Helping You Find Full Text Journal Articles

Search Results:

Author: Heike Tost (85)


Jan
2018

The development of advanced neuroimaging techniques and their deployment in large cohorts has enabled an assessment of functional and structural brain network architecture at an unprecedented level of detail. Across many temporal and spatial scales, network neuroscience has emerged as a central focus of intellectual efforts, seeking meaningful descriptions of brain networks and explanatory sets of network features that underlie circuit function in health and dysfunction in disease. However, the tools of network science commonly deployed provide insight into brain function at a fundamentally descriptive level, often failing to identify (patho-)physiological mechanisms that link system-level phenomena to the multiple hierarchies of brain function.

View Full Text PDF Listings View primary source full text article PDFs.

Jul
2017

Migration status is one of the best-established risk factors for schizophrenia. An increase in risk is observed in both first- and second-generation immigrants, with a varying magnitude depending on the ethnic background of the individuals. The underlying mechanisms for the increased risk are only recently coming into focus.

View Full Text PDF Listings View primary source full text article PDFs.

Sep
2017

The rs1625579 variant near the microRNA-137 (MIR137) gene is one of the best-supported schizophrenia variants in genome-wide association studies (GWAS), and microRNA-137 functionally regulates other GWAS identified schizophrenia risk variants. Schizophrenia patients with the MIR137 rs1625579 risk genotype (homozygous for the schizophrenia risk variant) also have aberrant brain structure. It is unclear if the effect of MIR137 among schizophrenia patients is due to potential epistasis with genetic risk for schizophrenia or other factors of the disorder.

View Full Text PDF Listings View primary source full text article PDFs.

Sep
2017

Although borderline personality disorder (BPD)-one of the most common, burdensome, and costly psychiatric conditions-is characterized by repeated interpersonal conflict and instable relationships, the neurobiological mechanism of social interactive deficits remains poorly understood.
To apply recent advancements in the investigation of 2-person human social interaction to investigate interaction difficulties among people with BPD.
Cross-brain information flow in BPD was examined from May 25, 2012, to December 4, 2015, in pairs of participants studied in 2 linked functional magnetic resonance imaging scanners in a university setting.

View Full Text PDF Listings View primary source full text article PDFs.

Dec
1969

The EU-AIMS Longitudinal European Autism Project (LEAP) is to date the largest multi-centre, multi-disciplinary observational study on biomarkers for autism spectrum disorder (ASD). The current paper describes the clinical characteristics of the LEAP cohort and examines age, sex and IQ differences in ASD core symptoms and common co-occurring psychiatric symptoms. A companion paper describes the overall design and experimental protocol and outlines the strategy to identify stratification biomarkers.

View Full Text PDF Listings View primary source full text article PDFs.

Dec
1969

The tremendous clinical and aetiological diversity among individuals with autism spectrum disorder (ASD) has been a major obstacle to the development of new treatments, as many may only be effective in particular subgroups. Precision medicine approaches aim to overcome this challenge by combining pathophysiologically based treatments with stratification biomarkers that predict which treatment may be most beneficial for particular individuals. However, so far, we have no single validated stratification biomarker for ASD.

View Full Text PDF Listings View primary source full text article PDFs.

Jan
2018

The serotonin transporter-linked polymorphic region 5-HTTLPR is a key genetic regulator of 5-HTT expression in the human brain where the short allele S has been implicated in emotion dysregulation. However, the neural mechanism underlying the association between this variant and emotion processing is still unclear. Earlier studies suggested an effect of 5-HTTLPR on amygdala activation during emotional face processing.

View Full Text PDF Listings View primary source full text article PDFs.

Aug
2017

Previous research suggests a role of the dorsomedial prefrontal cortex (dmPFC) in metacognitive representation of social information, while the right posterior superior temporal sulcus (pSTS) has been linked to social perception. This study targeted these functional roles in the context of spontaneous mentalizing. An animated shapes task was presented to 46 subjects during functional magnetic resonance imaging.

View Full Text PDF Listings View primary source full text article PDFs.

Jun
2017

Threshold-free cluster enhancement (TFCE) is a sensitive means to incorporate spatial neighborhood information in neuroimaging studies without using arbitrary thresholds. The majority of methods have applied TFCE to voxelwise data. The need to understand the relationship among multiple variables and imaging modalities has become critical.

