rudyvdbrink/CitationDatabase huggingface dataset:
The potential lethality of caput medusae.
Medicine, science, and the law, 2021

While gastro-oesophageal varices commonly complicate portal hypertension and may be a life-threatening condition, fatal haemorrhaging from cirrhosis-related caput medusae has seldom been described in the scientific literature. This article documents a rare death due to the rupture of a varix in the umbilical area. This case raises a number of points for medico-legal discussion, such as the negative consequences of an erroneous cause of death in evaluating medical malpractice cases and the importance of a thorough external examination of the body in order to ensure this type of vascular lesion is not overlooked.
Striatal Dopamine and Reward Prediction Error Signaling in Unmedicated Schizophrenia Patients.
Schizophrenia bulletin, 2020

Increased striatal dopamine synthesis capacity has consistently been reported in patients with schizophrenia. However, the mechanism translating this into behavior and symptoms remains unclear. It has been proposed that heightened striatal dopamine may blunt dopaminergic reward prediction error signaling during reinforcement learning. In this study, we investigated striatal dopamine synthesis capacity, reward prediction errors, and their association in unmedicated schizophrenia patients (n = 19) and healthy controls (n = 23). They took part in FDOPA-PET and underwent functional magnetic resonance imaging (fMRI) scanning, where they performed a reversal-learning paradigm. The groups were compared regarding dopamine synthesis capacity (Kicer), fMRI neural prediction error signals, and the correlation of both. Patients did not differ from controls with respect to striatal Kicer. Taking into account, comorbid alcohol abuse revealed that patients without such abuse showed elevated Kicer in the associative striatum, while those with abuse did not differ from controls. Comparing all patients to controls, patients performed worse during reversal learning and displayed reduced prediction error signaling in the ventral striatum. In controls, Kicer in the limbic striatum correlated with higher reward prediction error signaling, while there was no significant association in patients. Kicer in the associative striatum correlated with higher positive symptoms and blunted reward prediction error signaling was associated with negative symptoms. Our results suggest a dissociation between striatal subregions and symptom domains, with elevated dopamine synthesis capacity in the associative striatum contributing to positive symptoms while blunted prediction error signaling in the ventral striatum related to negative symptoms.
Pattern separation beyond the hippocampus: A high-resolution whole-brain investigation of mnemonic discrimination in healthy adults.
Hippocampus, 2021

Episodic memory depends on the computational process of pattern separation in order to establish distinct memory representations of similar episodes. Studies of pattern separation in humans rely on mnemonic discrimination tasks, which have been shown to tax hippocampal-dependent pattern separation. Although previous neuroimaging research has focused on hippocampal processing, little is known about how other brain regions, known to be involved in recognition memory performance, are involved in mnemonic discrimination tasks. Conversely, neuroimaging studies of pattern separation with whole-brain coverage lack spatial resolution to localize activation to hippocampal subfields. In this study, 48 healthy young adult participants underwent whole-brain high-resolution functional MRI (fMRI) scanning while completing a mnemonic discrimination task. A priori region-of-interest analyses revealed activation patterns consistent with pattern separation in distinct hippocampal subregions, particularly in the subiculum. Connectivity analyses revealed a network of cortical regions consistent with the memory retrieval network where fMRI activation was correlated with hippocampal activation. An exploratory whole-brain analysis revealed widespread activation differentially associated with performance of the mnemonic discrimination task. Taken together, these results suggest that a network of brain regions contribute to mnemonic discrimination performance, with the hippocampus and parahippocampal cortex as a hub in the network displaying clear signals consistent with pattern separation and regions such as the dorsal medial prefrontal cortex particularly important for successful lure discrimination.
Changes in the neural correlates of self-blame following mindfulness-based cognitive therapy in remitted depressed participants.
Psychiatry research. Neuroimaging, 2020

Mindfulness-Based-Cognitive-Therapy (MBCT) reduces vulnerability for relapse into depression by helping individuals to counter tendencies to engage in maladaptive repetitive patterns of thinking and respond more compassionately to negative self-judgment. However, little is known about the neural correlates underlying these effects. To elucidate these correlates, we investigated fMRI brain activation during a task eliciting feelings of blaming oneself or others. Sixteen participants in remission from major depressive disorder (MDD) completed fMRI assessments before and after MBCT, alongside self-reported levels of self-compassion, mindfulness, and depression symptoms. Analyses of self-blame versus other-blame contrasts showed a reduction in activation in the bilateral dorsal anterior cingulate/medial superior frontal gyrus after MBCT compared to baseline. Further, exploratory analyses showed that increases in self-kindness after MBCT correlated with reduced activation in the posterior cingulate cortex (PCC)/precuneus in self-blame versus rest contrasts. These findings suggest that MBCT is associated with a reduction in activations in cortical midline regions to self-blame which may be mediated by increasing self-kindness. However, this is a small, uncontrolled study with 16 participants and therefore our results will need confirmation in a controlled study.
An Interview with Cesare Montecucco.
Toxins, 2018

