Left Lateral Occipital Cortex Research Articles

Superior temporal sulcus folding, functional network connectivity, and autistic-like traits in a non-clinical population.

Autistic-like traits (ALT) are prevalent across the general population and might be linked to some facets of a broader autism spectrum disorder (ASD) phenotype. Recent studies suggest an association of these traits with both genetic and brain structural markers in non-autistic individuals, showing similar spatial location of findings observed in ASD and thus suggesting a potential neurobiological continuum. In this study, we first tested an association of ALTs (assessed with the AQ questionnaire) with cortical complexity, a cortical surface marker of early neurodevelopment, and then the association with disrupted functional connectivity. We analysed structural T1-weighted and resting-state functional MRI scans in 250 psychiatrically healthy individuals without a history of early developmental disorders, in a first step using the CAT12 toolbox for cortical complexity analysis and in a second step we used regional cortical complexity findings to apply the CONN toolbox for seed-based functional connectivity analysis. Our findings show a significant negative correlation of both AQ total and AQ attention switching subscores with left superior temporal sulcus (STS) cortical folding complexity, with the former being significantly correlated with STS to left lateral occipital cortex connectivity, while the latter showed significant positive correlation of STS to left inferior/middle frontal gyrus connectivity (n = 233; all p < 0.05, FWE cluster-level corrected). Additional analyses also revealed a significant correlation of AQ attention to detail subscores with STS to left lateral occipital cortex connectivity. Phenotyping might affect association results (e.g. choice of inventories); in addition, our study was limited to subclinical expressions of autistic-like traits. Our findings provide further evidence for biological correlates of ALT even in the absence of clinical ASD, while establishing a link between structural variation of early developmental origin and functional connectivity.

Cortical morphological alterations in cognitively normal Parkinson’s disease with severe hyposmia

Olfactory dysfunction is a common non-motor symptom of Parkinson’s disease(PD) and may hold valuable insights into the disease’s underlying pathophysiology. This study aimed to investigate cortical morphometry alterations in PD patients with severe hyposmia(PD-SH) and mild hyposmia(PD-MH) using surface-based morphometry(SBM) methods. Participants included 36 PD-SH patients, 38 PD-MH patients, and 40 healthy controls(HCs). SBM analysis revealed distinct patterns of cortical alterations in PD-SH and PD-MH patients. PD-MH patients exhibited reduced cortical thickness in the right supramarginal gyrus, while PD-SH patients showed widespread cortical thinning in regions including the bilateral pericalcarine cortex, bilateral lingual gyrus, left inferior parietal cortex, left lateral occipital cortex, right pars triangularis, right cuneus, and right superior parietal cortex. Moreover, PD-SH patients displayed reduced cortical thickness in the right precuneus compared to PD-MH patients. Fractal dimension analysis indicated increased cortical complexity in PD-MH patients’ right superior temporal cortex and right supramarginal gyrus, as well as decreased complexity in the bilateral postcentral cortex, left superior parietal cortex, and right precentral cortex. Similarly, cortical gyrification index and cortical sulcal depth exhibited heterogeneous patterns of changes in PD-SH and PD-MH patients compared to HCs. These findings underscore the multifaceted nature of olfactory impairment in PD, with distinct patterns of cortical morphometry alterations associated with different degrees of hyposmia. The observed discrepancies in brain regions showing alterations reflect the complexity of PD’s pathophysiology. These insights contribute to a deeper understanding of olfactory dysfunction in PD and provide potential avenues for early diagnosis and targeted interventions.

Association of Arterial Stiffness Index and Brain Structure in the UK Biobank: A 10-Year Retrospective Analysis.

Arterial stiffening and changes in brain structure both occur with normal aging and can be exacerbated via acquired health conditions. While cross-sectional associations exist, the longitudinal relationship between arterial stiffness and brain structure remains unclear. In this study, we investigated 1) associations between baseline arterial stiffness index (ASI) and brain structure (global and regional grey matter volumes (GMV), white matter hyperintensities (WMH)) 10-years post-baseline (10.4±0.8 years) and 2) associations between the 10-year change in ASI from baseline and brain structure 10-years post-baseline in 650 healthy middle- to older-aged adults (53.4±7.5 years) from the UK Biobank. We observed significant associations between baseline ASI and GMV (p<0.001) and WMH (p=0.0036) 10-years post-baseline. No significant associations between 10-year change in ASI and brain structure (global GMV p=0.24; WMH volume p=0.87) were observed. There were significant associations of baseline ASI in 2 of 60 regional brain volumes analyzed (right posterior superior temporal gyrus p=0.001; left superior lateral occipital cortex p<0.001). Strong associations with baseline ASI, but not changes in ASI over 10-years, suggest arterial stiffness at the entry point of older adulthood is more impactful on brain structure 10-years later compared to age-related stiffening. Based on these associations, we suggest clinical monitoring and potential intervention for reducing arterial stiffness should occur in midlife to reduce vascular contributions to structural changes in the brain, supporting a healthy trajectory of brain aging. Our findings also support use of ASI as a surrogate for gold standard measures in showing overall relationships between arterial stiffness and brain structure.

