frontal pole
Recently Published Documents


TOTAL DOCUMENTS

170
(FIVE YEARS 81)

H-INDEX

24
(FIVE YEARS 3)

Author(s):  
Matti Gärtner ◽  
Anne Weigand ◽  
Milan Scheidegger ◽  
Mick Lehmann ◽  
Patrik O. Wyss ◽  
...  

AbstractKetamine exerts its rapid antidepressant effects via modulation of the glutamatergic system. While numerous imaging studies have investigated the effects of ketamine on a functional macroscopic brain level, it remains unclear how altered glutamate metabolism and changes in brain function are linked. To shed light on this topic we here conducted a multimodal imaging study in healthy volunteers (N = 23) using resting state fMRI and proton (1H) magnetic resonance spectroscopy (MRS) to investigate linkage between metabolic and functional brain changes induced by ketamine. Subjects were investigated before and during an intravenous ketamine infusion. The MRS voxel was placed in the pregenual anterior cingulate cortex (pgACC), as this region has been repeatedly shown to be involved in ketamine’s effects. Our results showed functional connectivity changes from the pgACC to the right frontal pole and anterior mid cingulate cortex (aMCC). Absolute glutamate and glutamine concentrations in the pgACC did not differ significantly from baseline. However, we found that stronger pgACC activation during ketamine was linked to lower glutamine concentration in this region. Furthermore, reduced functional connectivity between pgACC and aMCC was related to increased pgACC activation and reduced glutamine. Our results thereby demonstrate how multimodal investigations in a single brain region could help to advance our understanding of the association between metabolic and functional changes.


2021 ◽  
pp. JN-RM-1522-21
Author(s):  
RC Lapate ◽  
IC Ballard ◽  
MK Heckner ◽  
M D’Esposito

2021 ◽  
Author(s):  
Stefania Ferraro ◽  
Jean Paul Medina ◽  
Anna Nigri ◽  
Luca Giani ◽  
Greta Demichelis ◽  
...  

BACKGROUND: Converging evidence suggests that anatomical and functional mesocorticolimbic abnormalities support the chronicization of pain disorders. METHODS: We mapped structural and functional alterations of the mesocorticolimbic system in a sample of chronic cluster headache (cCH) patients (n = 28) in comparison to age and sex-matched healthy individuals (n=28) employing structural MRI and resting-state functional MRI (rs-fMRI). RESULTS: Univariate logistic regression models showed that several of the examined structures/areas (i.e., the bilateral nucleus accumbens, ventral diencephalon, hippocampus, and frontal pole, and the right amygdala) differentiated cCH patients from healthy individuals (p<0.05, uncorrected). Specifically, all the significant structures/areas had increased volumes in cCH patients compared to healthy individuals. The examination of the groups suffering from left and right-sided cranial attacks showed a lateralization effect: ipsilateral to the pain ventral diencephalic regions and contralateral to the pain nucleus accumbens discriminated cCH patients from healthy individuals. The rs-fMRI data analyses showed that cCH patients compared to CTRL individuals present robust reduced functional connectivity in the right frontal pole-right amygdala pathway (p<0.05, FDR-corrected). CONCLUSION: Our results showed that cCH patients present anatomical and functional maladaptation of the mesocorticolimbic system, with functional data indicating a possible prefrontal areas' failure to modulate the mesolimbic structures. These results were opposite to what we hypothesized based on the previous literature on chronic pain conditions. Future studies should assess whether the observed mesocorticolimbic abnormalities are due to the neuroprotective effects of the assumed medications, or to the frequent comorbidity of CH with neuropsychiatric disorders or if they are a genuine neural signature of CH and/or cCH condition.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yueyun Lan ◽  
Sheng Yi ◽  
Mengting Li ◽  
Jinqiu Wang ◽  
Qi Yang ◽  
...  

Christianson syndrome (CS) is an X-linked neurodevelopmental syndrome characterized by microcephaly, epilepsy, ataxia, and severe generalized developmental delay. Pathogenic mutations in the SLC9A6 gene, which encodes the Na+/H+ exchanger protein member 6 (NHE6), are associated with CS and autism spectrum disorder in males. In this study, whole exome sequencing (WES) and Sanger sequencing revealed a novel de novo frameshift variant c.1548_1549insT of SLC9A6 in a 14-month-old boy with early-onset seizures. According to The American College of Medical Genetics and Genomics (ACMG)/the Association for Molecular Pathology (AMP) guidelines, the variant was classified as pathogenic. The proband presented with several core symptoms of typical epilepsy, including microcephaly, motor delay, distal muscle weakness, micrognathia, occasional unprovoked laughter, swallowing and speech difficulties. Electroencephalography (EEG) showed spikes-slow waves in frontal pole, frontal, anterior temporal and frontal midline point areas. Gesell development schedules (GDS) indicated generalized developmental delay. We also summarized all the reported variants and analyzed the correlation of genotype and phenotype of CS. Our study extends the mutation spectrum of the SLC9A6 gene, and it might imply that the phenotypes of CS are not correlated with SLC9A6 genotypes.


