scholarly journals Common variation in NCAN, a risk factor for bipolar disorder and schizophrenia, influences local cortical folding in schizophrenia

2013 ◽  
Vol 44 (4) ◽  
pp. 811-820 ◽  
Author(s):  
C. C. Schultz ◽  
T. W. Mühleisen ◽  
I. Nenadic ◽  
K. Koch ◽  
G. Wagner ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Risk Factor ◽  
Prefrontal Cortex ◽  
Cortical Thickness ◽  
Visual Processing ◽  
Risk Allele ◽  
Cortical Folding ◽  
Dorsolateral Prefrontal ◽  
Magnetic Resonance Imaging Mri ◽  
The Right

BackgroundRecent studies have provided strong evidence that variation in the gene neurocan (NCAN, rs1064395) is a common risk factor for bipolar disorder (BD) and schizophrenia. However, the possible relevance of NCAN variation to disease mechanisms in the human brain has not yet been explored. Thus, to identify a putative pathomechanism, we tested whether the risk allele has an influence on cortical thickness and folding in a well-characterized sample of patients with schizophrenia and healthy controls.MethodSixty-three patients and 65 controls underwent T1-weighted magnetic resonance imaging (MRI) and were genotyped for the single nucleotide polymorphism (SNP) rs1064395. Folding and thickness were analysed on a node-by-node basis using a surface-based approach (FreeSurfer).ResultsIn patients, NCAN risk status (defined by AA and AG carriers) was found to be associated with higher folding in the right lateral occipital region and at a trend level for the left dorsolateral prefrontal cortex. Controls did not show any association (p > 0.05). For cortical thickness, there was no significant effect in either patients or controls.ConclusionsThis study is the first to describe an effect of the NCAN risk variant on brain structure. Our data show that the NCAN risk allele influences cortical folding in the occipital and prefrontal cortex, which may establish disease susceptibility during neurodevelopment. The findings suggest that NCAN is involved in visual processing and top-down cognitive functioning. Both major cognitive processes are known to be disturbed in schizophrenia. Moreover, our study reveals new evidence for a specific genetic influence on local cortical folding in schizophrenia.

Structural and metabolic cerebral alterations between elderly bipolar disorder and behavioural variant frontotemporal dementia: A combined MRI-PET study

2018 ◽  
Vol 53 (5) ◽  
pp. 413-423 ◽  
Author(s):  
Giuseppe Delvecchio ◽  
Gian Mario Mandolini ◽  
Andrea Arighi ◽  
Cecilia Prunas ◽  
Carlo Massimo Mauri ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Prefrontal Cortex ◽  
Frontotemporal Dementia ◽  
Grey Matter ◽  
Temporal Cortex ◽  
Positron Emission ◽  
Dorsolateral Prefrontal ◽  
Magnetic Resonance Imaging Mri ◽  
Subcortical Regions ◽  
First Time

Background: Elderly bipolar disorder (BD) and behavioural variant of frontotemporal dementia (bvFTD) may exhibit similar symptoms and both disorders are characterized by selective abnormalities in cortical and subcortical regions that are associated with cognitive and emotional impairments. We aimed to investigate common and distinct neural substrates of BD and bvFTD by coupling, for the first time, magnetic resonance imaging (MRI) and positron emission tomography (PET) techniques. Methods: 3-Tesla MRI and 18 fluorodeoxyglucose–PET scans were acquired for 16 elderly BD patients, 23 bvFTD patients with mild cognitive impairments and 68 healthy controls (48 for PET and 20 for MRI analyses). Results: BD and bvFTD patients exhibit a different localization of grey matter reductions in the lateral prefrontal cortex, with the first group showing grey matter decrease in the ventrolateral prefrontal cortex and the latter group showing grey matter reductions in the dorsolateral prefrontal cortex as well as unique grey matter and metabolic alterations within the orbitofrontal cortex. The bvFTD group also displayed unique volumetric shrinkage in regions within the temporo-parietal network together with greater metabolic impairments within the temporal cortex and more extensive volumetric and metabolic abnormalities within the limbic lobe. Finally, while the BD group showed greater grey matter volumes in caudate nucleus, bvFTD subjects displayed lower metabolism. Conclusion: This MRI-PET study explored, for the first time to the best of our knowledge, structural and functional abnormalities in bvFTD and elderly BD patients, with the final aim of identifying the specific biological signature of these disorders, which might have important implications not only in prevention but also in differential diagnosis and treatment.

scholarly journals Cortical morphometry of the five-factor model of personality: Findings from the Human Connectome Project full sample

