neuromodulation : journal of the International Neuromodulation Society, 2019

Spinal cord stimulation (SCS) has been shown to be effective in treating chronic pain in patients with varying etiologies. However, the impact of pharmacological treatment on augmenting response to SCS has not been previously studied.
Predicting suicidal behavior among lesbian, gay, bisexual, and transgender youth receiving psychiatric emergency services.
Journal of psychiatric research, 2020

Lesbian, gay, bisexual, and transgender (LGBT) youth are at elevated risk for self-injurious thoughts and behaviors (SITBs). However, few studies have comprehensively examined SITBs and their longitudinal course in LGBT youth at high risk for suicide. The aims of the present study were to characterize histories of SITBs among high-risk LGBT youth and to examine prospective associations with suicidal behavior. Participants were 285 youth (41.8% LGBT) ages 13-25 years receiving psychiatric emergency department (ED) services. Post-discharge suicidal behavior was assessed via 4-month phone interviews and 12 month chart reviews. The sample was 42.1% male, 57.9% female, 2.5% gender minority, 41.8% sexual minority. LGBT participants were more likely to have prior psychiatric ED visits and hospitalizations, more frequent past week suicide ideation, and more severe nonsuicidal self-injury (NSSI). We conducted stratified survival analyses to identify predictors of time to suicidal behavior post discharge. The final model for LGBT youth included past week suicide ideation and past month NSSI episodes. Among non-LGBT youth, the final model included number of lifetime NSSI methods and use of a highly lethal suicide attempt method. Within this sample of youth receiving psychiatric emergency services, LGBT youth were overrepresented and had more severe histories of SITBs. Results suggest the importance of assessing both lifetime and recent factors (i.e., past week and month), particularly for LGBT youth. Future research should replicate these findings in larger samples to explore whether there are unique risk factors that can aid in predicting and preventing suicide among LGBT youth.
Specific alterations in the performance of learning and memory tasks in models of chemoconvulsant-induced status epilepticus.
Epilepsy research, 2014

Cognitive impairment is a common comorbidity in patients with Temporal Lobe Epilepsy (TLE). These impairments, particularly deficits in learning and memory, can be recapitulated in chemoconvulsant models of TLE. Here, we used two relatively low-stress behavioral paradigms, the novel object recognition task (NOR) and a spatial variation, the novel placement recognition task (NPR) to reveal deficits in short and long term memory, in both kainic acid (KA) and pilocarpine (Pilo) treated animals. We found that both KA- and Pilo-induced significant deficits in long term recognition memory but not short term recognition memory. Additionally, KA impaired spatial memory as detected by both NPR and Morris water maze. These deficits were present 1 week after SE. The characterization of memory performance of two chemoconvulsant-models, one of which is considered a surrogate organophosphate, provides an avenue for which targeted cognitive therapeutics can be tested.
Stability of two cluster solutions in pulse coupled networks of neural oscillators.
Journal of computational neuroscience, 2011

Phase response curves (PRCs) have been widely used to study synchronization in neural circuits comprised of pacemaking neurons. They describe how the timing of the next spike in a given spontaneously firing neuron is affected by the phase at which an input from another neuron is received. Here we study two reciprocally coupled clusters of pulse coupled oscillatory neurons. The neurons within each cluster are presumed to be identical and identically pulse coupled, but not necessarily identical to those in the other cluster. We investigate a two cluster solution in which all oscillators are synchronized within each cluster, but in which the two clusters are phase locked at nonzero phase with each other. Intuitively, one might expect this solution to be stable only when synchrony within each isolated cluster is stable, but this is not the case. We prove rigorously the stability of the two cluster solution and show how reciprocal coupling can stabilize synchrony within clusters that cannot synchronize in isolation. These stability results for the two cluster solution suggest a mechanism by which reciprocal coupling between brain regions can induce local synchronization via the network feedback loop.
Slow inactivation of the NaV1.4 sodium channel in mammalian cells is impeded by co-expression of the beta1 subunit.
Pflugers Archiv : European journal of physiology, 2009

In response to sustained depolarization or prolonged bursts of activity in spiking cells, sodium channels enter long-lived non-conducting states from which recovery at hyperpolarized potentials occurs over hundreds of milliseconds to seconds. The molecular basis for this slow inactivation remains unknown, although many functional domains of the channel have been implicated. Expression studies in Xenopus oocytes and mammalian cell lines have suggested a role for the accessory beta1 subunit in slow inactivation, but the effects have been variable. We examined the effects of the beta1 subunit on slow inactivation of skeletal muscle (NaV1.4) sodium channels expressed in HEK cells. Co-expression of the beta1 subunit impeded slow inactivation elicited by a 30-s depolarization, such that the voltage dependence was right shifted (depolarized) and recovery was hastened. Mutational studies showed this effect was dependent upon the extracellular Ig-like domain, but was independent of the intracellular C-terminal tail. Furthermore, the beta1 effect on slow inactivation was shown to be independent of the negative coupling between fast and slow inactivation.
Functional screening of guide RNAs targeting the regulatory and structural HIV-1 viral genome for a cure of AIDS.
AIDS (London, England), 2016

