Aberrant functional connectivity in anterior cingulate gyrus subregions in migraine without aura patients.

Background: The anterior cingulate gyrus (ACG) is an important regulatory region for pain-related information. However, the ACG is composed of subregions with different functions. The mechanisms underlying the brain networks of different subregions of the ACG in patients with migraine without aura (MwoA) are currently unclear. Methods: In the current study, resting-state functional magnetic resonance imaging (rsfMRI) and functional connectivity (FC) were used to investigate the functional characteristics of ACG subregions in MwoA patients. The study included 17 healthy volunteers and 28 MwoA patients. The FC calculation was based on rsfMRI data from a 3 T MRI scanner. The brain networks of the ACG subregions were compared using a general linear model to see if there were any differences between the two groups. Spearman correlation analysis was used to examine the correlation between FC values in abnormal brain regions and clinical variables. Results: Compared with healthy subjects, MwoA patients showed decreased FC between left subgenual ACG and left middle cingulate gyrus and right middle temporal gyrus. Meanwhile, MwoA patients also showed increased FC between pregenual ACG and right angular gyrus and increased FC between right pregenual ACG and right superior occipital gyrus. The FC values between pregenual ACG and right superior occipital gyrus were significantly positively correlated with the visual analogue scale. Conclusion: Disturbances of FC between ACG subregions and default model network and visual cortex may play a key role in neuropathological features, perception and affection of MwoA. The current study provides further insights into the complex scenario of MwoA mechanisms.

Clavulanic Acid Decreases Cocaine Cue Reactivity in Addiction-Related Brain Areas, a Randomized fMRI Pilot Study.

Background: Preclinical studies show that clavulanic acid (CLAV) inhibits cocaine self-administration. This study investigates the effect of CLAV on regions of brain activation in response to cocaine cues during functional magnetic resonance imaging (fMRI) in participants with cocaine use disorder (CUD). Methods: A double-masked, placebo-controlled clinical trial with thirteen individuals with severe CUD who were randomized to treatment with CLAV (N = 10, 9 completers) 500 mg/day or matched placebo (PBO) (N = 3) for 3 days. fMRI was used to assess brain reactivity to 18 alternating six-second video clips of cocaine or neutral scenes. In this paradigm, participants were exposed to three different stimulus conditions: NEUTRAL, WATCH (passive watching), and DOWN (actively inhibiting craving while watching). Results: Participants who received CLAV demonstrated a significant reduction in brain activity in the anterior cingulate gyrus (p = 0.009) and the caudate (p = 0.018) in response to DOWN cocaine cues. There was a trend toward lessened cue reactivity in other regions implicated in CUD. Conclusion: CLAV reduced the response of the brain regions associated with motivation and emotional response during the DOWN condition compared to PBO, suggesting CLAV may strengthen voluntary efforts to avoid cocaine use. This pilot data supports the use of CLAV for CUD. (Trial registered in ClinicalTrials.gov NCT04411914).

Predictive factors of post-operative apathy in patients with diffuse frontal gliomas undergoing awake brain mapping.

Patients with diffuse frontal gliomas often present with post-operative apathy after tumour removal. However, the association between apathy and tumour removal of gliomas from the frontal lobe remains unknown. This study aimed to investigate the factors influencing post-operative apathy after tumour removal in patients with diffuse frontal gliomas. We compared the demographics and clinical characteristics of patients with and without post-operative apathy in a cohort of 54 patients who underwent awake brain mapping for frontal gliomas. The frequency of clinical parameters such as left-sided involvement, high-grade tumour types (WHO grades III, IV), main tumour location in the anterior cingulate gyrus (ACC) and/or dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) was significantly greater in the apathetic group compared to the non-apathetic group. The apathetic group scored significantly lower on neuropsychological assessments such as the Letter Fluency Test among the Word Fluency Tests than the non-pathetic group (p = .000). Moreover, the scores of Parts 3, and 3-1 of the Stroop test were significantly lower in the apathetic group than those in the non-apathetic group (p = .023, .027, respectively). Multivariate model analysis revealed that the appearance of post-operative apathy was significantly related to side of the of lesion [left vs. right, hazard ratio (HR) = 8.00, 95% confidence interval (CI) = 1.36-46.96, p = .021], location of the main tumour in the frontal lobe (ACC/DLPFC/OFC vs. others, HR = 7.99, 95% CI = 2.16-29.59, p = .002), and the Letter Fluency Test (HR = .37, 95% CI = .15-.90, p = .028). Post-operative apathy is significantly associated with ACC and/or DLPFC and OFC in the left hemisphere of diffuse frontal gliomas. Apathy in frontal gliomas is correlated with a decline in the Letter Fluency Test scores. Therefore, this instrument is a potential predictor of post-operative apathy in patients with diffuse frontal gliomas undergoing awake brain mapping.