2021 ◽  
pp. 097275312110598
Author(s):  
Sushma Rao Poleneni ◽  
Lakshmi Durga Jakka ◽  
Mrudula Chandrupatla ◽  
L. Vinodini ◽  
K. Ariyanachi

Background: The corpus callosum (CC) is a connecting bridge between two cerebral hemispheres and helps in interhemispheric integration of information. Purpose: The primary objective of the study is to explain the topographical position of CC in relation to the brain in the South Indian population, contributing to the reference values of measurements of CC, which helps in planning surgical interventions. Also, the reference values help in cross-referencing with other populations and ethnic group. Methods and Material: In the study, 40 formalin fixed, full brain specimens were cut in midsagittal plane and CC was measured along with its relation to the brain. The major diameters considered were longitudinal dimension of corpus callosum (LC), distance of CC from frontal pole to genu (AS), distance of CC occipital pole to splenium (PS), and longitudinal dimension of brain (LB) from frontal pole to occipital pole. Statistical Analysis Used: The statistical analysis was carried with the mean, standard deviation, 95% CI, and the range measured for each measurement. The Pearson coefficient was evaluated between dimensions of brain and CC. Multivariate linear regression analysis was done to correlate between LB as a dependent variable, and LC, vertical dimension of brain (CD), and PS as independent variables. Results: Pearson’s ratio showed a positive correlation between LB and PS (0.61), and also between LB and LC (0.59). The ratio of LC/LB was 0.45 and LC/CD was 0.69, which are stable in all brains studied. Conclusions: The study concludes that CC maintains a stable proportion with its parts (genu, rostrum, body, and splenium) and with the horizontal dimension of the brain. Further, measured values help in cross-referencing with other population.


2021 ◽  
Author(s):  
Andrzej Sokołowski ◽  
Monika Folkierska-Żukowska ◽  
Katarzyna Jednoróg ◽  
Marek Wypych ◽  
Wojciech Ł. Dragan

AbstractStress may impact the ability to effectively regulate emotions. To study the impact of stressful experiences in early and recent life on emotion regulation, we examined the relationship between early life stress, recent stress, and brain activation during cognitive reappraisal. We investigated two regulation goals: the decrease and increase of emotional response to both negative and positive stimuli. Furthermore, two models of stress consequences were examined: the cumulative and match/mismatch models. A total of 83 participants (Mage = 21.66) took part in the study. There was an interaction between cumulative stress and stimuli valence in the cuneus, superior lateral occipital cortex, superior parietal lobule, supramarginal gyrus extending to superior temporal gyrus, and precentral gyrus extending to supplementary motor area. Interaction between mismatched stress index and stimuli valence was found in the left hippocampus, left insula extending to the orbitofrontal cortex and amygdala, and in a cluster including the anterior cingulate cortex, superior frontal gyrus, and frontal pole. Furthermore, there were differences between the effects of cumulative and mismatched stress indices on brain activation during reappraisal of positive but not negative stimuli. Results indicate that cumulative stress and match/mismatch approaches are both useful for explaining brain activation during reappraisal. This finding is important for our understanding of the multifaceted impact of stress on emotion regulation.


2021 ◽  
Author(s):  
María Goñi ◽  
Neil Basu ◽  
Alison D Murray ◽  
Gordon D Waiter

Background: Fatigue is a common and burdensome symptom in Rheumatoid Arthritis (RA), yet is poorly understood. Currently, clinicians rely solely on fatigue questionnaires, which are inherently subjective measures. For the effective development of future therapies and stratification, it is of vital importance to identify biomarkers of fatigue. In this study, we identify brain differences between RA patients who improved and did not improve their levels of fatigue, and we compared the performance of different classifiers to distinguish between these samples at baseline. Methods: Fifty-four fatigued RA patients underwent a magnetic resonance (MR) scan at baseline and 6 months later. At 6 months we identified those whose fatigue levels improved and those for whom it did not. More than 900 brain features across three data sets were assessed as potential predictors of fatigue improvement. These data sets included clinical, structural MRI (sMRI) and diffusion tensor imaging (DTI) data. A genetic algorithm was used for feature selection. Three classifiers were employed in the discrimination of improvers and non-improvers of fatigue: a Least Square Linear Discriminant (LSLD), a linear Support Vector Machine (SVM) and a SVM with Radial Basis Function kernel. Results: The highest accuracy (67.9%) was achieved with the sMRI set, followed by the DTI set (63.8%), whereas classification performance using clinical features was at the chance level. The mean curvature of the left superior temporal sulcus was most strongly selected during the feature selection step, followed by the surface are of the right frontal pole and the surface area of the left banks of the superior temporal sulcus. Conclusions: The results presented in this study evidence a superiority of brain metrics over clinical metrics in predicting fatigue changes. Further exploration of these methods may enable clinicians to triage patients towards the most appropriate fatigue alleviating therapies.


2021 ◽  
Author(s):  
Laura S. van Velzen ◽  
Maria R. Dauvermann ◽  
Lejla Colic ◽  
Luca M. Villa ◽  
Hannah S. Savage ◽  
...  