Resolving autism spectrum disorder (ASD) through brain topologies using fMRI dataset with multi-layer perceptron (MLP)

Autism is a neurodevelopmental disorder that manifests in individuals during childhood and has enduring consequences for their social interactions and communication. The prediction of Autism Spectrum Disorder (ASD) in individuals based on the differences in brain networks and activities have been studied extensively in the recent past, however, with lower accuracies. Therefore in this research, identification at the early stage through computer-aided algorithms to differentiate between ASD and TD patients is proposed. In order to identify features, a Multi-Layer Perceptron (MLP) model is developed which utilizes logistic regression on characteristics extracted from connectivity matrices of subjects derived from fMRI images. The features that significantly contribute to the classification of individuals as having Autism Spectrum Disorder (ASD) or typically developing (TD) are identified by the logistic regression model. To enhance emphasis on essential attributes, an AND operation is integrated. This involves selecting features demonstrating statistical significance across diverse logistic regression analyses conducted on various random distributions. The iterative approach contributes to a comprehensive understanding of relevant features for accurate classification. By implementing this methodology, the estimation of feature importance became more dependable, and the potential for overfitting is moderated through the evaluation of model performance on various subsets of data. It is observed from the experimentation that the highly correlated Left Lateral Occipital Cortex and Right Lateral Occipital Cortex ROIs are only found in ASD. Also, it is noticed that the highly correlated Left Cerebellum Tonsil and Right Cerebellum Tonsil are only found in TD participants. Among the MLP classifier, a recall of 82.61 % is achieved followed by Logistic Regression with an accuracy of 72.46 %. MLP also stands out with a commendable accuracy of 83.57 % and AUC of 0.978.

Visual Cortical Thickness Increases with Prolonged Artificial Vision Restoration.

The Argus II retinal prosthesis restores visual perception to late blind patients. It has been shown that structural changes occur in the brain due to late-onset blindness, including cortical thinning in visual regions of the brain. Following vision restoration, it is not yet known whether these visual regions are reinvigorated and regain a normal cortical thickness or retain the diminished thickness from blindness. We evaluated the cortical thicknesses of ten Argus II Retinal Prostheses patients, ten blind patients, and thirteen sighted participants. The Argus II patients on average had a thicker left Cuneus Cortex and Lateral Occipital Cortex relative to the blind patients. The duration of the Argus II use (time since implant in active users) significantly partially correlated with thicker visual cortical regions in the left hemisphere. Furthermore, in the two case studies (scanned before and after implantation), the patient with longer device use (44.5 months) had an increase in the cortical thickness of visual regions, whereas the shorter-using patient did not (6.5 months). Finally, a third case, scanned at three time points post-implantation, showed an increase in cortical thickness in the Lateral Occipital Cortex between 43.5 and 57 months, which was maintained even after 3 years of disuse (106 months). Overall, the Argus II patients' cortical thickness was on average significantly rejuvenated in two higher visual regions and, patients using the implant for a longer duration had thicker visual regions. This research raises the possibility of structural plasticity reversing visual cortical atrophy in late-blind patients with prolonged vision restoration.

Cortical Macro- and Microstructural Changes in Parkinson's Disease with Probable Rapid Eye Movement Sleep Behavior Disorder.