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.

Toward the unknown: consciousness and pain.

Studies of consciousness are hindered by the complexity of the brain, but it is possible to study the consciousness of a sensation, namely pain. Three systems are necessary to experience pain: the somatosensory system conveys information about an injury to the thalamus where an awareness of the injury but not the painfulness emerges. The thalamus distributes the information to the affective system, which modulates the intensity of the pain, and to the cognitive system that imparts attention to the pain. Imaging of patients in pain and those experiencing placebo and hypnosis-induced analgesia shows that two essential cortical circuits for pain and attention are located within the anterior cingulate cortex. The circuits are activated when a high-frequency input results in the development of a long-term potentiation (LTP) at synapses on the apical dendrites of pyramidal neurons. The LTP acts via α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors, and an anterior cingulate cortex-specific type-1 adenylate cyclase is necessary for both the LTP and the pain. The apical dendrites form an extensive network such that the input from serious injuries results in the emergence of a local field potential. Using mouse models, I propose experiments designed to test the hypothesis that the local field potential is necessary and sufficient for the consciousness of pain.

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; ß = 0.45) in male adolescents and with larger volumes of the left inferior frontal gyrus orbital part (l-IFGorb; ß = - 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.

Fatigue in Cirrhosis.

Fatigue is a common symptom in patients with liver disease and has a significant impact on the health-related quality of life (HR-QoL). Its pathogenesis is poorly understood and is considered multifactorial. The liver is central in the pathogenesis of fatigue because it uniquely regulates much of the production, storage, and release of substrate for energy generation. Also, the liver "cross-talks" with the key organs that are responsible for this symptom complex-gut, skeletal muscle, and brain. Fatigue can have both peripheral (i.e., neuromuscular) and central (i.e., resulting from changes in neurotransmission within the brain) components. The treatment strategies for the management of fatigue are behavioral changes and pharmacotherapy, along with dietetic intervention and exercise. However, there is no consensus on management strategies for fatigue in patients with liver disease. This article gives an overview of fatigue as a concept, its pathophysiology, measures to evaluate fatigue in patients with liver disease, the impact of fatigue on chronic liver disease, assessment of fatigue in an appropriate clinical setting, and various interventions to manage fatigue.

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.

Effects of transcutaneous auricular vagus nerve stimulation on brain functional connectivity of medial prefrontal cortex in patients with primary insomnia.

As a representative of acupuncture and nonpharmaceutical therapy, auricular acupuncture has been widely for the treatment of insomnia. Transcutaneous auricular vagus nerve stimulation (taVNS) is a combination of auricular point stimulation and vagus nerve stimulation. It can not only treat primary insomnia effectively, but also is noninvasive, painless, portable and economical. The medial prefrontal cortex (mPFC) is a core region of default mode network (DMN), which is important for maintenance of sleep. However, the mechanism of taVNS in alleviating primary insomnia (PI) remains to be clarified. In this study, we found that taVNS could not only effectively reduce the score of Pittsburgh Sleep Quality Index, but also decreased functional connection (FC) between the left mPFC and bilateral dorsal anterior cingulate gyrus as well as FC between the right mPFC and the occipital cortex in patients with PI. Furthermore, the decrease in FC was positively correlated with the decline of sleep index score. Therefore, we proposed that treatment with taVNS can improve sleep quality and prolong sleep duration in patients with PI by reducing FC within DMN, FC between DMN and salience network, as well as FC between DMN and the occipital cortex. This may be one of mechanisms of taVNS in treating PI.

Determinants of Schizophrenia Endophenotypes Based on Neuroimaging and Biochemical Parameters.