View Full Text PDF Listings View primary source full text article PDFs.

Jul
2017

Imbalances in cortico-limbic activity and functional connectivity (FC) supposedly underlie biased emotional processing and present putative intermediate phenotypes (IPs) for major depressive disorder (MDD). To prove the validity of these IPs, we assessed them in familial risk. In 70 healthy first-degree relatives of MDD patients and 70 controls, brain activity and seed-based amygdala FC were assessed during an implicit emotional processing task for fMRI containing angry and fearful faces.

View Full Text PDF Listings View primary source full text article PDFs.

Sep
2017

Altered connectivity of dorsolateral prefrontal cortex (DLPFC) and hippocampus during working memory is considered an intermediate phenotype for schizophrenia (SCZ), but the relevance for other mental disorders with shared genetic background remains unknown. Here we investigated its presence in unaffected first-degree relatives of patients with bipolar disorder (BD) or major depressive disorder (MDD). Furthermore, we aimed to provide an independent replication of this phenotype in first-degree relatives of SCZ patients.

View Full Text PDF Listings View primary source full text article PDFs.

Nov
2016

Self-reporting is a well-established approach within the medical and psychological sciences. In order to avoid recall bias, i.e.

View Full Text PDF Listings View primary source full text article PDFs.

Apr
2017

The association between physical activity and mood is of major importance to increase physical activity as a prevention strategy for noncommunicable diseases and to improve mental health. Unfortunately, existing studies examining how physical activity and mood wax and wane within persons over time in everyday life do show ambiguous findings. Taking a closer look at these studies reveals that the aggregation levels differ tremendously.

View Full Text PDF Listings View primary source full text article PDFs.

Nov
2016

Schizophrenia is increasingly recognized as a disorder of distributed neural dynamics, but the molecular and genetic contributions are poorly understood. Recent work highlights a role for altered N-methyl-d-aspartate (NMDA) receptor signaling and related impairments in the excitation-inhibitory balance and synchrony of large-scale neural networks. Here, we combined a pharmacological intervention with novel techniques from dynamic network neuroscience applied to functional magnetic resonance imaging (fMRI) to identify alterations in the dynamic reconfiguration of brain networks related to schizophrenia genetic risk and NMDA receptor hypofunction.

View Full Text PDF Listings View primary source full text article PDFs.

Dec
1969

The debilitating effects of social dysfunction in many psychiatric disorders prompt the need for systems-level biomarkers of social abilities that can be applied in clinical populations and longitudinal studies. A promising neuroimaging approach is the animated shapes paradigm based on so-called Frith-Happé animations (FHAs) which trigger spontaneous mentalizing with minimal cognitive demands. Here, we presented FHAs during functional magnetic resonance imaging to 46 subjects and examined the specificity and sensitivity of the elicited social brain responses.

View Full Text PDF Listings View primary source full text article PDFs.

Apr
2017

Several studies in patients with schizophrenia reported a marked reduction in sleep spindle activity. To investigate whether the reduction may be linked to genetic risk of the illness, we analysed sleep spindle activity in healthy volunteers, patients with schizophrenia and first-degree relatives, who share an enriched set of schizophrenia susceptibility genes. We further investigated the correlation of spindle activity with cognitive function in first-degree relatives and whether spindle abnormalities affect both fast (12-15 Hz) and slow (9-12 Hz) sleep spindles.

View Full Text PDF Listings View primary source full text article PDFs.

Dec
1969

A physically active lifestyle has been related to positive health outcomes and high life expectancy, but the underlying psychological mechanisms maintaining physical activity are rarely investigated. Tremendous technological progress yielding sophisticated methodological approaches, i.e.

View Full Text PDF Listings View primary source full text article PDFs.

Jun
2016

Although deficits in emotional processing are prominent in schizophrenia, it has been difficult to identify neural mechanisms related to the genetic risk for this highly heritable illness. Prior studies have not found consistent regional activation or connectivity alterations in first-degree relatives compared with healthy controls, suggesting that a more comprehensive search for connectomic biomarkers is warranted.
To identify a potential systems-level intermediate phenotype linked to emotion processing in schizophrenia and to examine the psychological association, task specificity, test-retest reliability, and clinical validity of the identified phenotype.