Cesare Montecucco is a member of the board of various leading scientific journals. His research focus is on the regeneration of the peripheral nervous system and on the mechanisms of action of toxins and related diseases, including tetanus, botulism, anthrax and Helicobacter pylori-associated diseases. In this interview, we talked to Cesare Montecucco about his career, learning and culture.
Right inferior frontal gyrus implements motor inhibitory control via beta-band oscillations in humans.
eLife, 2021

Motor inhibitory control implemented as response inhibition is an essential cognitive function required to dynamically adapt to rapidly changing environments. Despite over a decade of research on the neural mechanisms of response inhibition, it remains unclear, how exactly response inhibition is initiated and implemented. Using a multimodal MEG/fMRI approach in 59 subjects, our results reliably reveal that response inhibition is initiated by the right inferior frontal gyrus (rIFG) as a form of attention-independent top-down control that involves the modulation of beta-band activity. Furthermore, stopping performance was predicted by beta-band power, and beta-band connectivity was directed from rIFG to pre-supplementary motor area (pre-SMA), indicating rIFG's dominance over pre-SMA. Thus, these results strongly support the hypothesis that rIFG initiates stopping, implemented by beta-band oscillations with potential to open up new ways of spatially localized oscillation-based interventions.
Effects of intentional movement preparation on response times to symbolic and imitative cues.
Experimental brain research, 2017

Speeded responses to an external cue are slower when the cue interrupts preparation to perform the same or a similar action in a self-paced manner. To explore the mechanism underlying this 'cost of intention', we examined whether the size of the cost is influenced by the nature of the external cue. Specifically, we assessed whether the cost of intention is different for movements made in response to an imitative cue (an on-screen hand movement) compared to those made in response to a symbolic cue. Consistent with previous reports, externally cued responses were significantly slower on trials where participants were preparing to perform an internally driven movement later in the trial. Also as predicted, simple response times to the imitative cue were faster than those made to the symbolic cue. Critically, the cost of intention was similar for each cue type, suggesting that preparing an intentional action influenced responses cued by the symbolic and imitative cues to a similar degree. These findings suggest that the nature of the external cue does not influence the response time delay associated with concurrent intentional preparation. Together with previous findings, the results of the current study shed further light on the potential mechanisms underlying the cost of intention.
Factors associated with hypertension among stroke-free indigenous Africans: Findings from the SIREN study.
Journal of clinical hypertension (Greenwich, Conn.), 2021

Hypertension is one of the most important risk factors for stroke and cardiovascular diseases (CVD) globally. Understanding risk factors for hypertension among individuals with matching characteristics with stroke patients may inform primordial/primary prevention of hypertension and stroke among them. This study identified the risk factors for hypertension among community-dwelling stroke-free population in Ghana and Nigeria. Data for 4267 community-dwelling stroke-free controls subjects in the Stroke Investigative Research and Education Network (SIREN) study in Nigeria and Ghana were used. Participants were comprehensively assessed for sociodemographic, lifestyle and metabolic factors using standard methods. Hypertension was defined as a previous diagnosis by a health professional or use of an anti-hypertensive drug or mean systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg. Logistic regression analysis was used to estimate adjusted odds ratios (aOR) of hypertension and their 95% confidence intervals (CI) at p < .05. Overall, 56.7% of the participants were hypertensive with a higher proportion among respondents aged ≥60 years (53.0%). Factors including physical inactivity (aOR: 9.09; 95% CI: 4.03 to 20.53, p < .0001), diabetes (aOR: 2.70; CI: 1.91 to 3.82, p < .0001), being ≥60 years (aOR: 2.22; 95% CI: 1.78 to 2.77, p < .0001), and family history of CVD (aOR 2.02; CI: 1.59 to 2.56, p < .0001) were associated with increased aOR of hypertension. Lifestyle factors were associated with hypertension in the current population of community-dwelling stroke-free controls in west Africa. Community-oriented interventions to address sedentary lifestyles may benefit this population and reduce/prevent hypertension and stroke among them.
Rapid Eye Movement Sleep Sawtooth Waves Are Associated with Widespread Cortical Activations.
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2020

Sawtooth waves (STW) are bursts of frontocentral slow oscillations recorded in the scalp electroencephalogram (EEG) during rapid eye movement (REM) sleep. Little is known about their cortical generators and functional significance. Stereo-EEG performed for presurgical epilepsy evaluation offers the unique possibility to study neurophysiology
Cuttlefish use stereopsis to strike at prey.
Science advances, 2020