Evidence regarding cortical atrophy patterns in Parkinson's disease (PD) with probable rapid eye movement sleep behavior disorder (RBD) (PD-pRBD) remains scarce. Cortical mean diffusivity (cMD), as a novel imaging biomarker highly sensitive to detecting cortical microstructural changes in different neurodegenerative diseases, has not been investigated in PD-pRBD yet. The aim was to investigate cMD as a sensitive measure to identify subtle cortical microstructural changes in PD-pRBD and its relationship with cortical thickness (CTh). Twenty-two PD-pRBD, 31 PD without probable RBD (PD-nonpRBD), and 28 healthy controls (HC) were assessed using 3D T1-weighted and diffusion-weighted magnetic resonance imaging on a 3-T scanner and neuropsychological testing. Measures of cortical brain changes were obtained through cMD and CTh. Two-class group comparisons of a general linear model were performed (P < 0.05). Cohen's d effect size for both approaches was computed. PD-pRBD patients showed higher cMD than PD-nonpRBD patients in the left superior temporal, superior frontal, and precentral gyri, precuneus cortex, as well as in the right middle frontal and postcentral gyri and paracentral lobule (d > 0.8), whereas CTh did not detect significant differences. PD-pRBD patients also showed increased bilateral posterior cMD in comparison with HCs (d > 0.8). These results partially overlapped with CTh results (0.5 < d < 0.8). PD-nonpRBD patients showed no differences in cMD when compared with HCs but showed cortical thinning in the left fusiform gyrus and lateral occipital cortex bilaterally (d > 0.5). cMD may be more sensitive than CTh displaying significant cortico-structural differences between PD subgroups, indicating this imaging biomarker's utility in studying early cortical changes in PD. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Increased ventral anterior insular connectivity to sports betting availability indexes problem gambling.

With the advent of digital technologies, online sports betting is spurring a fast-growing expansion. In this study, we examined how sports betting availability modulates the brain connectivity of frequent sports bettors with [problem bettors (PB)] or without [non-problem bettors (NPB)] problematic sports betting. We conducted functional connectivity analyses centred on the ventral anterior insular cortex (vAI), a brain region playing a key role in the dynamic interplay between reward-based processes. We re-analysed a dataset on sports betting availability undertaken in PB (n = 30) and NPB (n = 35). Across all participants, we observed that sports betting availability elicited positive vAI coupling with extended clusters of brain activation (encompassing the putamen, cerebellum, occipital, temporal, precentral and central operculum regions) and negative vAI coupling with the orbitofrontal cortex. Between-group analyses showed increased positive vAI coupling in the PB group, as compared with the NPB group, in the left lateral occipital cortex, extending to the left inferior frontal gyrus, the anterior cingulate gyrus and the right frontal pole. Taken together, these results are in line with the central assumptions of triadic models of addictions, which posit that the insular cortex plays a pivotal role in promoting the drive and motivation to get a reward by 'hijacking' goal-oriented processes toward addiction-related cues. Taken together, these findings showed that vAI functional connectivity is sensitive not only to gambling availability but also to the status of problematic sport betting.

Different emotion regulation strategies mediate the relations of corresponding connections within the default-mode network to sleep quality.

Despite a long history of interest in the relation of emotion regulation to sleep quality, how different strategies link with sleep quality at the neural level is still poorly understood. Thus, we utilized the process model of emotion regulation as an organizing framework for examining the neurological underpinning of the links between the two emotion regulation strategies and sleep quality. 183 young adults (51.7% females, Mage = 22.16) were guided to undergo the MRI scans and then complete the Pittsburgh Sleep Quality Index (PSQI) and the emotion regulation Questionnaire (ERQ) formed by two dimensions: cognitive reappraisal and expressive suppression. Results found that emotion regulation mediated the association between functional connectivity within the intrinsic default-mode network (DMN) and sleep quality. Specifically, rsFC analysis showed that cognitive reappraisal was positively correlated with rsFC within DMN, including left superior temporal gyrus (lSTG)-left lateral occipital cortex (lLOC), lSTG-left anterior cingulate gyrus (lACG), right lateral occipital cortex (rLOC)-left middle frontal gyrus (lMFG), and rLOC-lSTG. Further mediation analysis indicated a mediated role of cognitive reappraisal in the links between the four connectivity within the DMN and sleep quality. In addition, expressive suppression was positively correlated with rsFC within DMN, including left precuneus cortex (lPrcu)-right Temporal Pole (rTP) and lPrcu- lSTG. Further mediation analysis indicated a mediated role of expressive suppression in the links between the two connectivity within the DMN and sleep quality. Overall, this finding supports the process model of emotion regulation in that the effects of reappraisal and suppression have varying neural circuits that impact that strategy's effect on sleep quality.

Neural Correlates of Trait Impulsivity among Adult Healthy Individuals.