View Full Text PDF Listings View primary source full text article PDFs.

View Full Text PDF Listings View primary source full text article PDFs.

Dec
1969

Multivariate pattern analysis can reveal new information from neuroimaging data to illuminate human cognition and its disturbances. Here, we develop a methodological approach, based on multivariate statistical/machine learning and time series analysis, to discern cognitive processing stages from functional magnetic resonance imaging (fMRI) blood oxygenation level dependent (BOLD) time series. We apply this method to data recorded from a group of healthy adults whilst performing a virtual reality version of the delayed win-shift radial arm maze (RAM) task.

View Full Text PDF Listings View primary source full text article PDFs.

Oct
2015

The developing human brain is shaped by environmental exposures--for better or worse. Many exposures relevant to mental health are genuinely social in nature or believed to have social subcomponents, even those related to more complex societal or area-level influences. The nature of how these social experiences are embedded into the environment may be crucial.

View Full Text PDF Listings View primary source full text article PDFs.

Apr
2016

Convergent evidence implicates regional neural responses to reward anticipation in the pathogenesis of several psychiatric disorders, such as schizophrenia, where blunted ventral striatal responses to positive reward are observed in patients and at-risk populations. In vivo oxygen amperometry measurements in the ventral striatum in awake, behaving rats reveal reward-related tissue oxygen changes that closely parallel blood oxygen level dependent (BOLD) signal changes observed in human functional magnetic resonance imaging (fMRI), suggesting that a cross-species approach targeting this mechanism might be feasible in psychopharmacology. The present study explored modulatory effects of acute, subanaesthetic doses of ketamine-a pharmacological model widely used in psychopharmacological research, both preclinically and clinically-on ventral striatum activity during performance of a reward anticipation task in both species, using fMRI in humans and in vivo oxygen amperometry in rats.

View Full Text PDF Listings View primary source full text article PDFs.

Jan
2016

Working memory genetics in schizophrenia and related disorders: An RDoC perspective.

Am J Med Genet B Neuropsychiatr Genet 2016 Jan 14;171B(1):121-31. Epub 2015 Sep 14.
Emanuel Schwarz, Heike Tost, Andreas Meyer-Lindenberg
Improved classification of mental disorders through neurobiological measures will require a set of traits that map to transdiagnostic subgroups of patients and align with heritable, core psychopathological processes at the center of the disorders of interest. A promising candidate is working memory (WM) function, for which deficits have been reported across multiple diagnostic entities including schizophrenia, bipolar disorder, ADHD, autism, and major depressive disorder. Here we review genetic working memory associations and their brain functional correlates from the perspective of identifying patient subgroups across conventional diagnostic boundaries, explore the utility of multimodal investigations integrating functional information at the neural systems level and explore potential limitations as well as future directions for research.

View Full Text PDF Listings View primary source full text article PDFs.

Feb
2016

As evidenced by a multitude of studies, abnormalities in Theory of Mind (ToM) and its neural processing might constitute an intermediate phenotype of schizophrenia. If so, neural alterations during ToM should be observable in unaffected relatives of patients as well, since they share a considerable amount of genetic risk. While behaviorally, impaired ToM function is confirmed meta-analytically in relatives, evidence on aberrant function of the neural ToM network is sparse and inconclusive.

View Full Text PDF Listings View primary source full text article PDFs.

Sep
2015

The brain is an inherently dynamic system, and executive cognition requires dynamically reconfiguring, highly evolving networks of brain regions that interact in complex and transient communication patterns. However, a precise characterization of these reconfiguration processes during cognitive function in humans remains elusive. Here, we use a series of techniques developed in the field of "dynamic network neuroscience" to investigate the dynamics of functional brain networks in 344 healthy subjects during a working-memory challenge (the "n-back" task).

View Full Text PDF Listings View primary source full text article PDFs.

Feb
2016

The search for quantifiable biological mediators of genetic risk or 'intermediate phenotypes' is an essential strategy in psychiatric neuroscience and a useful tool for exploring the complex relationships between genes, neural circuits and behaviors. In recent years, the examination of connectivity-based intermediate phenotypes has gained increasing popularity in the study of schizophrenia, a brain disorder that manifests in early adulthood and disturbs a wide range of neural network functions. To date, several potential connectivity phenotypes have been identified that link neuroimaging measures of neural circuit interaction to genetic susceptibility for schizophrenia.