The camera-type eyes of vertebrates and cephalopods exhibit remarkable convergence, but it is currently unknown whether the mechanisms for visual information processing in these brains, which exhibit wildly disparate architecture, are also shared. To investigate stereopsis in a cephalopod species, we affixed "anaglyph" glasses to cuttlefish and used a three-dimensional perception paradigm. We show that (i) cuttlefish have also evolved stereopsis (i.e., the ability to extract depth information from the disparity between left and right visual fields); (ii) when stereopsis information is intact, the time and distance covered before striking at a target are shorter; (iii) stereopsis in cuttlefish works differently to vertebrates, as cuttlefish can extract stereopsis cues from anticorrelated stimuli. These findings demonstrate that although there is convergent evolution in depth computation, cuttlefish stereopsis is likely afforded by a different algorithm than in humans, and not just a different implementation.
Inhibition of neutral sphingomyelinase 2 promotes remyelination.
Science advances, 2020

Myelination requires a highly organized synthesis of multiple lipid species that regulate myelin curvature and compaction. For reasons that are not understood, central nervous system remyelinated axons often have thin myelin sheaths with a disorganized structure susceptible to secondary demyelination. We found that expression of the sphingomyelin hydrolase neutral sphingomyelinase 2 (nSMase2) during the differentiation of oligodendrocyte progenitor cells (OPCs) to myelinating oligodendrocytes changes their response to inflammatory cytokines. OPCs do not express nSMase2 and exhibit a protective/regenerative response to tumor necrosis factor-α and interleukin-1β. Oligodendrocytes express nSMase2 and exhibit a stress response to cytokine challenge that includes an overproduction of ceramide, a sphingolipid that forms negative curvatures in membranes. Pharmacological inhibition or genetic deletion of nSMase2 in myelinating oligodendrocytes normalized the ceramide content of remyelinated fibers and increased thickness and compaction. These results suggest that inhibition of nSMase2 could improve the quality of myelin and stabilize structure.
The near-infrared autofluorescence fingerprint of the brain.
Journal of biophotonics, 2020

The brain is a vital organ involved in most of the central nervous system disorders. Their diagnosis and treatment require fast, cost-effective, high-resolution and high-sensitivity imaging. The combination of a new generation of luminescent nanoparticles and imaging systems working in the second biological window (near-infrared II [NIR-II]) is emerging as a reliable alternative. For NIR-II imaging to become a robust technique at the preclinical level, full knowledge of the NIR-II brain autofluorescence, responsible for the loss of image resolution and contrast, is required. This work demonstrates that the brain shows a peculiar infrared autofluorescence spectrum that can be correlated with specific molecular components. The existence of particular structures within the brain with well-defined NIR autofluorescence fingerprints is also evidenced, opening the door to in vivo anatomical imaging. Finally, we propose a rational selection of NIR luminescent probes suitable for low-noise brain imaging based on their spectral overlap with brain autofluorescence.
Mediating Role of Resilience in the Relationships Between Fear of Happiness and Affect Balance, Satisfaction With Life, and Flourishing.
Europe's journal of psychology, 2019

The present study was a first attempt to examine the mediating role of resilience in the relationships between fear of happiness and affect balance, satisfaction with life, and flourishing. Participants consisted of 256 Turkish adults (174 males and 82 females) and aged between 18 and 62 years (M = 36.97, SD = 9.02). Participants completed measures assessing fear of happiness, affect balance, satisfaction with life, and flourishing. The results showed that fear of happiness was negatively correlated with resilience, affect balance, satisfaction with life, and flourishing, while resilience was positively correlated with affect balance, satisfaction with life, and flourishing. The results of mediation analysis showed that (a) resilience fully mediated the effect of fear of happiness upon flourishing, and satisfaction with life, (b) partially mediated the effect of fear of happiness upon affect balance. These findings suggest that resilience helps to explain the associations between fear of happiness and affect balance, satisfaction with life, and flourishing. This study elucidates the potential mechanism behind the association between fear of happiness and indicators of well-being.
Learning of distant state predictions by the orbitofrontal cortex in humans.
Nature communications, 2019

Representations of our future environment are essential for planning and decision making. Previous research in humans has demonstrated that the hippocampus is a critical region for forming and retrieving associations, while the medial orbitofrontal cortex (OFC) is an important region for representing information about recent states. However, it is not clear how the brain acquires predictive representations during goal-directed learning. Here, we show using fMRI that while participants learned to find rewards in multiple different Y-maze environments, hippocampal activity was highest during initial exposure and then decayed across the remaining repetitions of each maze, consistent with a role in rapid encoding. Importantly, multivariate patterns in the OFC-VPFC came to represent predictive information about upcoming states approximately 30 s in the future. Our findings provide a mechanism by which the brain can build models of the world that span long-timescales to make predictions.
Factors associated with readiness to quit smoking among young adults enrolled in a Facebook-based tobacco and alcohol intervention study.
Addictive behaviors, 2020

