Cortical thickness of the rostral anterior cingulate gyrus is associated with frailty in patients with end-stage renal disease undergoing hemodialysis in Korea: a cross-sectional study

BACKGROUND

Frailty is defined as a condition of being weak and delicate, and it represents a state of high vulnerability to adverse health outcomes. Recent studies have suggested that the cingulate gyrus is associated with frailty in the elderly population. However, few imaging studies have explored the relationship between frailty and the cingulate gyrus in patients with end-stage renal disease (ESRD) undergoing hemodialysis.

METHODS

Eighteen right-handed patients with ESRD undergoing hemodialysis were enrolled in the study. We used the FreeSurfer software package to estimate the cortical thickness of the regions of interest, including the rostral anterior, caudal anterior, isthmus, and posterior cingulate gyri. The Beck Depression Inventory, Beck Anxiety Inventory, and laboratory tests were also conducted.

RESULTS

The cortical thickness of the right rostral anterior cingulate gyrus (ACG) was significantly correlated with the Fried frailty index, age, and creatinine level. Multiple regression analysis indicated that the cortical thickness of the right rostral ACG was associated with frailty after controlling for age and creatinine level.

CONCLUSION

Our results indicate that the cortical thickness of the rostral ACG may be associated with frailty in patients with ESRD on hemodialysis and that the rostral ACG may play a role in the frailty mechanism of this population.

Sex-specific association between prenatal androgenization (second-to-fourth digit length ratio) and frontal brain volumes in adolescents

Prenatal androgenization associates sex-dependently with behavior and mental health in adolescence and adulthood, including risk-taking, emotionality, substance use, and depression. However, still little is known on how it affects underlying neural correlates, like frontal brain control regions. Thus, we tested whether prenatal androgen load is sex-dependently related to frontal cortex volumes in a sex-balanced adolescent sample. In a cross-sectional magnetic resonance imaging study, we examined 61 adolescents (28 males, 33 females; aged 14 or 16 years) and analyzed associations of frontal brain region volumes with the second-to-fourth digit length ratio (2D:4D), an established marker for prenatal androgenization, using voxel-based morphometry in a region-of-interest approach. Lower 2D:4D (indicative of higher prenatal androgen load) correlated significantly with smaller volumes of the right anterior cingulate cortex (r-ACC; β = 0.45) in male adolescents and with larger volumes of the left inferior frontal gyrus orbital part (l-IFGorb; β = - 0.38) in female adolescents. The regression slopes of 2D:4D on the r-ACC also differed significantly between males and females. The study provides novel evidence that prenatal androgenization may influence the development of the frontal brain in a sex- and frontal brain region-specific manner. These effects might contribute to the well-known sex differences in risk-taking, emotionality, substance use, and depression. Future research is needed to elucidate the role of prenatal androgenization within the biopsychosocial model.

EEG source derived salience network coupling supports real-world attention switching

While the brain mechanisms underlying selective attention have been studied in great detail in controlled laboratory settings, it is less clear how these processes function in the context of a real-world self-paced task. Here, we investigated engagement on a real-world computerized task equivalent to a standard academic test that consisted of solving high-school level problems in a self-paced manner. In this task, we used EEG-source derived estimates of effective coupling between brain sources to characterize the neural mechanisms underlying switches of sustained attention from the attentive on-task state to the distracted off-task state. Specifically, since the salience network has been implicated in sustained attention and attention switching, we conducted a hypothesis-driven analysis of effective coupling between the core nodes of the salience network, the anterior insula (AI) and the anterior cingulate cortex (ACC). As per our hypothesis, we found an increase in AI - > ACC effective coupling that occurs during the transitions of attention from on-task focused to off-task distracted state. This research may inform the development of future neural function-targeted brain-computer interfaces to enhance sustained attention.

The dysregulation of top-down control in individuals with high test anxiety: A resting state fMRI study

BACKGROUND

Individuals with high test anxiety (HTA) have deficits in attentional control and in stress responses when faced with tests. However, little is known about the underlying neural mechanism. Anterior cingulate cortex (ACC) is involved in both attention and emotion networks, therefore this study examined the neural functional dysregulation in test anxiety from the perspective of functional connectivity (FC) using bilateral ACC as the regions of interest.