AbstractObjectiveIdentifying brain differences associated with suicidal thoughts and behaviors (STBs) in young people is critical to understanding their development and generating effective approaches to early intervention and prevention. The ENIGMA Suicidal Thoughts and Behaviours (ENIGMA-STB) consortium analyzed neuroimaging data harmonized across sites to examine brain morphology associated with STBs in youth.MethodsFirst, we examined associations among regional brain structure and STBs, which were assessed in six samples of youth with mood disorders, using the Columbia Suicide Severity Rating Scale (C-SSRS; N=577). Second, we combined this sample with a larger sample (total 21 sites) in which STBs were assessed using various instruments. MRI metrics were compared among healthy controls without STBs (HC; N=688), clinical controls without STBs (CC; N=648), and young people with psychiatric diagnoses and current suicidal ideation (N=406). In separate analyses, MRI metrics were compared among HCs (N=335), CCs (N=768), and suicide attempters (N=254).ResultsIn the homogeneous C-SSRS sample, surface area of the frontal pole was lower in young people with mood disorders and history of actual suicide attempts (N=163) than those without (N=394; FDR-p<.001; Cohen’s d=.334). When expanding to more clinically heterogeneous samples, we also found lower surface area of the frontal pole in those with a history of suicide attempts (Cohen’s d=.22).ConclusionsLower frontal pole surface area may represent a vulnerability for a suicide attempt; however, more research is needed to understand the nature of its relationship to suicide risk.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Brian Dean ◽  
Elizabeth Scarr

AbstractPostmortem and neuroimaging studies show low levels of cortical muscarinic M1 receptors (CHRM1) in patients with schizophrenia which is significant because CHRM signalling has been shown to change levels of gene expression and cortical gene expression is altered in schizophrenia. We decided to identify CHRM1-mediated changes in cortical gene expression by measuring levels of RNA in the cortex of the Chrm1−/− mouse (n = 10), where there would be no signalling by that receptor, and in wild type mouse (n = 10) using the Affymetrix Mouse Exon 1.0 ST Array. We detected RNA for 15,501 annotated genes and noncoding RNA of which 1,467 RNAs were higher and 229 RNAs lower in the cortex of the Chrm1−/− mouse. Pathways and proteins affected by the changes in cortical gene expression in the Chrm1−/− are linked to the molecular pathology of schizophrenia. Our human cortical gene expression data showed 47 genes had altered expression in Chrm1−/− mouse and the frontal pole from patients with schizophrenia with the change in expression of 44 genes being in opposite directions. In addition, genes with altered levels of expression in the Chrm1−/− mouse have been shown to affect amyloid precursor protein processing which is associated with the pathophysiology of Alzheimer’s disease, and 69 genes with altered expression in the Chrm1−/− mouse are risk genes associated with human cognitive ability. Our findings argue CHRM1-mediated changes in gene expression are relevant to the pathophysiologies of schizophrenia and Alzheimer’s disease and the maintenance of cognitive ability in humans.


2021 ◽  
pp. 026988112110446
Author(s):  
Peter van Ruitenbeek ◽  
Conny WEM Quaedflieg ◽  
Dennis Hernaus ◽  
Bart Hartogsveld ◽  
Tom Smeets

Background: Acute stress is thought to reduce goal-directed behaviour, an effect purportedly associated with stress-induced release of catecholamines. In contrast, experimentally increased systemic catecholamine levels have been shown to increase goal-directed behaviour. Whether experimentally increased catecholamine function can modulate stress-induced reductions in goal-directed behaviour and its neural substrates, is currently unknown. Aim: To assess whether and how experimentally induced increases in dopamine and noradrenaline contribute to the acute stress effects on goal-directed behaviour and associated brain activation. Methods: One hundred participants underwent a stress induction protocol (Maastricht acute stress test; MAST) or a control procedure and received methylphenidate (MPH) (40 mg, oral) or placebo according to a 2 × 2 between-subjects design. In a well-established instrumental learning paradigm, participants learnt stimulus–response–outcome associations, after which rewards were selectively devalued. Participants’ brain activation and associated goal-directed behaviour were assessed in a magnetic resonance imaging scanner at peak cortisol/MPH concentrations. Results: The MAST and MPH increased physiological measures of stress (salivary cortisol and blood pressure), but only MAST increased subjective measures of stress. MPH modulated stress effects on activation of brain areas associated with goal-directed behaviour, including insula, putamen, amygdala, medial prefrontal cortex, frontal pole and orbitofrontal cortex. However, MPH did not modulate the tendency of stress to induce a reduction in goal-directed behaviour. Conclusion: Our neuroimaging data suggest that MPH-induced increases in dopamine and noradrenaline reverse stress-induced changes in key brain regions associated with goal-directed behaviour, while behavioural effects were absent. These effects may be relevant for preventing stress-induced maladaptive behaviour like in addiction or binge eating disorder.


Sign in / Sign up

Export Citation Format

Share Document