: Impulsivity can be observed in individuals with or without mental illness. The discovery of neural correlates responsible for trait impulsivity can therefore help to understand the severity of psychiatric symptoms, personality characteristics and social adjustment. In this study, we aimed to identify the gray matter substrates of trait impulsivity in healthy individuals. : Seventy-five healthy individuals were enrolled. At baseline, trait impulsivity was assessed using the Barratt Impulsiveness Scale (BIS) and all participants underwent T1-weighted magnetic resonance imaging scan. Beck Anxiety Inventory (BAI), World Health Organization Quality of Life (WHOQOL-BREF) and Connor-Davidson Resilience Scale (CD-RISC) were also assessed. Mean cortical thickness (CT) and the local gyrification index (LGI) were calculated to perform whole-brain vertex-wise correlation analysis, which were performed to investigate the relationship between BIS scores and CT or LGI in each brain region. We also revealed the relationship between brain regions and psychological measurements. : Total BIS scores were significantly and negatively correlated with mean CT values in the left lateral occipital cortex (OC) and LGIs in the inferior frontal gyrus (IFG). Correlation analyses revealed that the lateral OC's mean CT values were negatively correlated with BAI scores and positively correlated with WHOQOL-BREF scores, while LGI in the IFG was positively correlated with CD-RISC scores. : Our study showed that trait impulsivity might be associated with the lateral OC and IFG in healthy individuals. Understanding the neural correlates of trait impulsivity could provide ways to expect high impulsivity, anxiety, and poor resilience in healthy adults.

Association between mild behavioral impairment and hippocampal structural covariance in amnestic mild cognitive impairment

AbstractBackgroundOur previous work reported that mild cognitive impairment (MCI) patients with multiple mild behavioral impairment (MBI) domain symptoms (complex group) revealed a higher risk of developing Alzheimer’s disease (AD) compared with those with no MBI symptoms (asymptomatic group) and cortical thinning in the parietal and frontal areas. However, MCI patients with only affective dysregulation (affective dysregulation group) were not associated with the risk of AD and revealed relative cortical thickening (Yoon EJ, Front Aging Neurosci 2023). To clarify relationships of cortical thickness changes and risk of progression to AD in MCI patients, we compared structural covariance patterns between hippocampal volume and cortical thickness among the MBI subgroups.MethodA total 201 older adults with amnestic MCI were classified based on profiles of MBI domain symptoms into asymptomatic, affective dysregulation, and complex groups. The FreeSurfer was used to estimate cortical thickness and volumes of hippocampal subfields (Fig 1). A vertex‐wise general linear interaction model was used to compare group map of covariance between volumes of hippocampus subfields and thickness at each of vertices. Correlations between the thickness in regions showing significant group differences and mini‐mental state examination (MMSE) scores were also assessed.ResultIn the affective dysregulation group, the structural covariance of left CA1, CA4/DG and molecular layer were increased in the left superior and inferior parietal cortex (Fig 2a), and the thickness of this region showed positive correlation with MMSE (spearman’s rho = 0.302, p‐value = 0.046). The structural covariance of left hippocampal tail for the affective dysregulation group was increased in left lateral occipital cortex, and those for the complex group was increased in left inferior parietal and lateral occipital cortex compared with the asymptomatic group (Fig 2b). Also, the complex group revealed decreased structural covariance of right subiculum with left rostral middle frontal cortex (Fig 2c).ConclusionOur findings suggest that the lateral parietal area might have an important role in compensatory mechanisms in the affective dysregulation group. On the other hand, the complex group may be associated with more advanced stages of disease in which the patterns of increased covariance of hippocampal subfields were disappeared or inversed.

ApoB‐related Sulcal depth Patterns Contributed to Executive Function and Plasma Biomarkers of Alzheimer’s disease

AbstractBackgroundAs the cerebral cortex is an important indicator of the pathological changes of AD, ApoB, ApoA1, ApoB/ApoA1 and blood Alzheimer’s biomarkers have been proved to be important markers of AD.MethodWe analyzed data from 21 patients with SCD enrolled in the 500 nm light therapy cohort who filled a battery of neuropsychological tests and had apolipoproteins, plasma Alzheimer’s biomarkers, and gene levels assessed at the time of their baseline 3T MRI scans. The sulcal depth and cortical thickness were obtained using the vertex‐based approach with the CAT12 toolbox (in SPM12).ResultAt corrected thresholds (p &lt; 0.05, FWE‐corrected), there were significant positive correlations between ApoB and sulcal depth in the lateral occipital cortex, and between ApoB/ApoA1 and sulcal depth in the left lateral occipital cortex. In addition, we found a significant negative correlation between shape trails test part B (STT‐B) time and sulcal depth in the left lateral occipital cortex (β = ‐0.502, p = 0.040). Moreover, the plasma Aβ42 was positively related to sulcal depth (β = 0.493, p = 0.044) and plasma p‐tau181 was negatively related to the sulcal depth (β = ‐0.592, p = 0.012) in the left lateral occipital cortex. There was no relationship between cortical thickness and apolipoproteins or any of the biomarkers.ConclusionApoB and ApoB/ApoA1 influence sulcal depth in the left lateral occipital cortex where the sulcal depth may relate to the executive function and plasma Alzheimer’s biomarkers in SCD.

