Left Occipital Cortex Research Articles

Reproducible Microstructural Changes in the Brain Associated With the Presence and Severity of Urologic Chronic Pelvic Pain Syndrome (UCPPS): A 3-Year Longitudinal Diffusion Tensor Imaging Study From the MAPP Network

Microstructural alterations have been reported in patients with urologic chronic pelvic pain syndrome (UCPPS). However, it isn't clear whether these alterations are reproducible within 6 months or whether long-term symptom improvement is associated with specific microstructural changes. Using data from the MAPP-II Research Network, the current study performed population-based voxel-wise DTI and probabilistic tractography in a large sample of participants from the multicenter cohort with UCPPS (N = 364) and healthy controls (HCs, N = 61) over 36 months. While fractional anisotropy (FA) differences between UCPPS patients and HCs were observed to be unique at baseline and 6-month follow-up visits, consistent aberrations in mean diffusivity (MD) were observed between UCPPS and HCs at baseline and repeated at 6 months. Additionally, compared to HCs, UCPPS patients showed stronger structural connectivity (SC) between the left postcentral gyrus and the left precuneus, and weaker SC from the left cuneus to the left lateral occipital cortex and the isthmus of the left cingulate cortex at baseline and 6-month. By 36 months, reduced FA and MD aberrations in these same regions were associated with symptom improvement in UCPPS. Together, results suggest changes in white matter microstructure may play a role in the persistent pain symptoms in UCPPS. PerspectiveThis longitudinal study identified reproducible, “disease-associated” patterns in altered mean diffusivity and abnormal microstructural connectivity in UCPPS comparing to HCs over 6 months. These differences were found in regions involved in sensory processing and integration and pain modulation, making it potentially amenable for clinical interventions that target synaptic and/or neuronal reorganization.

Non-invasive brain stimulation modulates GABAergic activity in neurofibromatosis 1

Neurofibromatosis 1 (NF1) is a single-gene disorder associated with cognitive phenotypes common to neurodevelopmental conditions such as autism. GABAergic dysregulation underlies working memory impairments seen in NF1. This mechanistic experimental study investigates whether application of anodal transcranial direct current stimulation (atDCS) can modulate GABA and working memory in NF1. Thirty-one NF1 adolescents 11–18 years, were recruited to this single-blind sham-controlled cross-over randomized trial. AtDCS or sham stimulation was applied to the left Dorsolateral Prefrontal Cortex (DLPFC) and MR Spectroscopy was collected before and after intervention in the left DLPFC and occipital cortex. Task-related functional MRI was collected before, during, and after stimulation. Higher baseline GABA+ in the left DLPFC was associated with faster response times on baseline working memory measures. AtDCS was seen to significantly reduced GABA+ and increase brain activation in the left DLPFC as compared to sham stimulation. Task performance was worse in the aTDCS group during stimulation but no group differences in behavioural outcomes were observed at the end of stimulation. Although our study suggests aTDCS modulates inhibitory activity in the DLPFC, further work is needed to determine whether repeated sessions of atDCS and strategies such as alternating current stimulation offer a better therapeutic approach.

Functional magnetic resonance imaging activation for different vergence eye movement subtypes.

Maddox suggested that there were four convergence subtypes, each driven by a different stimulus. The purpose of this study was to assess the neural correlates for accommodative convergence, proximal convergence (convergence stimulus provided), disparity convergence and voluntary convergence (no specific convergence stimulus provided) using functional magnetic resonance imaging (fMRI). Ten subjects (mean age=24.4 years) with normal binocular vision participated. The blood oxygenation level-dependent (BOLD) signals of the brain from fMRI scans were measured when subjects made vergence eye movements while: (1) alternately viewing letters monocularly where one eye viewed through a -2.00 D lens, (2) alternately viewing Difference of Gaussian targets monocularly at distance and near, (3) viewing random dot stereograms with increasing disparity and (4) voluntarily converging the eyes with binocular viewing. The accommodative convergence paradigm resulted in activation on the right side in the right fusiform cortex and the right middle occipital cortex. The proximal convergence stimulus mainly activated areas in the right occipital lobe. The disparity stimulus activated areas in the left occipital cortex and the left frontal cortex. Finally, the voluntary convergence paradigm resulted in activation primarily in the occipital lobe and mostly bilaterally. The accommodative, proximal, disparity and voluntary convergence paradigms resulted in activation in unique areas in the brain with functional MRI. Activation was found in more areas in the proximal and voluntary conditions compared with the accommodative and disparity conditions.