View Full Text PDF Listings View primary source full text article PDFs.

Nov
2015

Aberrant prefrontal-hippocampal (PFC-HC) connectivity is disrupted in several psychiatric and at-risk conditions. Advances in rodent functional imaging have opened the possibility that this phenotype could serve as a translational imaging marker for psychiatric research. Recent evidence from functional magnetic resonance imaging (fMRI) studies has indicated an increase in PFC-HC coupling during working-memory tasks in both schizophrenic patients and at-risk populations, in contrast to a decrease in resting-state PFC-HC connectivity.

View Full Text PDF Listings View primary source full text article PDFs.

Oct
2015

The application of global signal regression (GSR) to resting-state functional magnetic resonance imaging data and its usefulness is a widely discussed topic. In this article, we report an observation of segregated distribution of amygdala resting-state functional connectivity (rs-FC) within the fusiform gyrus (FFG) as an effect of GSR in a multi-center-sample of 276 healthy subjects. Specifically, we observed that amygdala rs-FC was distributed within the FFG as distinct anterior versus posterior clusters delineated by positive versus negative rs-FC polarity when GSR was performed.

View Full Text PDF Listings View primary source full text article PDFs.

Dec
1969

White matter (WM) magnetic resonance imaging (MRI) hyperintensities are common in Alzheimer's disease (AD), but their pathophysiological relevance and relationship to genetic factors are unclear. In the present study, we investigated potential apolipoprotein E (APOE)-dependent effects on the extent and cognitive impact of WM hyperintensities in patients with AD.
WM hyperintensity volume on fluid-attenuated inversion recovery images of 201 patients with AD (128 carriers and 73 non-carriers of the APOE ε4 risk allele) was determined globally as well as regionally with voxel-based lesion mapping.

View Full Text PDF Listings View primary source full text article PDFs.

Apr
2015

Social interactions are fundamental for human behavior, but the quantification of their neural underpinnings remains challenging. Here, we used hyperscanning functional MRI (fMRI) to study information flow between brains of human dyads during real-time social interaction in a joint attention paradigm. In a hardware setup enabling immersive audiovisual interaction of subjects in linked fMRI scanners, we characterize cross-brain connectivity components that are unique to interacting individuals, identifying information flow between the sender's and receiver's temporoparietal junction.

View Full Text PDF Listings View primary source full text article PDFs.

Aug
2015

The cortisol rise after awakening (cortisol awakening response, CAR) is a core biomarker of hypothalamic-pituitary-adrenal (HPA) axis regulation related to psychosocial stress and stress-related psychiatric disorders. However, the neural regulation of the CAR has not been examined in humans. Here, we studied neural regulation related to the CAR in a sample of 25 healthy human participants using an established psychosocial stress paradigm together with multimodal functional and structural (voxel-based morphometry) magnetic resonance imaging.

View Full Text PDF Listings View primary source full text article PDFs.

Jun
2015

Hippocampal-prefrontal cortex (HC-PFC) interactions are implicated in working memory (WM) and altered in psychiatric conditions with cognitive impairment such as schizophrenia. While coupling between both structures is crucial for WM performance in rodents, evidence from human studies is conflicting and translation of findings is complicated by the use of differing paradigms across species. We therefore used functional magnetic resonance imaging together with a spatial WM paradigm adapted from rodent research to examine HC-PFC coupling in humans.

View Full Text PDF Listings View primary source full text article PDFs.

Dec
2014

Amygdala function is of high interest for cognitive, social and psychiatric neuroscience, emphasizing the need for reliable assessments in humans. Previous work has indicated unsatisfactorily low within-subject reliability of amygdala activation fMRI measures. Based on basic science evidence for strong habituation of amygdala response to repeated stimuli, we investigated whether a quantification of habituation provides additional information beyond the usual estimate of the overall mean activity.

View Full Text PDF Listings View primary source full text article PDFs.

Nov
2014

Obesity has emerged as a leading health threat but its biological basis remains insufficiently known, hampering the search for novel treatments. Here, we study oleoylethanolamide, a naturally occurring lipid that has been clearly implicated in weight regulation in animals. However, its role for weight regulation and obesity in humans is still unclear.

View Full Text PDF Listings View primary source full text article PDFs.