2018 ◽  
Author(s):  
Max Michael Owens ◽  
Courtland Hyatt ◽  
Joshua Gray ◽  
James MacKillop ◽  
Lawrence Sweet ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Personality Traits ◽  
Cortical Thickness ◽  
Factor Model ◽  
Five Factor Model ◽  
Human Connectome Project ◽  
Dorsolateral Prefrontal ◽  
The Right ◽  
Ffm Personality Traits ◽  
Area And Volume

This study is a conceptual replication of an existing large study (N = 507) on the surface-based morphometric correlates of Five-Factor Model (FFM) personality traits. Using another large sample drawn from the same population (N = 597), results were aggregated from both samples (N = 1104), providing the largest investigation into the neuroanatomical correlates of FFM personality traits to date. Multiple clusters of significant brain by personality associations were found in the aggregate sample, including one for Openness with cortical thickness in the left and right dorsolateral prefrontal cortex (DLPFC), one for Agreeableness with thickness in the left DLPFC, and one for Agreeableness with area and volume in the right DLPFC. Clusters were also found for Neuroticism with cortical surface area in the right DLPFC, for Neuroticism with cortical thickness in the DLPFC and medial prefrontal cortex, and for Neuroticism with area and volume in the cuneus. While many regions found in the prior study were confirmed in the new and full samples, others were not, highlighting the challenges in replicating even high-quality, well-powered studies. As a whole, the current results provide the strongest evidence to date on the neuroanatomical correlates of personality.

scholarly journals Null Effect of Transcranial Static Magnetic Field Stimulation over the Dorsolateral Prefrontal Cortex on Behavioral Performance in a Go/NoGo Task

2021 ◽  
Vol 11 (4) ◽  
pp. 483
Author(s):  
Tatsunori Watanabe ◽  
Nami Kubo ◽  
Xiaoxiao Chen ◽  
Keisuke Yunoki ◽  
Takuya Matsumoto ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Prefrontal Cortex ◽  
Inhibitory Control ◽  
Static Magnetic Field ◽  
Dorsolateral Prefrontal Cortex ◽  
Cortical Excitability ◽  
Control Function ◽  
Field Stimulation ◽  
Dorsolateral Prefrontal ◽  
The Right

The purpose of this pilot study was to investigate whether transcranial static magnetic field stimulation (tSMS), which can modulate cortical excitability, would influence inhibitory control function when applied over the dorsolateral prefrontal cortex (DLPFC). Young healthy adults (n = 8, mean age ± SD = 24.4 ± 4.1, six females) received the following stimulations for 30 min on different days: (1) tSMS over the left DLPFC, (2) tSMS over the right DLPFC, and (3) sham stimulation over either the left or right DLPFC. The participants performed a Go/NoGo task before, immediately after, and 10 min after the stimulation. They were instructed to extend the right wrist in response to target stimuli. We recorded the electromyogram from the right wrist extensor muscles and analyzed erroneous responses (false alarm and missed target detection) and reaction times. As a result, 50% of the participants made erroneous responses, and there were five erroneous responses in total (0.003%). A series of statistical analyses revealed that tSMS did not affect the reaction time. These preliminary findings suggest the possibility that tSMS over the DLPFC is incapable of modulating inhibitory control and/or that the cognitive load imposed in this study was insufficient to detect the effect.

scholarly journals Single-Pulse Transcranial Magnetic Stimulation-Evoked Potential Amplitudes and Latencies in the Motor and Dorsolateral Prefrontal Cortex among Young, Older Healthy Participants, and Schizophrenia Patients

2021 ◽  
Vol 11 (1) ◽  
pp. 54
Author(s):  
Yoshihiro Noda ◽  
Mera S. Barr ◽  
Reza Zomorrodi ◽  
Robin F. H. Cash ◽  
Pantelis Lioumis ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Evoked Potential ◽  
Single Pulse ◽  
Signal Propagation ◽  
Lower Amplitude ◽  
Dorsolateral Prefrontal ◽  
The Right