Graph-Theory-Based Degree Centrality Combined with Machine Learning Algorithms Can Predict Response to Treatment with Antipsychotic Medications in Patients with First-Episode Schizophrenia

Objectives Schizophrenia (SCZ) is associated with disrupted functional brain connectivity, and antipsychotic medications are the primary and most commonly used treatment for schizophrenia. However, not all patients respond to antipsychotic medications. Methods The study is aimed at investigating whether the graph-theory-based degree centrality (DC), derived from resting-state functional MRI (rs-fMRI), can predict the treatment outcomes. rs-fMRI data from 38 SCZ patients were collected and compared with findings from 38 age- and gender-matched healthy controls (HCs). The patients were treated with antipsychotic medications for 16 weeks before undergoing a second rs-fMRI scan. DC data were processed using DPABI and SPM12 software. Results SCZ patients at baseline showed increased DC in the frontal and temporal gyrus, anterior cingulate cortex, and precuneus and reduced DC in bilateral subcortical gray matter structures. However, those abnormalities showed a clear renormalization after antipsychotic medication treatments. Support vector machine analysis using leave-one-out cross-validation achieved a correct classification rate of 84.2% (sensitivity 78.9%, specificity 89.5%, and area under the receiver operating characteristic curve (AUC) 0.925) for differentiating effective subjects from ineffective subjects. Brain areas that contributed most to the classification model were mainly located within the bilateral putamen, left inferior frontal gyrus, left middle occipital cortex, bilateral middle frontal gyrus, left cerebellum, left medial frontal gyrus, left inferior temporal gyrus, and left angular. Furthermore, the DC change within the bilateral putamen is negatively correlated with the symptom improvements after treatment. Conclusions Our study confirmed that graph-theory-based measures, combined with machine-learning algorithms, can provide crucial insights into pathophysiological mechanisms and the effectiveness of antipsychotic medications.

Working memory updating in individuals with bipolar and unipolar depression: fMRI study

Understanding neurobiological characteristics of cognitive dysfunction in distinct psychiatric disorders remains challenging. In this secondary data analysis, we examined neurobiological differences in brain response during working memory updating among individuals with bipolar disorder (BD), those with unipolar depression (UD), and healthy controls (HC). Individuals between 18–45 years of age with BD (n = 100), UD (n = 109), and HC (n = 172) were scanned using fMRI while performing 0-back (easy) and 2-back (difficult) tasks with letters as the stimuli and happy, fearful, or neutral faces as distractors. The 2(n-back) × 3(groups) × 3(distractors) ANCOVA examined reaction time (RT), accuracy, and brain activation during the task. HC showed more accurate and faster responses than individuals with BD and UD. Difficulty-related activation in the prefrontal, posterior parietal, paracingulate cortices, striatal, lateral occipital, precuneus, and thalamic regions differed among groups. Individuals with BD showed significantly lower difficulty-related activation differences in the left lateral occipital and the right paracingulate cortices than those with UD. In individuals with BD, greater difficulty-related worsening in accuracy was associated with smaller activity changes in the right precuneus, while greater difficulty-related slowing in RT was associated with smaller activity changes in the prefrontal, frontal opercular, paracingulate, posterior parietal, and lateral occipital cortices. Measures of current depression and mania did not correlate with the difficulty-related brain activation differences in either group. Our findings suggest that the alterations in the working memory circuitry may be a trait characteristic of reduced working memory capacity in mood disorders. Aberrant patterns of activation in the left lateral occipital and paracingulate cortices may be specific to BD.