15 Socioeconomic Status in Association to Memory-Related Brain Activation in Middle-Aged Adults

Objective:Socioeconomic status (SES) has been recognized as an important factor in psychological research within the last few decades. Past literature recognizes that having lower SES can have a negative impact on many aspects of one’s health, especially in diseases related to brain aging. A recent avenue for research regarding SES and the brain-behavior relationship suggests that socioeconomic status can act as a moderator for brain activation during task performance. The hypothesis for this project was that there will be a negative correlational relationship between brain activity and SES when controlling for participants’ age, sex, and performance on the episodic memory tasks, but a positive correlation between task performance and SES was expected.Participants and Methods:With 100 middle-aged healthy adults from the Reference Ability Neural Network (RANN) study (53 male and 47 female, age M=48.0 +/- 7.55 years), three episodic memory fMRI tasks were performed and studied in relation to SES and age. The tasks were Logical Memory, Word Order, and Pair Associates tasks that involved episodic memory for story details, order of words presented, and pairing of words, respectively. We quantified memory performance with average accuracy from performance of the three tasks. We used the FSL software to preprocess and perform voxel-wise group analysis. All brain activation analyses were corrected for multiple comparison using cluster thresholds in FSL.Results:Correlation between SES and memory performance was found to be marginally significant (R=.188, p=.061). All tasks had areas of positively correlated activation for age. The Logical Memory task had multiple areas of brain activation that were positively correlated with age, particularly at the lateral occipital cortex, lingual gyrus, and the occipital fusiform gyrus, all areas that underlie visual processing. There were no areas of correlated brain activation for SES, sex, and task performance for the Pair Associates and Logical Memory tasks. Brain activation for the Word order task in the left precuneous cortex and the right middle frontal gyrus, left lateral occipital cortex, left occipital fusiform gyrus, and parts of the lingual gyrus was positively correlated with memory performance when controlled for age, sex, and SES.Conclusions:The hypothesis was not entirely supported by the results of this study, but the marginal effect between SES and memory performance can suggest that SES may affect memory performance within middle-aged adults. While we did not find a brain association with SES in this age group, we observed regions that underlie task performance. Further research can be done on possible moderating effects of Socioeconomic Status on memory and executive function with structural neuroimaging to further investigate the effects of SES on cognition.

46 Resting State FC in the Default Mode Networks: A Prediction Model for Elevated Aggression from Connectivity Metrics and Neurocognitive Performance Across Multiple Stages of Recovery in mild TBI