Background: The combination of transcranial magnetic stimulation (TMS) with electroencephalography (EEG) allows for non-invasive investigation of cortical response and connectivity in human cortex. This study aimed to examine the amplitudes and latencies of each TMS-evoked potential (TEP) component induced by single-pulse TMS (spTMS) to the left motor (M1) and dorsolateral prefrontal cortex (DLPFC) among healthy young participants (YNG), older participants (OLD), and patients with schizophrenia (SCZ). Methods: We compared the spatiotemporal characteristics of TEPs induced by spTMS among the groups. Results: Compared to YNG, M1-spTMS induced lower amplitudes of N45 and P180 in OLD and a lower amplitude of P180 in SCZ, whereas the DLPFC-spTMS induced a lower N45 in OLD. Further, OLD demonstrated latency delays in P60 after M1-spTMS and in N45-P60 over the right central region after left DLPFC-spTMS, whereas SCZ demonstrated latency delays in N45-P60 over the midline and right central regions after DLPFC-spTMS. Conclusions: These findings suggest that inhibitory and excitatory mechanisms mediating TEPs may be altered in OLD and SCZ. The amplitude and latency changes of TEPs with spTMS may reflect underlying neurophysiological changes in OLD and SCZ, respectively. The spTMS administered to M1 and the DLPFC can probe cortical functions by examining TEPs. Thus, TMS-EEG can be used to study changes in cortical connectivity and signal propagation from healthy to pathological brains.

scholarly journals The role of prefrontal cortex in working memory: examining the contents of consciousness

1998 ◽  
Vol 353 (1377) ◽  
pp. 1819-1828 ◽  
Author(s):  
◽  
S. M. Courtney ◽  
L. Petit ◽  
J. V. Haxby ◽  
L. G. Ungerleider
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Visual Processing ◽  
Right Hemisphere ◽  
Functional Organization ◽  
Spatial Working Memory ◽  
Domain Specificity ◽  
Long Term Memory ◽  
Present Evidence ◽  
The Right

Working memory enables us to hold in our ‘mind's eye’ the contents of our conscious awareness, even in the absence of sensory input, by maintaining an active representation of information for a brief period of time. In this review we consider the functional organization of the prefrontal cortex and its role in this cognitive process. First, we present evidence from brain–imaging studies that prefrontal cortex shows sustained activity during the delay period of visual working memory tasks, indicating that this cortex maintains on–line representations of stimuli after they are removed from view. We then present evidence for domain specificity within frontal cortex based on the type of information, with object working memory mediated by more ventral frontal regions and spatial working memory mediated by more dorsal frontal regions. We also propose that a second dimension for domain specificity within prefrontal cortex might exist for object working memory on the basis of the type of representation, with analytic representations maintained preferentially in the left hemisphere and image–based representations maintained preferentially in the right hemisphere. Furthermore, we discuss the possibility that there are prefrontal areas brought into play during the monitoring and manipulation of information in working memory in addition to those engaged during the maintenance of this information. Finally, we consider the relationship of prefrontal areas important for working memory, both to posterior visual processing areas and to prefrontal areas associated with long–term memory.

scholarly journals Influence of Atomoxetine on Relationship Between ADHD Symptoms and Prefrontal Cortex Activity During Task Execution in Adult Patients

2021 ◽  
Vol 15 ◽  
Author(s):  
Atsunori Sugimoto ◽  
Yutaro Suzuki ◽  
Kiyohiro Yoshinaga ◽  
Naoki Orime ◽  
Taketsugu Hayashi ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Rating Scales ◽  
Clinical Symptoms ◽  
Adult Patients ◽  
Adhd Symptoms ◽  
Analytical Strategy ◽  
Positive Correlation ◽  
Dorsolateral Prefrontal ◽  
The Right

Objective: We conducted this non-randomized prospective interventional study to clarify the relationship between improved attention-deficit hyperactivity disorder (ADHD) symptoms and regional brain activity.Methods: Thirty-one adult patients underwent near-infrared spectroscopy examinations during a go/no-go task, both before and 8 weeks after atomoxetine administration.Results: Clinical symptoms, neuropsychological results of the go/no-go task, and bilateral lateral prefrontal activity significantly changed. A positive correlation was observed between right dorsolateral prefrontal cortex activity and Conners’ Adult ADHD Rating Scales scores. Before atomoxetine administration, no correlations between prefrontal cortex activity and clinical symptoms were observed in all cases. When participants were divided into atomoxetine-responder and non-responder groups, a positive correlation was observed between prefrontal cortex activity and clinical symptoms in the non-responder group before treatment but not in the responder group, suggesting that non-responders can activate the prefrontal cortex without atomoxetine.Conclusions: Individuals with increased ADHD symptoms appear to recruit the right dorsolateral prefrontal cortex more strongly to perform the same task than those with fewer symptoms. In clinical settings, individuals with severe symptoms are often observed to perform more difficultly when performing the tasks which individuals with mild symptoms can perform easily. The atomoxetine-responder group was unable to properly activate the right dorsolateral prefrontal cortex when necessary, and the oral administration of atomoxetine enabled these patients to activate this region. In brain imaging studies of heterogeneous syndromes such as ADHD, the analytical strategy used in this study, involving drug-responsivity grouping, may effectively increase the signal-to-noise ratio.

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