Despite extensive research, there is no convincing evidence of a reliable diagnostic biomarker for schizophrenia beyond clinical observation. Disorders of glutamatergic neurotransmission associated with N-methyl-D-aspartate (NMDA) receptor insufficiency, neuroinflammation, and redox dysregulation are the principal common mechanism linking changes in the periphery with the brain, ultimately contributing to the emergence of negative symptoms of schizophrenia that underlie differential diagnosis. The aim of the study was to evaluate the influence of these systems via peripheral and cerebral biochemical indices in relation to the patient's clinical condition. Using neuroimaging diagnostics, we were able to define endophenotypes of schizophrenia based on objective laboratory data that form the basis of a personalized approach to diagnosis and treatment. The two distinguished endophenotypes differed in terms of the quality of life, specific schizophrenia symptoms, and glutamatergic neurotransmission metabolites in the anterior cingulate gyrus. Our results, as well as further studies of the excitatory or inhibitory balance of microcircuits, relating the redox systems on the periphery with the distant regions of the brain might allow for predicting potential biomarkers of neuropsychiatric diseases, including schizophrenia. To the best of our knowledge, our study is the first to identify an objective molecular biomarker of schizophrenia outcome.

Disrupted hemispheric connectivity specialization in patients with major depressive disorder: Evidence from the REST-meta-MDD Project.

BACKGROUND: Functional specialization is a feature of human brain for understanding the pathophysiology of major depressive disorder (MDD). The degree of human specialization refers to within and cross hemispheric interactions. However, most previous studies only focused on interhemispheric connectivity in MDD, and the results varied across studies. Hence, brain functional connectivity asymmetry in MDD should be further studied. METHODS: Resting-state fMRI data of 753 patients with MDD and 451 healthy controls were provided by REST-meta-MDD Project. Twenty-five project contributors preprocessed their data locally with the Data Processing Assistant State fMRI software and shared final indices. The parameter of asymmetry (PAS), a novel voxel-based whole-brain quantitative measure that reflects inter- and intrahemispheric asymmetry, was reported. We also examined the effects of age, sex and clinical variables (including symptom severity, illness duration and three depressive phenotypes). RESULTS: Compared with healthy controls, patients with MDD showed increased PAS scores (decreased hemispheric specialization) in most of the areas of default mode network, control network, attention network and some regions in the cerebellum and visual cortex. Demographic characteristics and clinical variables have significant effects on these abnormalities. LIMITATIONS: Although a large sample size could improve statistical power, future independent efforts are needed to confirm our results. CONCLUSIONS: Our results highlight the idea that many brain networks contribute to broad clinical pathophysiology of MDD, and indicate that a lateralized, efficient and economical brain information processing system is disrupted in MDD. These findings may help comprehensively clarify the pathophysiology of MDD in a new hemispheric specialization perspective.

[Comparison of the effect between electroacupuncture and NSAIDs on pain memory based on cAMP/PKA/CREB pathway in anterior cingulate gyrus].

OBJECTIVE: To observe the direct intervention effects of electroacupuncture (EA) and non-steroid anti-inflammatory drugs (NSAIDs) on pain memory, and to explore their effects on cAMP/PKA/cAMP pathway in anterior cingulate gyrus (ACC). METHODS: Fifty clean healthy male SD rats were randomly divided into a control group, a model group, an indomethacin group, an EA group and a sham EA group, 10 rats in each group. Except the control group, the pain memory model was established in the remaining four groups by twice injection of carrageenan at foot; 0.1 mL of 2%λ-carrageenan was subcutaneously injected at the left foot of rats; 14 days later, when the pain threshold of rats of each group returned to the basic level, the second injection was performed with the same procedure. The rats in the EA group were treated with EA at bilateral "Zusanli" (ST 36) for 30 min; the rats in the indomethacin group was treated with indomethacin intragastric administration with the dose of 3 mg/kg; the rats in the sham EA group was treated with EA without electricity at the point 0.3 mm forward "Zusanli" (ST 36) with the depth of 2 mm for 30 min; the rats in the control group was not given any invention. All the above interventions were performed 5 h, 1 d, 2 d and 3 d after the second injection of 2% λ-carrageenan. The left-side paw withdrawal thresholds (PWT) were observed before the first injection, 4 h, 3 d, 5 d after the first injection, before the second injection and 4 h, 1 d, 2 d, 3 d after the second injection. Three days after the second injection, the number of positive cells of cAMP, p-PKA, p-CREB and the number of positive cells of protein co-expression in the right ACC brain area were detected by immunofluorescence, and the relative protein expression of p-PKA and p-CREB were detected by Western blot. RESULTS: Compared with the control group, the PWTs in the model group decreased significantly 4 h, 3 d and 5 d after the first injection and 1 d, 2 d and 3 d after the second injection (P<0.05); compared with the control group, the positive expression of cAMP, p-PKA and p-CREB in the right ACC brain area in the model group increased significantly (P<0.05), and the number of positive cells of the co-expression of cAMP/p-PKA and p-PKA/p-CREB also increased significantly (P<0.05). Compared with the model group, indomethacin group and sham EA group, the PWTs in the EA group were increased significantly 1 d, 2 d and 3 d after the second injection (P<0.05); compared with the model group, indomethacin group and sham EA group, the positive expression of p-PKA and p-CREB in the right ACC brain area in the EA group decreased significantly (P<0.05), and the number of positive cells of co-expression of cAMP/p-PKA and p-PKA/p-CREB was decreased significantly (P<0.05). Compared with the model group and sham EA group, the positive expression of cAMP in the right ACC brain area was decreased in the EA group (P<0.05). CONCLUSION: EA have a direct intervention effect on pain memory, which have significant advantage over NSAIDs in the treatment of chronic pain. The advantage effect of EA on pain memory may be related to the inhibition of cAMP/PKA/CREB pathway in ACC area.