METHODS

Fifty-one participants were divided into HTA (n = 23) and low test anxiety (LTA, n = 28) group according to their Test Anxiety Scale (TAS) scores. Brain imaging data in resting, preparing, and recovering phases of a modified social evaluative threat task were collected, and emotional changes were assessed.

RESULTS

Compared with the LTA group, the HTA group exhibited significantly lower FCs between the ACC and superior frontal gyrus (SFG) in all 3 phases, significantly lower FCs between the ACC and inferior parietal gyrus (IPG), and significantly higher FCs between the ACC superior temporal gyrus (STG) in the preparing phase. Moreover, in the HTA group, the resting state IPG-ACC FC was associated with their TAS score, the preparing state STG-ACC FC was associated with the increased anxiety.

CONCLUSIONS

Individuals with HTA have general prefrontal control deficits. When facing a test, they tend to recruit more resources to deal with high emotional interference. The dysregulated control of the ACC by the frontal-parietal network may underlie the pathophysiology of test anxiety.

Brain structural correlates of upward social mobility in ethnic minority individuals

PURPOSE

Perigenual anterior cingulate cortex (pACC) is a neural convergence site for social stress-related risk factors for mental health, including ethnic minority status. Current social status, a strong predictor of mental and somatic health, has been related to gray matter volume in this region, but the effects of social mobility over the lifespan are unknown and may differ in minorities. Recent studies suggest a diminished health return of upward social mobility for ethnic minority individuals, potentially due to sustained stress-associated experiences and subsequent activation of the neural stress response system.

METHODS

To address this issue, we studied an ethnic minority sample with strong upward social mobility. In a cross-sectional design, we examined 64 young adult native German and 76 ethnic minority individuals with comparable sociodemographic attributes using whole-brain structural magnetic resonance imaging.

RESULTS

Results showed a significant group-dependent interaction between perceived upward social mobility and pACC gray matter volume, with a significant negative association in the ethnic minority individuals. Post-hoc analysis showed a significant mediation of the relationship between perceived upward social mobility and pACC volume by perceived chronic stress, a variable that was significantly correlated with perceived discrimination in our ethnic minority group.

CONCLUSION

Our findings extend prior work by pointing to a biological signature of the "allostatic costs" of socioeconomic attainment in socially disadvantaged upwardly mobile individuals in a key neural node implicated in the regulation of stress and negative affect.

A functional magnetic resonance imaging investigation of the autonomous sensory meridian response

BACKGROUND

Autonomous Sensory Meridian Response (ASMR) is a sensory-emotional experience in which specific stimuli (ASMR "triggers") elicit tingling sensations on the scalp, neck, and shoulders; these sensations are accompanied by a positive affective state. In the current research, functional magnetic resonance imaging (fMRI) was used in order to delineate the neural substrates of these responses.

METHODS

A total of 17 individuals with ASMR and 17 age- and sex-matched control participants underwent fMRI scanning while watching six 4-minute videos. Three of the videos were designed to elicit ASMR tingling and three videos were not.

RESULTS

The results demonstrated that ASMR videos have a distinct effect on the neural activity of individuals with ASMR. The contrast of ASMR participants' responses to ASMR videos showed greater activity in the cingulate gyrus as well as in cortical regions related to audition, movement, and vision. This activity was not observed in control participants. The contrast of ASMR and control participants' responses to ASMR-eliciting videos detected greater activity in right cingulate gyrus, right paracentral lobule, and bilateral thalamus in ASMR participants; control participants showed greater activity in the lingula and culmen of the cerebellum.

CONCLUSIONS

Together, these results highlight the fact that ASMR videos elicit activity in brain areas related to sensation, emotion, and attention in individuals with ASMR, but not in matched control participants.