View Full Text PDF Listings View primary source full text article PDFs.

Jun
2015

Patients suffering from bipolar affective disorder show deficits in working memory functions. In a previous functional magnetic resonance imaging study, we observed an abnormal hyperactivity of the amygdala in bipolar patients during articulatory rehearsal in verbal working memory. In the present study, we investigated the dynamic neurofunctional interactions between the right amygdala and the brain systems that underlie verbal working memory in both bipolar patients and healthy controls.

View Full Text PDF Listings View primary source full text article PDFs.

Dec
1969

Although a heritable contribution to risk for major depressive disorder (MDD) has been established and neural alterations in patients have been identified through neuroimaging, it is unclear which brain abnormalities are related to genetic risk. Studies on brain structure of high-risk subjects - such as individuals carrying a familial liability for the development of MDD - can provide information on the potential usefulness of these measures as intermediate phenotypes of MDD.
63 healthy first-degree relatives of patients with MDD and 63 healthy controls underwent structural magnetic resonance imaging.

View Full Text PDF Listings View primary source full text article PDFs.

Jul
2014

Functional interactions between the dorsolateral prefrontal cortex and hippocampus during working memory have been studied extensively as an intermediate phenotype for schizophrenia. Coupling abnormalities have been found in patients, their unaffected siblings, and carriers of common genetic variants associated with schizophrenia, but the global genetic architecture of this imaging phenotype is unclear. To achieve genome-wide hypothesis-free identification of genes and pathways associated with prefrontal-hippocampal interactions, we combined gene set enrichment analysis with whole-genome genotyping and functional magnetic resonance imaging data from 269 healthy German volunteers.

View Full Text PDF Listings View primary source full text article PDFs.

Jan
2015

Urban upbringing has consistently been associated with schizophrenia, but which specific environmental exposures are reflected by this epidemiological observation and how they impact the developing brain to increase risk is largely unknown. On the basis of prior observations of abnormal functional brain processing of social stress in urban-born humans and preclinical evidence for enduring structural brain effects of early social stress, we investigated a possible morphological correlate of urban upbringing in human brain. In a sample of 110 healthy subjects studied with voxel-based morphometry, we detected a strong inverse correlation between early-life urbanicity and gray matter (GM) volume in the right dorsolateral prefrontal cortex (DLPFC, Brodmann area 9).

View Full Text PDF Listings View primary source full text article PDFs.

Jul
2014

Identifying gene-environment interactions in schizophrenia: contemporary challenges for integrated, large-scale investigations.