There is an urgent need for the development of HIV-1 genome eradication strategies that lead to a permanent cure for HIV-1/AIDS. We previously reported that four guide RNAs (gRNAs) targeting HIV-1 long terminal repeats (LTR) effectively eradicated the entire HIV-1 genome. In this study, we sought to identify the best gRNAs targeting HIV-1 LTR and viral structural region and optimize gRNA pairing that can efficiently eradicate the HIV-1 genome.
Animal Orientation Affects Brain Biomechanical Responses to Blast-Wave Exposure.
Journal of biomechanical engineering, 2021

In this study, we investigated how animal orientation within a shock tube influences the biomechanical responses of the brain and cerebral vasculature of a rat when exposed to a blast wave. Using three-dimensional finite element (FE) models, we computed the biomechanical responses when the rat was exposed to the same blast-wave overpressure (100 kPa) in a prone (P), vertical (V), or head-only (HO) orientation. We validated our model by comparing the model-predicted and the experimentally measured brain pressures at the lateral ventricle. For all three orientations, the maximum difference between the predicted and measured pressures was 11%. Animal orientation markedly influenced the predicted peak pressure at the anterior position along the midsagittal plane of the brain (P = 187 kPa; V = 119 kPa; and HO = 142 kPa). However, the relative differences in the predicted peak pressure between the orientations decreased at the medial (21%) and posterior (7%) positions. In contrast to the pressure, the peak strain in the prone orientation relative to the other orientations at the anterior, medial, and posterior positions was 40-88% lower. Similarly, at these positions, the cerebral vasculature strain in the prone orientation was lower than the strain in the other orientations. These results show that animal orientation in a shock tube influences the biomechanical responses of the brain and the cerebral vasculature of the rat, strongly suggesting that a direct comparison of changes in brain tissue observed from animals exposed at different orientations can lead to incorrect conclusions.
How to carry out conceptual properties norming studies as parameter estimation studies: Lessons from ecology.
Behavior research methods, 2021

Conceptual properties norming studies (CPNs) ask participants to produce properties that describe concepts. From that data, different metrics may be computed (e.g., semantic richness, similarity measures), which are then used in studying concepts and as a source of carefully controlled stimuli for experimentation. Notwithstanding those metrics' demonstrated usefulness, researchers have customarily overlooked that they are only point estimates of the true unknown population values, and therefore, only rough approximations. Thus, though research based on CPN data may produce reliable results, those results are likely to be general and coarse-grained. In contrast, we suggest viewing CPNs as parameter estimation procedures, where researchers obtain only estimates of the unknown population parameters. Thus, more specific and fine-grained analyses must consider those parameters' variability. To this end, we introduce a probabilistic model from the field of ecology. Its related statistical expressions can be applied to compute estimates of CPNs' parameters and their corresponding variances. Furthermore, those expressions can be used to guide the sampling process. The traditional practice in CPN studies is to use the same number of participants across concepts, intuitively believing that practice will render the computed metrics comparable across concepts and CPNs. In contrast, the current work shows why an equal number of participants per concept is generally not desirable. Using CPN data, we show how to use the equations and discuss how they may allow more reasonable analyses and comparisons of parameter values among different concepts in a CPN, and across different CPNs.
Emotion-attention interactions in fear conditioning: Moderation by executive load, neuroticism, and awareness.
Biological psychology, 2016

Despite increasing evidence suggesting interactive effects of emotion and attention on perceptual processing, it still remains unclear how their interplay influences affective learning, such as fear conditioning. In the present study, a conditioning procedure using threat-related conditioned stimuli (CSs) was implemented while executive load and attentional focus were manipulated. The modulation effects of neuroticism and contingency awareness were also examined. Results showed that fear conditioning depended on the available executive resources even with threat-related CSs. In addition, although individuals with high neuroticism showed an enhanced conditioning effect overall, this facilitation effect still depended on the availability of executive resources. Finally, the impact of attentional focus was most evident among individuals with high neuroticism who were aware of the contingency. Overall, the present study demonstrates interactive effects of emotion and attention in fear conditioning, while illuminating mechanisms of individual differences and clarifying the controversial role of contingency awareness in fear conditioning.
Congenital amusia: a short-term memory deficit for non-verbal, but not verbal sounds.
Brain and cognition, 2009

