α-Synuclein in Parkinson's disease: causal or bystander?

Parkinson's disease (PD) comprises a spectrum of disorders with differing subtypes, the vast majority of which share Lewy bodies (LB) as a characteristic pathological hallmark. The process(es) underlying LB generation and its causal trigger molecules are not yet fully understood. α-Synuclein (α-syn) is a major component of LB and SNCA gene missense mutations or duplications/triplications are causal for rare hereditary forms of PD.

New Graph-Theoretical-Multimodal Approach Using Temporal and Structural Correlations Reveals Disruption in the Thalamo-Cortical Network in Patients with Schizophrenia.

Schizophrenia has been understood as a network disease with altered functional and structural connectivity in multiple brain networks compatible to the extremely broad spectrum of psychopathological, cognitive, and behavioral symptoms in this disorder. When building brain networks, functional and structural networks are typically modeled independently: Functional network models are based on temporal correlations among brain regions, whereas structural network models are based on anatomical characteristics. Combining both features may give rise to more realistic and reliable models of brain networks.

Identifying predictors of within-person variance in MRI-based brain volume estimates.

Adequate reliability of measurement is a precondition for investigating individual differences and age-related changes in brain structure. One approach to improve reliability is to identify and control for variables that are predictive of within-person variance. To this end, we applied both classical statistical methods and machine-learning-inspired approaches to structural magnetic resonance imaging (sMRI) data of six participants aged 24-31 years gathered at 40-50 occasions distributed over 6-8 months from the Day2day study.

Influence of nutritional tyrosine on cognition and functional connectivity in healthy old humans.

Tyrosine is precursor for monoamine neurotransmitters such as dopamine (DA), which is one of the key neurotransmitters in the frontostriatal network and of crucial relevance for mental disorders. Recent research reported that high dose tyrosine application resulted in increased brain DA synthesis, which is consistent with the observation of positive associations between daily tyrosine intake and cognitive test performance. In the present study, we investigated the associations between working memory (WM) dependent tasks and self-reported nutritional tyrosine intake within a large group of healthy elderly humans (286 subjects) by additionally including brain functional data.

Impact of Intraoperative Hyperglycemia on Brain Structures and Volumes.

Background And Purpose: In hyperglycemic patients, who succumbed to septic shock, an increased rate of apoptosis of microglial cells and damaged neurons of the hippocampus were found. However, the influence of perioperative glucose levels on hippocampal brain structures has not yet been investigated.

Methods: As part of the ongoing BIOCOG project, a subgroup of N = 65 elderly nondemented patients were analyzed who underwent elective surgery of ≥60 minutes.

Assessing reliability in neuroimaging research through intra-class effect decomposition (ICED).

Magnetic resonance imaging has become an indispensable tool for studying associations of structural and functional properties of the brain with behavior in humans. However, generally recognized standards for assessing and reporting the reliability of these techniques are still lacking. Here, we introduce a new approach for assessing and reporting reliability, termed intra-class effect decomposition (ICED).

Quantifying insightful problem solving: a modified compound remote associates paradigm using lexical priming to parametrically modulate different sources of task difficulty.

Insight problem solving has been conceptualized as a dynamic search through a constrained search space, where a non-obvious solution needs to be found. Multiple sources of task difficulty have been defined that can keep the problem solver from finding the right solution such as an overly large search space or knowledge constraints requiring a change of the problem representation. Up to now, there are very few accounts that focus on different aspects of difficulty within an insight problem-solving context and how they affect task performance as well as the probability of finding a solution that is accompanied by an Aha! experience.

Hippocampal gray matter increases following multimodal psychological treatment for combat-related post-traumatic stress disorder.

Introduction: Smaller hippocampal volumes are one of the most consistent findings in neuroimaging studies of post-traumatic stress disorder (PTSD). However, very few prospective studies have assessed changes in hippocampal gray matter prior to and following therapy for PTSD, and no neuroimaging studies to date have longitudinally assessed military populations.

Methods: A pilot study was conducted, assessing patients with combat-related PTSD with structural MRI.

Extracting orthogonal subject- and condition-specific signatures from fMRI data using whole-brain effective connectivity.

The study of brain communication based on fMRI data is often limited because such measurements are a mixture of session-to-session variability with subject- and condition-related information. Disentangling these contributions is crucial for real-life applications, in particular when only a few recording sessions are available. The present study aims to define a reliable standard for the extraction of multiple signatures from fMRI data, while verifying that they do not mix information about the different modalities (e.

Lateralisation in Parkinson disease.

Asymmetry of dopaminergic neurodegeneration and subsequent lateralisation of motor symptoms are distinctive features of Parkinson's disease compared to other forms of neurodegenerative or symptomatic parkinsonism. Even 200 years after the first description of the disease, the underlying causes for this striking clinicopathological feature are not yet fully understood. There is increasing evidence that lateralisation of disease is due to a complex interplay of hereditary and environmental factors that are reflected not only in the concept of dominant hemispheres and handedness but also in specific susceptibilities of neuronal subpopulations within the substantia nigra.

Does playing violent video games cause aggression? A longitudinal intervention study.