Objective:Mild traumatic brain injury (mTBI) remains one of the most prevalent brain injuries, affecting approximately one-in-sixty Americans. Previous studies have shown an association between white matter integrity and aggression at chronic stages (either 6-months or 12 months post-mTBI) however, the association between white matter axonal damage, neuropsychological outcomes, and elevated aggression in multiple stages since time-since-injury (TSI) is unclear. We hypothesized that functional connectivity between the default mode network (DMN), a key brain network involved in cognitive, self-reflective, and emotional processes, and other cortical regions would predict elevated aggression and emotional disturbances across multiples stages of recovery in mild TBI.Participants and Methods:Participants healthy controls (HC: n=35 total [15 male, 20 female], age M=24.40, SD=5.95; mTBI: n=121 total [43 male; 78 female], age M = 24.76, SD=7.48). Participants completed a cross-sectional study design at specific post-injury time points ranging from (2W, 1M,3M,6M,12M). Participants completed a comprehensive neuropsychological battery and a neuroimaging session, including resting state functional connectivity (FC). Here, we focus on the FC outcomes for the DMN. During the neuropsychological assessment, participants completed tests that measured learning and memory, speed of information processing, executive function, and attention. To predict neuropsychological performance from brain connectivity, we conducted a series of stepwise linear regression analyses with the 11 functional brain connections (extracted as Fisher’s z-transformed correlations between regions) as predictors and each of the 13 neurocognitive factor scores separately.Results:Consistent with our hypothesis, one predictor materialized as significant (R = .187, R2 = .035, F = 5.55, p = .020) for the Total Sample. Largely, positive connectivity between Right Inferior Frontal Gyrus and the PCC (seed) was associated with increased aggression in the Total Sample of all participants (ß = .187, t = 2.36, p = .020). One predictor materialized as significant in Individuals the 2W group, (R = .719, R2 = .518, F = 8.58, p = .019). In general, greater negative (anticorrelated) connectivity between the Left Lateral Occipital Cortex (ß = -.719, t = -2.93, p = .019) and the PCC (seed) and was associated with greater aggression at 2W, but no predictors emerged at 1M or 3M. Individuals in the 6M group showed one significant predictor (R = .675, R2 = .455, F = 16.71, p = .001). Specifically, greater positive connectivity between the Right Lateral Occipital Cortex (/? = .675, t = 4.09, p = .001) and PCC (seed) was associated with greater aggression at 6M. No associations were evident at 12M.Conclusions:Overall, these findings suggest functional connectivity between the posterior hub of the DMN and cortical regions within the occipital cortex was predictive of higher aggression in individuals with mTBI. However, the direction of this connectivity differed at 2W versus 6M, suggesting a complex process of recovery that may contribute differentially to aggression in patients with mTBI. As these regions are involved in self-consciousness and visual perception, this may point toward future avenues for aiding in functional recovery of emotional dysregulation in patients with persistent post-concussion syndrome.

Modulation of associations between education years and cortical volume in Alzheimer's disease vulnerable brain regions by Aβ deposition and APOE ε4 carrier status in cognitively normal older adults.

Education years, as a measure of cognitive reserve, have been shown to affect the progression of Alzheimer's disease (AD), both pathologically and clinically. However, inconsistent results have been reported regarding the association between years of education and intermediate structural changes in AD-vulnerable brain regions, particularly when AD risk factors were not considered during the preclinical phase. This study aimed to examine how Aβ deposition and APOE ε4 carrier status moderate the relationship between years of education and cortical volume in AD-vulnerable regions among cognitively normal older adults. A total of 121 participants underwent structural MRI, [18F] flutemetamol PET-CT imaging, and neuropsychological battery assessment. Multiple regression analysis was conducted to examine the interaction between years of education and the effects of potential modifiers on cortical volume. The associations between cortical volume and neuropsychological performance were further explored in subgroups categorized based on AD risk factors. The cortical volume of the left lateral occipital cortex and bilateral fusiform gyrus demonstrated a significant differential association with years of education, depending on the presence of Aβ deposition and APOE ε4 carrier status. Furthermore, a significant relationship between the cortical volume of the bilateral fusiform gyrus and AD-nonspecific cognitive function was predominantly observed in individuals without AD risk factors. AD risk factors exerted varying influences on the association between years of education and cortical volume during the preclinical phase. Further investigations into the long-term implications of these findings would enhance our understanding of cognitive reserves in the preclinical stages of AD.

Elevated brain temperature under severe heat exposure impairs cortical motor activity and executive function

BackgroundExcessive heat exposure can lead to hyperthermia in humans, which impairs physical performance and disrupts cognitive function. While heat is a known physiological stressor, it is unclear how severe heat stress affects brain physiology and function. MethodsEleven healthy participants were subjected to heat stress from prolonged exercise or warm water immersion until their rectal temperatures (Tre) attained 39.5°C, inducing exertional or passive hyperthermia, respectively. In a separate trial, blended ice was ingested before and during exercise as a cooling strategy. Data were compared to a control condition with seated rest (normothermic). Brain temperature (Tbr), cerebral perfusion, and task-based brain activity were assessed using magnetic resonance imaging techniques. ResultsTbr in motor cortex was found to be tightly regulated at rest (37.3°C ± 0.4°C (mean ± SD)) despite fluctuations in Tre. With the development of hyperthermia, Tbr increases and dovetails with the rising Tre. Bilateral motor cortical activity was suppressed during high-intensity plantarflexion tasks, implying a reduced central motor drive in hyperthermic participants (Tre = 38.5°C ± 0.1°C). Global gray matter perfusion and regional perfusion in sensorimotor cortex were reduced with passive hyperthermia. Executive function was poorer under a passive hyperthermic state, and this could relate to compromised visual processing as indicated by the reduced activation of left lateral-occipital cortex. Conversely, ingestion of blended ice before and during exercise alleviated the rise in both Tre and Tbr and mitigated heat-related neural perturbations. ConclusionSevere heat exposure elevates Tbr, disrupts motor cortical activity and executive function, and this can lead to impairment of physical and cognitive performance.