Correlations between changes in the hypothalamic-pituitary-adrenal axis and neurochemistry of the anterior cingulate gyrus in postpartum depression

BACKGROUND

This study aimed to investigate associations between indicators of hypothalamic-pituitary-adrenal axis (HPA) functioning and metabolite levels in the anterior cingulate gyrus (ACG) of women with postpartum depression (PPD).

METHODS

The sample (mean age = 28.5 ± 4.6 years) consisted of 20 women with PPD and 19 postpartum euthymic (PPE) women. Brain metabolites were quantified by proton magnetic resonance spectroscopy (¹H-MRS). Salivary cortisol samples were collected upon awakening and 30 min and 12 h later, at 20.6 ± 6.6 (PPD) and 23.0 ± 7.4 (PPE) weeks after childbirth.

RESULTS

There were no significant differences between groups in respect to metabolite levels in the ACG. Compared with PPE, PPD women had less diurnal variation (DVr%). In the PPD group, positive correlations were found between DVr% and myo-inositol (mI/Cr) levels, and between cortisol awakening response (CARi%) and glutamate + glutamine (Glx/Cr) levels. The correlation between CARi% and Glx/Cr remained significant even after controlling for the interval, in weeks, from birth and MR spectroscopy and to hormonal data collection, and the use of contraceptives.

LIMITATIONS

The limitations of the study include the small sample size and the use of oral contraceptives by around half of the sample.

CONCLUSIONS

In the remote postpartum period (mean 21.8 ± 6.9 weeks) and in the presence of depressive episodes, the decreased responsiveness of the HPA axis after awakening and a smaller decrease in cortisol levels over the day were associated with lower levels of metabolites in the ACG. These results may contribute to the development of biological models to explain the etiology of PPD.

Correlation between extreme fear and focal cortical dysplasia in anterior cingulate gyrus: Evidence from a surgical case of refractory epilepsy

Localizing the semiology of ictal fear and seizure onset in epilepsy patients is commonly challenging due to limited value of routine electroencephalography (EEG) and very few surgical attempts. Here we reported a case of refractory epilepsy characterized by aura of extreme fear and hypermotor seizures, in which the left (dominant hemisphere) anterior cingulate gyrus (ACG) was determined to be the epileptogenic zone (EZ) through multiple modalities of presurgical evaluation including analysis of high frequency oscillation on intracranial EEG. Tailored resection of EZ was thus performed and pathological examination revealed focal cortical dysplasia (FCD) type IIb. The patient has been seizure free during an 18-month follow-up. The report has provided novel anatomical, electrophysiological and surgical evidences suggesting the critical role of ACG in ictal fear and possibility of surgical management of fear-manifesting refractory epilepsy.

Glutamatergic and neural dysfunction in postpartum depression using magnetic resonance spectroscopy

Although postpartum depression (PPD) is a prevalent subtype of major depressive disorder, neuroimaging studies on PPD are rare, particularly those identifying neurochemical abnormalities obtained by proton magnetic resonance spectroscopy (¹H-MRS). The dorsolateral prefrontal (DLPF) and the anterior cingulate gyrus (ACG) are part of the neural pathways involved in executive functions and emotional processing, and both structures have been implicated in the neurobiology of depressive disorders. This study aimed to evaluate brain metabolites abnormalities in women with PPD compared with healthy postpartum (HP) women. Thirty-six PPD (34 without antidepressants) and 25 HP women underwent a ¹H-MRS acquired on a 3-T MRI system, with the volume of interest positioned in ACG and DLPF. An ANCOVA was conducted with age, postpartum time, and contraceptive type as covariates. PPD group presented significantly lower Glutamate+Glutamine (Glx, -0.95mM) and N-acetylaspartate+N-acetylaspartylglutamate (NAA, -0.60mM) values in DLPF. There were no significant differences between groups in ACG, but we found a significant increase of Glutamate (Glu, 2.18mM) and Glx (1.84mM) in participants using progestogen-only contraceptives. These findings suggest glutamatergic dysfunction and neuronal damage in the DLPF of PPD patients, similarly to other subtypes of depressive disorders. Progestogens seem to interfere in the neurochemistry of ACG.