Schizophr Bull 2014 Jul 24;40(4):729-36. Epub 2014 May 24.
, Jim van Os, Bart P Rutten, Inez Myin-Germeys, Philippe Delespaul, Wolfgang Viechtbauer, Catherine van Zelst, Richard Bruggeman, Ulrich Reininghaus, Craig Morgan, Robin M Murray, Marta Di Forti, Philip McGuire, Lucia R Valmaggia, Matthew J Kempton, Charlotte Gayer-Anderson, Kathryn Hubbard, Stephanie Beards, Simona A Stilo, Adanna Onyejiaka, Francois Bourque, Gemma Modinos, Stefania Tognin, Maria Calem, Michael C O'Donovan, Michael J Owen, Peter Holmans, Nigel Williams, Nicholas Craddock, Alexander Richards, Isla Humphreys, Andreas Meyer-Lindenberg, F Markus Leweke, Heike Tost, Ceren Akdeniz, Cathrin Rohleder, J Malte Bumb, Emanuel Schwarz, Köksal Alptekin, Alp Üçok, Meram Can Saka, E Cem Atbaşoğlu, Sinan Gülöksüz, Guvem Gumus-Akay, Burçin Cihan, Hasan Karadağ, Haldan Soygür, Eylem Şahin Cankurtaran, Semra Ulusoy, Berna Akdede, Tolga Binbay, Ahmet Ayer, Handan Noyan, Gülşah Karadayı, Elçin Akturan, Halis Ulaş, Celso Arango, Mara Parellada, Miguel Bernardo, Julio Sanjuán, Julio Bobes, Manuel Arrojo, Jose Luis Santos, Pedro Cuadrado, José Juan Rodríguez Solano, Angel Carracedo, Enrique García Bernardo, Laura Roldán, Gonzalo López, Bibiana Cabrera, Sabrina Cruz, Eva Ma Díaz Mesa, María Pouso, Estela Jiménez, Teresa Sánchez, Marta Rapado, Emiliano González, Covadonga Martínez, Emilio Sánchez, Ma Soledad Olmeda, Lieuwe de Haan, Eva Velthorst, Mark van der Gaag, Jean-Paul Selten, Daniella van Dam, Elsje van der Ven, Floor van der Meer, Elles Messchaert, Tamar Kraan, Nadine Burger, Marion Leboyer, Andrei Szoke, Franck Schürhoff, Pierre-Michel Llorca, Stéphane Jamain, Andrea Tortelli, Flora Frijda, Jeanne Vilain, Anne-Marie Galliot, Grégoire Baudin, Aziz Ferchiou, Jean-Romain Richard, Ewa Bulzacka, Thomas Charpeaud, Anne-Marie Tronche, Marc De Hert, Ruud van Winkel, Jeroen Decoster, Catherine Derom, Evert Thiery, Nikos C Stefanis, Gabriele Sachs, Harald Aschauer, Iris Lasser, Bernadette Winklbaur, Monika Schlögelhofer, Anita Riecher-Rössler, Stefan Borgwardt, Anna Walter, Fabienne Harrisberger, Renata Smieskova, Charlotte Rapp, Sarah Ittig, Fabienne Soguel-dit-Piquard, Erich Studerus, Joachim Klosterkötter, Stephan Ruhrmann, Julia Paruch, Dominika Julkowski, Desiree Hilboll, Pak C Sham, Stacey S Cherny, Eric Y H Chen, Desmond D Campbell, Miaoxin Li, Carlos María Romeo-Casabona, Aitziber Emaldi Cirión, Asier Urruela Mora, Peter Jones, James Kirkbride, Mary Cannon, Dan Rujescu, Ilaria Tarricone, Domenico Berardi, Elena Bonora, Marco Seri, Thomas Marcacci, Luigi Chiri, Federico Chierzi, Viviana Storbini, Mauro Braca, Maria Gabriella Minenna, Ivonne Donegani, Angelo Fioritti, Daniele La Barbera, Caterina Erika La Cascia, Alice Mulè, Lucia Sideli, Rachele Sartorio, Laura Ferraro, Giada Tripoli, Fabio Seminerio, Anna Maria Marinaro, Patrick McGorry, Barnaby Nelson, G Paul Amminger, Christos Pantelis, Paulo R Menezes, Cristina M Del-Ben, Silvia H Gallo Tenan, Rosana Shuhama, Mirella Ruggeri, Sarah Tosato, Antonio Lasalvia, Chiara Bonetto, Elisa Ira, Merete Nordentoft, Marie-Odile Krebs, Neus Barrantes-Vidal, Paula Cristóbal, Thomas R Kwapil, Elisa Brietzke, Rodrigo A Bressan, Ary Gadelha, Nadja P Maric, Sanja Andric, Marina Mihaljevic, Tijana Mirjanic
Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular genetic variants is small. There are now also a limited number of studies that have investigated molecular genetic candidate gene-environment interactions (G × E), however, so far, thorough replication of findings is rare and G × E research still faces several conceptual and methodological challenges. In this article, we aim to review these recent developments and illustrate how integrated, large-scale investigations may overcome contemporary challenges in G × E research, drawing on the example of a large, international, multi-center study into the identification and translational application of G × E in schizophrenia.

View Full Text PDF Listings View primary source full text article PDFs.

Jun
2014

Relative risk for the brain disorder schizophrenia is more than doubled in ethnic minorities, an effect that is evident across countries and linked to socially relevant cues such as skin color, making ethnic minority status a well-established social environmental risk factor. Pathoepidemiological models propose a role for chronic social stress and perceived discrimination for mental health risk in ethnic minorities, but the neurobiology is unexplored.
To study neural social stress processing, using functional magnetic resonance imaging, and associations with perceived discrimination in ethnic minority individuals.

View Full Text PDF Listings View primary source full text article PDFs.