Altered Intra- and Inter-regional Functional Connectivity of the Anterior Cingulate Gyrus in Patients With Tremor-Dominant Parkinson's Disease Complicated With Sleep Disorder.

Objective: To investigate changes in brain function at the regional and whole-brain levels in patients with tremor-dominant Parkinson's disease (TDPD) complicated by sleep disorder (SD) by regional homogeneity (ReHo) and functional connectivity (FC) analysis of whole-brain resting-state functional magnetic resonance images. Materials and Methods: ReHo and seed-based FC analyses were conducted among 32 patients with TDPD and SD (TDPD-SD), 24 with TDPD and no SD (TDPD-NSD), and 23 healthy controls (HCs) to assess spontaneous brain activity and network-level brain function. Correlation analyses were used to examine the associations between brain activity and the clinical data. Results: Anterior cingulate gyrus (ACC) ReHo values differed significantly among the groups. ACC ReHo values were increased in TDPD-SD vs. HC and TDPD-SD vs. TDPD-NSD. ACC ReHo values were reduced in TDPD-NSD vs. HC. TDPD-SD ReHo values were positively correlated with Pittsburgh Sleep Quality Index (PSQI) scores (r = 0.41, p = 0.020) but negatively correlated with Parkinson's Disease Sleep Scale (PDSS) scores (r = -0.38, p = 0.030). FC analysis using ACC as a mask showed that FC of the left olfactory cortex (L-OC), right straight gyrus (R-SG), right superior parietal gyrus (R-SPG), and right precuneus differed significantly among the groups. FC values between R-SG and ACC were significantly lower in TDPD-SD than in TDPD-NSD, while the FC of L-OC and R-OC with ACC was significantly lower in TDPD-SD than in HC. FC between ACC and L-OC, R-SPG, and the right precuneus was lower in TDPD-NSD than in HC. There was no correlation between the FC values and other clinical data in any of the groups. Conclusion: Localized abnormal activity in TDPD-SD was chiefly triggered by ACC. The change in the ReHo of ACC is closely related to the severity of TDPD-associated SD, revealing the role of this region as a regulator of the sleep mechanism in TDPD. Significant abnormal FC was found between R-SG and ACC in TDPD-SD but was not shown to correlate with clinical data.

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.

Executive Functions Rating Scale and Neurobiochemical Profile in HIV-Positive Individuals.

The set of complex cognitive processes, that are necessary for the cognitive control of behavior, known as executive functions (EF), are traditionally associated with the prefrontal cortex and commonly assessed with laboratory based tests and conventional neuroimaging. In an effort to produce a more complete and ecologically valid understanding of executive functioning, the rating scales have been developed in order to assess the behavioral aspects of EF within an everyday real-world context. The main objective of this study was to examine the relationship between behavioral aspects of EF measured by rating scale and neurometabolic profile in neurologically asymptomatic HIV-positive individuals under cART, measured using multi-voxel magnetic resonance spectroscopy (mvMRS). The sample comprised 39 HIV-positive adult male participants, stable on cART and 39 healthy HIV-negative volunteers. Both groups completed the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A). HIV-positive group additionally underwent long-echo three-dimensional mvMRS to determine neurobiochemical profile in the anterior cingulate gyrus (ACG) of both hemispheres. Three dominant neurometabolites were detected: N-acetyl aspartate (NAA), the neuronal marker; choline (Cho), the marker of membrane metabolism and gliosis and creatine (Cr), the reference marker. Ratios of NAA/Cr and Cho/Cr were analyzed. The initially detected significant correlations between age, current CD4, BRIEF-A subscales Inhibit, Shift, Emotional Control, Plan/Organize, Self Monitoring and ratios of NAA/Cr and Cho/Cr in the dorsal and ventral part of the ACG, were lost after the introduction of Bonferroni corrections. Also, there were no significant differences between HIV-positive and HIV-negative group on any of BRIEF-A subscales. Such results possibly imply that stable cART regimen contributes to preservation of behavioral aspects of EF in asymptomatic HIV-positive individuals. Even though a subtle deficit in some aspects of EF might exist, it would not be manifest if behavioral aspect was assessed using EF rating scale. Further explanation might be that expected HIV-related changes in neurometabolic profile of the ACG under cART are not reflected in those behavioral aspects that are measurable by EF rating scale.