Pica in a Child with Anterior Cingulate Gyrus Oligodendroglioma: Case Report

The anterior cingulate gyrus (ACG) is a continued focus of research as its exact role in brain function and vast connections with other anatomical locations is not fully understood. A review of the literature illustrates the role the ACG likely plays in cognitive and emotional processing, as well as a modulating role in motor function and goal-oriented behaviors. While lesions of the cingulate gyrus are rare, each new case broadens our understanding of its role in cognitive neuroscience and higher order processing. The authors present the case of an 8-year-old boy with a 1-month history of staring spells, agitated personality, and hyperphagia notable for the consumption of paper, who was found to have a 3-cm tumor in the left ACG. Following surgical resection of the tumor, his aggressive behavior and pica were ameliorated and the patient made an uneventful recovery, with no evidence of recurrence over the last 6 years since surgical resection. Here we discuss a unique behavioral presentation of pica, along with a review of the current literature, to illustrate functions of the ACG relevant to the location of the lesion.

Ketamine-dependent neuronal activation in healthy volunteers

Over the last years, a number of studies have been conducted to clarify the neurobiological correlates of ketamine application. However, comprehensive information regarding the influence of ketamine on cortical activity is still lacking. Using resting-state functional MRI and integrating pharmacokinetic information, a double-blind, randomized, placebo-controlled, crossover study was performed to determine the effects of ketamine on neuronal activation. During a 55 min resting-state fMRI scan, esketamine (Ketanest S^®) was administered intravenously to 35 healthy volunteers. Neural activation as indicated by the BOLD signal using the pharmacokinetic curve of ketamine plasma levels as a regressor was computed. Compared with placebo, ketamine-dependent increases of neural activation were observed in the midcingulate cortex, the dorsal part of the anterior cingulate cortex, the insula bilaterally, and the thalamus (t values ranging between 5.95-9.78, p < 0.05; FWE-corrected). A significant decrease of neural activation in the ketamine condition compared to placebo was found in a cluster within the subgenual/subcallosal part of the anterior cingulate cortex, the orbitofrontal cortex and the gyrus rectus (t = 7.81, p < 0.05, FWE-corrected). Using an approach combining pharmacological and fMRI data, important information about the neurobiological correlates of the clinical antidepressant effects of ketamine could be revealed.

Docosahexaenoic acid biostatus is associated with event-related functional connectivity in cortical attention networks of typically developing children

OBJECTIVE

Although extant preclinical evidence suggests that the long-chain omega-3 fatty acid docosahexaenoic acid (DHA) is important for neurodevelopment, little is known about its role in human cortical structural and functional maturation. In the present cross-sectional study, we investigated the relationship between DHA biostatus and functional connectivity in cortical attention networks of typically developing children.

METHODS

Male children (aged 8-10 years, n = 36) were divided into 'low-DHA' (n = 18) and 'high-DHA' (n = 18) biostatus groups by a median split of erythrocyte DHA levels. Event-related functional connectivity during the performance of a sustained attention task (identical pairs continuous performance task (CPT-IP)) was conducted using functional magnetic resonance imaging. A voxelwise approach used the anterior cingulate cortex (ACC) as the seed-region.

RESULTS

Erythrocyte DHA composition in the low-DHA group (2.6 ± 0.9%) was significantly lower than the high-DHA group (4.1 ± 1.1%, P ≤ 0.0001). Fish intake frequency was greater in the high-DHA group (P = 0.003) and was positively correlated with DHA levels among all subjects. The low-DHA group exhibited reduced functional connectivity between the ACC and the ventrolateral prefrontal cortex, insula, precuneus, superior parietal lobule, middle occipital gyrus, inferior temporal gyrus, and lingual gyrus compared with the high-DHA group (P < 0.05; corrected). The low-DHA group did not exhibit greater ACC functional connectivity with any region compared with the high-DHA group. On the CPT-IP task, the low-DHA group had slower reaction time (P = 0.03) which was inversely correlated with erythrocyte DHA among all subjects.

DISCUSSION

These data suggest that low-DHA biostatus is associated with reduced event-related functional connectivity in cortical attention networks of typically developing children.