Correlation analysis between 18F-fluorodeoxyglucose positron emission tomography and cognitive function in first diagnosed Parkinson's disease patients.

Evaluation of the correlation between 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG PET) and cognitive function in first-diagnosed and untreated Parkinson's disease (PD) patients. This cross-sectional study included 84 first diagnosed and untreated PD patients. The individuals were diagnosed by movement disorder experts based on the 2015 MDS Parkinson's disease diagnostic criteria. The patients also underwent 18F-FDG PET scans and clinical feature assessments including the Montreal Cognitive Assessment (MoCA) scale. Glucose metabolism rates were measured in 26 brain regions using region of interest (ROI) and pixel-wise analyses with displayed Z scores. The cognitive function was assessed by professionals using the MoCA scale, which covers five cognitive domains. Spearman's linear correlation and linear regression models were used to compare the correlations between 18F-FDG metabolism in each brain region and cognitive domain, using SPSS 25.0 software. The results indicated a positive correlation between executive function and glucose metabolism in the lateral prefrontal cortex of the left hemisphere (p = 0.041). Additionally, a positive correlation between memory function and glucose metabolism in the right precuneus (p = 0.014), right lateral occipital cortex (p = 0.017), left lateral occipital cortex (p = 0.031), left primary visual cortex (p = 0.008), and right medial temporal cortex (p = 0.046). Further regression analysis showed that for every one-point decrease in the memory score, the glucose metabolism in the right precuneus would decrease by 0.3 (B = 0.30, p = 0.005), the glucose metabolism in the left primary visual cortex would decrease by 0.25 (B = 0.25, p = 0.040), the glucose metabolism in the right lateral occipital cortex would decrease by 0.38 (B = 0.38, p = 0.012), and the glucose metabolism in the left lateral occipital cortex would decrease by 0.32 (B = 0.32, p = 0.045). This study indicated that cognitive impairment in PD patients mainly manifests as changes in executive function, visual-spatial function and memory functions, while glucose metabolism mainly decreases in the frontal and posterior cortex. Further analysis shows that executive function is related to glucose metabolism in the left lateral prefrontal cortex. On the other hand, memory ability involves changes in glucose metabolism in a more extensive brain region. This suggests that cognitive function assessment can indirectly reflect the level of glucose metabolism in the relevant brain regions.

Brain structure underlying the empathizing-systemizing difference in children with autism spectrum disorder.

Behavioral research has shown that children with autism spectrum disorder (ASD) havea higher empathizing-systemizing difference(D score) than normal children. However, there is no research about the neuroanatomical mechanisms of the empathizing-systemizing difference in children with ASD. Participants comprised 41 children with ASD and 39 typically developing (TD) children aged 6‒12years. Empathizing-systemizing difference was estimated using the D score from the Chinese version of Children's Empathy Quotient and Systemizing Quotient. We quantified brain morphometry, including global and regional brain volumes and surface-based cortical measures (cortical thickness, surface area, and gyrification) via structural magnetic resonance imaging. We found that the D score was significantly negatively associated with amygdala gray matter volume [β = -0.16; 95% confidence interval (CI): -0.30, -0.02; P value = 0.030] in children with ASD. There was a significantly negative association between D score and gyrification in the left lateral occipital cortex (LOC) in children with ASD (B = -0.10; SE = 0.03; cluster-wise P value = 0.006) and a significantly positive association between D score and gyrification in the right fusiform in TD children (B = 0.10; SE = 0.03; cluster-wise P value = 0.022). Moderation analyses demonstrated significant interactions between D score and diagnosed group in amygdala gray matter volume (β = 0.19; 95% CI 0.04, 0.35; P value = 0.013) and left LOC gyrification (β = 0.11; 95% CI 0.05, 0.17; P value = 0.001) but not in right fusiform gyrification (β = 0.08; 95% CI -0.02, 0.17; P value = 0.105). Neuroanatomical variation in amygdala volume and gyrification of LOC could be potential biomarkers for the empathizing-systemizing difference in children with ASD but not in TD children. Large-scale neuroimaging studies are necessary to test the replicability of our findings.