It is a widespread concern that violent video games promote aggression, reduce pro-social behaviour, increase impulsivity and interfere with cognition as well as mood in its players. Previous experimental studies have focussed on short-term effects of violent video gameplay on aggression, yet there are reasons to believe that these effects are mostly the result of priming. In contrast, the present study is the first to investigate the effects of long-term violent video gameplay using a large battery of tests spanning questionnaires, behavioural measures of aggression, sexist attitudes, empathy and interpersonal competencies, impulsivity-related constructs (such as sensation seeking, boredom proneness, risk taking, delay discounting), mental health (depressivity, anxiety) as well as executive control functions, before and after 2 months of gameplay.

Community violence exposure correlates with smaller gray matter volume and lower IQ in urban adolescents.

Adolescents' exposure to community violence is a significant public health issue in urban settings and has been associated with poorer cognitive performance and increased risk for psychiatric illnesses, including PTSD. However, no study to date has investigated the neural correlates of community violence exposure in adolescents. Sixty-five healthy adolescents (age = 14-18 years; 36 females, 29 males) from moderate- to high-crime neighborhoods in Los Angeles reported their violence exposure, parents' education level, and free/reduced school lunch status (socio-economic status, SES), and underwent structural neuroimaging and intelligence testing.

The Myth of Blunted Gamers: No Evidence for Desensitization in Empathy for Pain after a Violent Video Game Intervention in a Longitudinal fMRI Study on Non-Gamers.

Background/aims: It is a common concern in the research field and the community that habitual violent video gaming reduces empathy for pain in its players. However, previous fMRI studies have only compared habitual game players against control participants cross-sectionally. However the observed pattern of results may be due to a priori differences in people who become gamers and who not.

Psychological and neural correlates of embitterment in old age.

Objective: Posttraumatic embitterment disorder (PTED) comprises a stress-related response to a negative life event that violates the belief system of the individual. Characteristic symptoms involve repeated intrusive thoughts, emotional arousal when reminded of the event, and decreases in well-being.

Method: Within the scope of the present study, embitterment was treated as a continuous rather than categorical concept, and we investigated its psychological and brain structural correlates in a sample of healthy older adults.

Food for thought: association between dietary tyrosine and cognitive performance in younger and older adults.

The fact that tyrosine increases dopamine availability that, in turn, may enhance cognitive performance has led to numerous studies on healthy young participants taking tyrosine as a food supplement. As a result of this dietary intervention, participants show performance increases in working memory and executive functions. However, the potential association between habitual dietary tyrosine intake and cognitive performance has not been investigated to date.

Individualized support for informal caregivers of people with dementia - effectiveness of the German adaptation of REACH II.

Background: Individualized, outreach and structured multicomponent interventions are a promising intervention approach to relieve the burden of informal caregivers of people with dementia. In this study, we adapted and evaluated a multicomponent intervention (Resources for Enhancing Alzheimer's Caregiver Health II, REACH II), which was developed in the USA, to the German health-care system. Therefore the project is called the German adaptation of REACH II (in German: Deutsche Adaptation der REACH II, DE-REACH).

Explicit and Implicit Approach vs. Avoidance Tendencies towards High vs. Low Calorie Food Cues in Patients with Obesity and Active Binge Eating Disorder.

Patients with binge eating disorder (BED) suffer from regular food binges with loss of control. This may be due to dysfunctional approach vs. avoidance tendencies towards food in BED.

In search of features that constitute an "enriched environment" in humans: Associations between geographical properties and brain structure.

Enriched environments elicit brain plasticity in animals. In humans it is unclear which environment is enriching. Living in a city has been associated with increased amygdala activity in a stress paradigm, and being brought up in a city with increased pregenual anterior cingulate cortex (pACC) activity.

Day2day: investigating daily variability of magnetic resonance imaging measures over half a year.

Background: Most studies of brain structure and function, and their relationships to cognitive ability, have relied on inter-individual variability in magnetic resonance (MR) images. Intra-individual variability is often ignored or implicitly assumed to be equivalent to the former. Testing this assumption empirically by collecting enough data on single individuals is cumbersome and costly.

Seeing Double: Exploring the Phenomenology of Self-Reported Absence of Rivalry in Bistable Pictures.

Ambiguous images such as Rubin's vase-face can be interpreted in at least two different ways. These interpretations are typically taken to be mutually exclusive, and ambiguous images have thus served as models of perceptual competition. Here, we present data that challenges this view.

Resting-state fMRI correlations: From link-wise unreliability to whole brain stability.

The functional architecture of spontaneous BOLD fluctuations has been characterized in detail by numerous studies, demonstrating its potential relevance as a biomarker. However, the systematic investigation of its consistency is still in its infancy. Here, we analyze within- and between-subject variability and test-retest reliability of resting-state functional connectivity (FC) in a unique data set comprising multiple fMRI scans (42) from 5 subjects, and 50 single scans from 50 subjects.

Taking control! Structural and behavioural plasticity in response to game-based inhibition training in older adults.

While previous attempts to train self-control in humans have frequently failed, we set out to train response inhibition using computer-game elements. We trained older adults with a newly developed game-based inhibition training on a tablet for two months and compared them to an active and passive control group. Behavioural effects reflected in shorter stop signal response times that were observed only in the inhibition-training group.