Correlations of inflammatory gene pathways, corticolimbic functional activities, and aggression in pediatric bipolar disorder: a preliminary study

The mechanisms underlying aggression in adolescents with bipolar disorder have been poorly understood. The present study has investigated the associations among TNF gene expressions, functional brain activations under the frustrative non-reward task, and aggression in adolescents with bipolar disorder. Baseline gene expressions and aggressive tendencies were measured with the RNA-sequencing and Brief Rating of Aggression by Children and Adolescents (BRACHA), respectively. Our results show that activity levels of left subgenual anterior cingulate gyrus (ACG), right amygdala, left Brodmann area 10 (orbitofrontal cortex), and right thalamus were inversely correlated with BRACHA scores and were activated with frustrative non-reward during the affective Posner Task. In addition, 11 TNF related gene expressions were significantly correlated with activation of amygdala or ACG during the affective Posner Task. Three TNF gene expressions were inversely correlated with BRACHA score while one TNF gene (TNFAIP3) expression was positively correlated with BRACHA score. Therefore, TNF-related inflammatory cytokine genes may play a role in neural activity associated with frustrative non-reward and aggressive behaviors in pediatric bipolar disorder.

Neurodevelopmental changes in the responsiveness of systems involved in top down attention and emotional responding

In this study, we aimed to investigate age related changes in systems implicated in top down attention and the implications of this for amygdala responses to emotional distracters. Fifty-one healthy subjects including 18 children (aged 10-14), 15 adolescents (aged 14-18), and 18 young adults (aged 18-25) completed the affective Stroop paradigm while undergoing functional MRI. While achieving comparable behavioral performance, children, relative to adolescents and adults, showed increased activation in areas including anterior cingulate gyrus and precentral gyrus in task relative to view trials. In addition, children showed increased activation within the amygdala and fusiform gyrus in response to emotional stimuli. Notably, the group difference within the amygdala was particularly pronounced during task trials. Also children showed increased connectivity between amygdala and superior frontal gyrus and bilateral postcentral gyrii in response to negative task trials. These data are consistent with previous work indicating less consolidated functional integrity in regions implicated in top down attention in children relative to older participants and extend this work by indicating that this less consolidated functional integrity leads to reduced automatic emotion regulation as a function of top down attention. Given that reduced automatic emotion regulation as a function of top down attention is considered a risk factor for the development of anxiety disorders, these data may contribute to an understanding of the increased risk for the development of these disorders at this age.

Depressive symptoms and neuroanatomical structures in community-dwelling women: A combined voxel-based morphometry and diffusion tensor imaging study with tract-based spatial statistics

Depressive symptoms, even at a subclinical level, have been associated with structural brain abnormalities. However, previous studies have used regions of interest or small sample sizes, limiting the ability to generalize the results. In this study, we examined neuroanatomical structures of both gray matter and white matter associated with depressive symptoms across the whole brain in a large sample. A total of 810 community-dwelling adult participants underwent measurement of depressive symptoms with the Center for Epidemiologic Studies Depression Scale (CES-D). The participants were not demented and had no neurological or psychiatric history. To examine the gray and white matter volume, we used structural MRI scans and voxel-based morphometry (VBM); to examine the white matter integrity, we used diffusion tensor imaging with tract-based spatial statistics (TBSS). In female participants, VBM revealed a negative correlation between bilateral anterior cingulate gray matter volume and the CES-D score. TBSS showed a CES-D-related decrease in fractional anisotropy and increase in radial and mean diffusivity in several white matter regions, including the right anterior cingulum. In male participants, there was no significant correlation between gray or white matter volume or white matter integrity and the CES-D score. Our results indicate that the reduction in gray matter volume and differences in white matter integrity in specific brain regions, including the anterior cingulate, are associated with depressive symptoms in women.

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We studied neuroanatomical structures associated with subclinical depression.

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The analysis was performed across the whole brain in a large sample.

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Anterior cingulate gray matter volume reduction was revealed by VBM.

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Broad white matter integrity differences were revealed by DTI with TBSS.

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Both changes were seen only in females but not in males.