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 ±â€¯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 ±â€¯6.6 (PPD) and 23.0 ±â€¯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 ±â€¯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.

Anterior paracingulate and cingulate cortex mediates the effects of cognitive load on speech sound discrimination.

Perceiving speech while performing another task is a common challenge in everyday life. How the brain controls resource allocation during speech perception remains poorly understood. Using functional magnetic resonance imaging (fMRI), we investigated the effect of cognitive load on speech perception by examining brain responses of participants performing a phoneme discrimination task and a visual working memory task simultaneously. The visual task involved holding either a single meaningless image in working memory (low cognitive load) or four different images (high cognitive load). Performing the speech task under high load, compared to low load, resulted in decreased activity in pSTG/pMTG and increased activity in visual occipital cortex and two regions known to contribute to visual attention regulation-the superior parietal lobule (SPL) and the paracingulate and anterior cingulate gyrus (PaCG, ACG). Critically, activity in PaCG/ACG was correlated with performance in the visual task and with activity in pSTG/pMTG: Increased activity in PaCG/ACG was observed for individuals with poorer visual performance and with decreased activity in pSTG/pMTG. Moreover, activity in a pSTG/pMTG seed region showed psychophysiological interactions with areas of the PaCG/ACG, with stronger interaction in the high-load than the low-load condition. These findings show that the acoustic analysis of speech is affected by the demands of a concurrent visual task and that the PaCG/ACG plays a role in allocating cognitive resources to concurrent auditory and visual information.

A Longitudinal 1H-MRS Study of the Anterior Cingulate Gyrus in Child and Adolescent Victims of Multiple Forms of Violence.

BACKGROUND: The anterior cingulate gyrus is involved in the extinction of conditioned fear responses and is implicated in the pathophysiology of posttraumatic stress disorder. The expression of N-acetylaspartate and choline may be altered in the anterior cingulate gyri of children and adolescents with posttraumatic stress disorder. METHODS: We conducted a proton magnetic resonance spectroscopy study, longitudinally investigating N-acetylaspartate/creatine and choline/creatine ratios in the anterior cingulate gyri of children and adolescents, aged from 8 to 12 years, who had been exposed to various forms of violence or were non-trauma control. Based on baseline posttraumatic stress symptoms ("sub-clinical"), participants were divided into two groups: posttraumatic stress (n = 19) and control (n = 19). Proton magnetic resonance spectroscopy scans were repeated a year later in trauma exposed participants. Trauma assessments included the Childhood Trauma Questionnaire. RESULTS: Exploratory analyses revealed a significant negative correlation between follow-up anterior cingulate gyrus N-acetylaspartate/creatine and Childhood Trauma Questionnaire scores in posttraumatic stress (r = -0.62, p = 0.01) but not control group (r = 0.16, p = 0.66). However, we found no significant differences in anterior cingulate gyrus N-acetylaspartate/creatine or choline/creatine between posttraumatic stress and control. In addition, there were no significant effects of time, group, or time-by-group interactions. CONCLUSIONS: In this pediatric population, anterior cingulate gyrus N-acetylaspartate/creatine and choline/creatine were not affected by posttraumatic stress and on average these metabolites remained stable over time. However, the study provided intriguing preliminary evidence revealing that participants suffering from posttraumatic stress at baseline have shown, a year later, reduced anterior cingulate gyrus N-acetylaspartate/creatine among those with high trauma severity. This pilot evidence warrants replication in future studies to confirm these findings and to determine the longitudinal effects and interactions between childhood posttraumatic stress and trauma.