Jul
2014

Variation in the CACNA1C gene has consistently been associated with psychosis in genome wide association studies. We have previously shown in a sample of n=110 healthy subjects that carriers of the CACNA1C rs1006737 risk variant exhibit hippocampal and perigenual anterior cingulate dysfunction (pgACC) during episodic memory recall. Here, we aimed to replicate our results, by testing for the effects of the rs1006737 risk variant in a new large cohort of healthy controls.

View Full Text PDF Listings View primary source full text article PDFs.

Apr
2014

Schizophrenia is a severe and complex brain disorder that usually manifests in early adulthood and disturbs a wide range of human functions. More than 100 years after its initial description, the pathophysiology of the disorder is still incompletely understood. Many epidemiological studies strongly suggest a complex interaction between genetic and environmental risk factors for the development of the disorder.

View Full Text PDF Listings View primary source full text article PDFs.

May
2014

Attenuated ventral striatal response during reward anticipation is a core feature of schizophrenia that is seen in prodromal, drug-naive, and chronic schizophrenic patients. Schizophrenia is highly heritable, raising the possibility that this phenotype is related to the genetic risk for the disorder.
To examine a large sample of healthy first-degree relatives of schizophrenic patients and compare their neural responses to reward anticipation with those of carefully matched controls without a family psychiatric history.

View Full Text PDF Listings View primary source full text article PDFs.

Oct
2014

Evidence has emerged indicating that the ε4 allele of APOE and PICALM interact in conferring risk of Alzheimer's disease (AD). The biologic basis of this interaction is unclear, but it is likely to have phenotypic relevance and contribute to the structural and clinical heterogeneity of AD.
The aim of this study was to investigate interaction effects of the APOE ε4 allele and the alleles at the single-nucleotide polymorphism rs3851179 located in the PICALM locus.

View Full Text PDF Listings View primary source full text article PDFs.

Jan
2014

The neuregulin 3 gene (NRG3) plays pleiotropic roles in neurodevelopment and is a putative susceptibility locus for schizophrenia. Specifically, the T allele of NRG3 rs10748842 has been associated with illness risk, altered cognitive function, and the expression of a novel splice isoform in prefrontal cortex (PFC), but the neural system effects are unexplored. Here, we report an association between rs10748842 and PFC physiology as measured by functional magnetic resonance imaging of human working memory performance, where a convincing link between increased genetic risk for schizophrenia and increased activation in some PFC areas has been established.

View Full Text PDF Listings View primary source full text article PDFs.

Sep
2014

Variation in CACNA1C has consistently been associated with psychiatric disease in genome-wide association studies. We have previously shown that healthy carriers of the CACNA1C rs1006737 risk variant exhibit hippocampal and perigenual anterior cingulate (pgACC) dysfunction during episodic memory recall. To test whether this brain systems-level abnormality is a potential intermediate phenotype for psychiatric disorder, we studied unaffected relatives of patients with bipolar disorder, major depression, and schizophrenia.

View Full Text PDF Listings View primary source full text article PDFs.

Jan
2014

In a small fraction of patients with schizophrenia or autism, alleles of copy-number variants (CNVs) in their genomes are probably the strongest factors contributing to the pathogenesis of the disease. These CNVs may provide an entry point for investigations into the mechanisms of brain function and dysfunction alike. They are not fully penetrant and offer an opportunity to study their effects separate from that of manifest disease.

View Full Text PDF Listings View primary source full text article PDFs.

Jan
2014

The investigation of the brain connectome with functional magnetic resonance imaging (fMRI) and graph theory analyses has recently gained much popularity, but little is known about the robustness of these properties, in particular those derived from active fMRI tasks. Here, we studied the test-retest reliability of brain graphs calculated from 26 healthy participants with three established fMRI experiments (n-back working memory, emotional face-matching, resting state) and two parcellation schemes for node definition (AAL atlas, functional atlas proposed by Power et al.).

View Full Text PDF Listings View primary source full text article PDFs.

Dec
1969

The E4 isoform of the APOE genotype is the most significant genetic risk factor for sporadic Alzheimer's disease (AD) and has recently been found to modulate disease expression in patients with AD.
To investigate APOE-dependent cognitive and structural phenotypes in subjects with mild cognitive impairment who converted to AD within the following three years.
Subjects converting to AD (n = 63) were compared to a control group with stable mild cognitive impairment (n = 131).

View Full Text PDF Listings View primary source full text article PDFs.

Back to top