Young adults who smoke cigarettes often report heavy episodic drinking (HED) and co-use of other psychoactive substances which may complicate efforts to quit cigarette smoking. The current study examined factors associated with readiness to quit cigarette smoking among young adults who smoke and engage in HED.
Variants in the SK2 channel gene (KCNN2) lead to dominant neurodevelopmental movement disorders.
Brain : a journal of neurology, 2020

KCNN2 encodes the small conductance calcium-activated potassium channel 2 (SK2). Rodent models with spontaneous Kcnn2 mutations show abnormal gait and locomotor activity, tremor and memory deficits, but human disorders related to KCNN2 variants are largely unknown. Using exome sequencing, we identified a de novo KCNN2 frameshift deletion in a patient with learning disabilities, cerebellar ataxia and white matter abnormalities on brain MRI. This discovery prompted us to collect data from nine additional patients with de novo KCNN2 variants (one nonsense, one splice site, six missense variants and one in-frame deletion) and one family with a missense variant inherited from the affected mother. We investigated the functional impact of six selected variants on SK2 channel function using the patch-clamp technique. All variants tested but one, which was reclassified to uncertain significance, led to a loss-of-function of SK2 channels. Patients with KCNN2 variants had motor and language developmental delay, intellectual disability often associated with early-onset movement disorders comprising cerebellar ataxia and/or extrapyramidal symptoms. Altogether, our findings provide evidence that heterozygous variants, likely causing a haploinsufficiency of the KCNN2 gene, lead to novel autosomal dominant neurodevelopmental movement disorders mirroring phenotypes previously described in rodents.
The astrocyte network in the ventral nerve cord neuropil of the Drosophila third-instar larva.
The Journal of comparative neurology, 2020

Understanding neuronal function at the local and circuit level requires understanding astrocyte function. We have provided a detailed analysis of astrocyte morphology and territory in the Drosophila third-instar ventral nerve cord where there already exists considerable understanding of the neuronal network. Astrocyte shape varies more than previously reported; many have bilaterally symmetrical partners, many have a high percentage of their arborization in adjacent segments, and many have branches that follow structural features. Taken together, our data are consistent with, but not fully explained by, a model of a developmental growth process dominated by competitive or repulsive interactions between astrocytes. Our data suggest that the model should also include cell-autonomous aspects, as well as the use of structural features for growth. Variation in location of arborization territory for identified astrocytes was great enough that a standardized scheme of neuropil division among the six astrocytes that populate each hemi-segment is not possible at the third instar. The arborizations of the astrocytes can extend across neuronal functional domains. The ventral astrocyte in particular, whose territory can extend well into the proprioceptive region of the neuropil, has no obvious branching pattern that correlates with domains of particular sensory modalities, suggesting that the astrocyte would respond to neuronal activity in any of the sensory modalities, perhaps integrating across them. This study sets the stage for future studies that will generate a robust, functionally oriented connectome that includes both partners in neuronal circuits-the neurons and the glial cells, providing the foundation necessary for studies to elucidate neuron-glia interactions in this neuropil.
Dissociating prefrontal circuitry in intelligence and memory: neuropsychological correlates of magnetic resonance and diffusion tensor imaging.
Brain imaging and behavior, 2015

We examined intelligence and memory in 25 healthy participants who had both prior magnetic resonance imaging (MRI) of gray matter volumes of medial orbital frontal cortex (mOFC) and rostral anterior cingulate cortex (rACC), along with diffusion tensor imaging (DTI) of posterior and anterior mOFC-rACC white matter microstructure, as assessed by fractional anisotropy (FA). Results showed distinct relationships between these basic structural brain parameters and higher cognition, highlighted by a highly significant correlation of left rACC gray matter volume with memory, and to a lesser extent, though still statistically significant, correlation of left posterior mOFC-rACC FA with intelligence. Regression analyses showed that left posterior mOFC-rACC connections and left rACC gray matter volume each contributed to intelligence, with left posterior mOFC-rACC FA uniquely accounting for between 20.43 and 24.99% of the variance in intelligence, in comparison to 13.54 to 17.98% uniquely explained by left rACC gray matter volume. For memory, only left rACC gray matter volume explained neuropsychological performance, uniquely accounting for a remarkably high portion of individual variation, ranging from 73.61 to 79.21%. These results pointed to differential contributions of white mater microstructure connections and gray matter volumes to individual differences in intelligence and memory, respectively.
Comparing quality of reporting between preprints and peer-reviewed articles in the biomedical literature.
Research integrity and peer review, 2020

Preprint usage is growing rapidly in the life sciences; however, questions remain on the relative quality of preprints when compared to published articles. An objective dimension of quality that is readily measurable is completeness of reporting, as transparency can improve the reader's ability to independently interpret data and reproduce findings.