Congenital amusia refers to a lifelong disorder of music processing and is linked to pitch-processing deficits. The present study investigated congenital amusics' short-term memory for tones, musical timbres and words. Sequences of five events (tones, timbres or words) were presented in pairs and participants had to indicate whether the sequences were the same or different. The performance of congenital amusics confirmed a memory deficit for tone sequences, but showed normal performance for word sequences. For timbre sequences, amusics' memory performance was impaired in comparison to matched controls. Overall timbre performance was found to be correlated with melodic contour processing (as assessed by the Montreal Battery of Evaluation of Amusia). The present findings show that amusics' deficits extend to non-verbal sound material other than pitch, in this case timbre, while not affecting memory for verbal material. This is in line with previous suggestions about the domain-specificity of congenital amusia.
Somatostatin cells regulate sensory response fidelity via subtractive inhibition in olfactory cortex.
Nature neuroscience, 2015

Diverse types of local GABAergic interneurons shape the cortical representation of sensory information. Here we show how somatostatin-expressing interneurons (SOM cells) contribute to odor coding in mouse olfactory cortex. We find that odor-tuned SOM cells regulate principal cells through a purely subtractive operation that is independent of odor identity or intensity. This operation enhances the salience of odor-evoked activity without changing cortical odor tuning. SOM cells inhibit both principal cells and fast-spiking interneurons, indicating that subtractive inhibition reflects the interplay of multiple classes of interneurons.
Assessment of attachment in psychosis: A psychometric cause for concern.
Psychiatry research, 2016

Attachment has recently been proposed as a key developmental construct in psychosis, in particular with respect to interpersonal functioning and social cognition. The current study examined the latent structure of the self-report Psychosis Attachment Measure (PAM) and its relationship to lower-level perceptual and higher-order inferential social cognitive processes. The PAM was administered to 138 psychiatrically stable outpatients with schizophrenia alongside a battery of symptom, social cognitive, and functional measures. PAM responses were analyzed using latent variable measurement models, which did not yield evidence of the coherent two-dimensional structure predicted by previous literature. A unidimensional subscale comprising 6 of the 16 original PAM items possessed the strongest psychometric properties. This subscale was generally uncorrelated with social cognitive measures and showed weak correlations with some symptoms measures and with community functioning. These results suggest that either the PAM may not measure attachment in psychosis or it may measure only attachment anxiety but demonstrate little construct validity in this population. These results tell a cautionary tale regarding making theoretical inferences on the basis of measures without coherent latent structure. Attachment measures with stronger psychometric properties will help clarify putative relationships between attachment and social cognitive processes in psychosis.
Effects of i.c.v. administration of interleukin-1 on sleep and body temperature of interleukin-6-deficient mice.
Neuroscience, 2008

Cytokines in brain contribute to the regulation of physiological processes and complex behavior, including sleep. The cytokines that have been most extensively studied with respect to sleep are interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and IL-6. Administration of these cytokines into laboratory animals, or in some cases into healthy human volunteers, increases the amount of time spent in non-rapid eye movement (NREM) sleep. Although antagonizing the IL-1 or TNF systems reduces the amount of time laboratory animals spend in NREM sleep, interactions among these three cytokine systems as they pertain to the regulation of physiological NREM sleep are not well understood. To further elucidate mechanisms in brain by which IL-1beta, TNFalpha, and/or IL-6 contribute to NREM sleep regulation, we injected recombinant murine interleukin-1beta (muIL-1beta) into C57BL/6J mice and into IL-6-deficient mice (IL-6 knockout, KO). IL-6 KO (B6.129S6-Il6(tm1Kopf); n=13) and C57BL/6J mice (n=14) were implanted with telemeters to record the electroencephalogram (EEG) and core body temperature, as well as with indwelling guide cannulae targeted to one of the lateral ventricles. After recovery and habituation, mice were injected intracerebroventricularly just prior to dark onset on different days with either 0.5 microl vehicle (pyrogen-free saline; PFS) or with 0.5 microl PFS containing one of four doses of muIL-1beta (2.5 ng, 5 ng, 10 ng, 50 ng). No mouse received more than two doses of muIL-1beta, and administration of muIL-1beta doses was counter-balanced to eliminate potential order effects. Sleep-wake behavior was determined for 24 h after injections. i.c.v. administration of muIL-1beta increased in NREM sleep of both mouse strains in a dose-related fashion, but the maximal increase was of greater magnitude in C57Bl/6J mice. muIL-1beta induced fever in C57Bl/6J mice but not in IL-6 KO mice. Collectively, these data demonstrate IL-6 is necessary for IL-1 to induce fever, but IL-6 is not necessary for IL-1 to alter NREM sleep.