Country-level gender inequality is associated with structural differences in the brains of women and men

Gender inequality across the world has been associated with a higher risk to mental health problems and lower academic achievement in women compared to men. We also know that the brain is shaped by nurturing and adverse socio-environmental experiences. Therefore, unequal exposure to harsher conditions for women compared to men in gender-unequal countries might be reflected in differences in their brain structure, and this could be the neural mechanism partly explaining women's worse outcomes in gender-unequal countries. We examined this through a random-effects meta-analysis on cortical thickness and surface area differences between adult healthy men and women, including a meta-regression in which country-level gender inequality acted as an explanatory variable for the observed differences. A total of 139 samples from 29 different countries, totaling 7,876 MRI scans, were included. Thickness of the right hemisphere, and particularly the right caudal anterior cingulate, right medial orbitofrontal, and left lateral occipital cortex, presented no differences or even thicker regional cortices in women compared to men in gender-equal countries, reversing to thinner cortices in countries with greater gender inequality. These results point to the potentially hazardous effect of gender inequality on women's brains and provide initial evidence for neuroscience-informed policies for gender equality.

5-HT4 Receptor Agonist Effects on Functional Connectivity in the Human Brain: Implications for Procognitive Action

BackgroundCognitive deficits are often comorbid with mood disorders and can cause significant functional impairment even after resolution of the primary mood symptoms. We do not currently have pharmacological treatments that adequately address these deficits. 5-HT4 receptor agonists show promise as potential procognitive agents in animal and early human translational studies. Optimal cognitive performance in humans is directly associated with appropriate functional connectivity between specific resting-state neural networks. However, so far the effect of 5-HT4 receptor agonism on resting-state functional connectivity (rsFC) in the brain in humans is unknown. MethodsWe collected resting-state functional magnetic resonance imaging scans from 50 healthy volunteers, of whom 25 received 6 days × 1 mg prucalopride (a highly selective 5-HT4 receptor agonist) and 25 received placebo in a randomized double-blind design. ResultsNetwork analyses identified that participants in the prucalopride group had enhanced rsFC between the central executive network and the posterior/anterior cingulate cortex. Seed analyses also showed greater rsFC between the left and right rostral anterior cingulate cortex and the left lateral occipital cortex, and reduced rsFC between the hippocampus and other default mode network regions. ConclusionsSimilar to other potentially procognitive medications, low-dose prucalopride in healthy volunteers appeared to enhance rsFC between regions involved in cognitive networks and reduce rsFC within the default mode network. This suggests a mechanism for the behavioral cognitive enhancement previously seen with 5-HT4 receptor agonists in humans and supports the potential for 5-HT4 receptor agonists to be used in clinical psychiatric populations.

Functional connectivity of brain structures in patients with anorexia nervosa based on resting state fMRI: prospective study

INTRODUCTION: This paper analyzes local and foreign literature on functional magnetic resonance imaging (fMRI) in patients with anorexia nervosa. Resting state fMRI results of the brain of patients with anorexia nervosa (AN) are presented.OBJECTIVE: To study functional connectivity in the networks in resting state in patients with AN.MATERIALS AND METHODS: 43 patients with anorexia nervosa aged 14 to 19 years were examined. The control group consisted of 31 healthy volunteers. The connectivity of the structures involved in the formation of the default mode brain network, frontoparietal and visual networks was analyzed. Statistics: Mathematical and statistical processing was applied in the programming environment of the Python programming language, using the Jupyter-notebook development environment and application modules for statistical analysis Pandas and Numpi. The main tools for statistical analysis of functional MRI were the specialized software package CONN-TOOLBOX.RESULTS: In the default mode network, a decrease in connectivity between the medial prefrontal cortex and the cluster including the angular gyrus and the supramarginal gyrus, and an increase in connectivity between the right lateral parietal cortex and the cluster including the left precentral and postcentral gyrus, were revealed. In the frontoparietal network, significant indicators of a decrease in connectivity between the right lateral prefrontal cortex and three clusters were obtained, including the poles of the frontal lobes, the left superior and middle frontal gyri, and the left lateral occipital cortex. In the visual network, there was a decrease in connectivity between the left lateral visual network and the cluster which includes mainly the lateral parts of the cerebellar hemispheres and its vermis, the right lateral visual network and the cluster which includes mainly the right and left lingual gyrus, cerebellar hemispheres and vermis.CONCLUSION: Our study showed a disruption of the functional connectivity in patients with AN, leading to visuospatial disorders and, as a result, a change in the complex process of setting goals, planning appropriate steps to these goals, and impaired cognitive control.