Neural substrates of saccadic adaptation: Plastic changes versus error processing and forward versus backward learning

Previous behavioral, clinical, and neuroimaging studies suggest that the neural substrates of adaptation of saccadic eye movements involve, beyond the central role of the cerebellum, several, still incompletely determined, cortical areas. Furthermore, no neuroimaging study has yet tackled the differences between saccade lengthening (“forward adaptation”) and shortening (“backward adaptation”) and neither between their two main components, i.e. error processing and oculomotor changes. The present fMRI study was designed to fill these gaps. Blood-oxygen-level-dependent (BOLD) signal and eye movements of 24 healthy volunteers were acquired while performing reactive saccades under 4 conditions repeated in short blocks of 16 trials: systematic target jump during the saccade and in the saccade direction (forward: FW) or in the opposite direction (backward: BW), randomly directed FW or BW target jump during the saccade (random: RND) and no intra-saccadic target jump (stationary: STA). BOLD signals were analyzed both through general linear model (GLM) approaches applied at the whole-brain level and through sensitive Multi-Variate Pattern Analyses (MVPA) applied to 34 regions of interest (ROIs) identified from independent 'Saccade Localizer’ functional data. Oculomotor data were consistent with successful induction of forward and backward adaptation in FW and BW blocks, respectively. The different analyses of voxel activation patterns (MVPAs) disclosed the involvement of 1) a set of ROIs specifically related to adaptation in the right occipital cortex, right and left MT/MST, right FEF and right pallidum; 2) several ROIs specifically involved in error signal processing in the left occipital cortex, left PEF, left precuneus, Medial Cingulate cortex (MCC), left inferior and right superior cerebellum; 3) ROIs specific to the direction of adaptation in the occipital cortex and MT/MST (left and right hemispheres for FW and BW, respectively) and in the pallidum of the right hemisphere (FW). The involvement of the left PEF and of the (left and right) occipital cortex were further supported and qualified by the whole brain GLM analysis: clusters of increased activity were found in PEF for the RND versus STA contrast (related to error processing) and in the left (right) occipital cortex for the FW (BW) versus STA contrasts [related to the FW (BW) direction of error and/or adaptation]. The present study both adds complementary data to the growing literature supporting a role of the cerebral cortex in saccadic adaptation through feedback and feedforward relationships with the cerebellum and provides the basis for improving conceptual frameworks of oculomotor plasticity and of its link with spatial cognition.

Clinical MRI morphological analysis of functional seizures compared to seizure-naïve and psychiatric controls

PurposeFunctional seizures (FS), also known as psychogenic nonepileptic seizures (PNES), are physical manifestations of acute or chronic psychological distress. Functional and structural neuroimaging have identified objective signs of this disorder. We evaluated whether magnetic resonance imaging (MRI) morphometry differed between patients with FS and clinically relevant comparison populations. MethodsQuality-screened clinical-grade MRIs were acquired from 666 patients from 2006 to 2020. Morphometric features were quantified with FreeSurfer v6. Mixed-effects linear regression compared the volume, thickness, and surface area within 201 regions-of-interest for 90 patients with FS, compared to seizure-naïve patients with depression (n = 243), anxiety (n = 68), and obsessive–compulsive disorder (OCD, n = 41), respectively, and to other seizure-naïve controls with similar quality MRIs, accounting for the influence of multiple confounds including depression and anxiety based on chart review. These comparison populations were obtained through review of clinical records plus research studies obtained on similar scanners. ResultsAfter Bonferroni–Holm correction, patients with FS compared with seizure-naïve controls exhibited thinner bilateral superior temporal cortex (left 0.053 mm, p = 0.014; right 0.071 mm, p = 0.00006), thicker left lateral occipital cortex (0.052 mm, p = 0.0035), and greater left cerebellar white-matter volume (1085 mm3, p = 0.0065). These findings were not accounted for by lower MRI quality in patients with FS. ConclusionsThese results reinforce prior indications of structural neuroimaging correlates of FS and, in particular, distinguish brain morphology in FS from that in depression, anxiety, and OCD. Future work may entail comparisons with other psychiatric disorders including bipolar and schizophrenia, as well as exploration of brain structural heterogeneity within FS.

Effect of Moxibustion Treatment on Degree Centrality in Patients With Mild Cognitive Impairment: A Resting-State Functional Magnetic Resonance Imaging Study

BackgroundMild cognitive impairment (MCI) is a common neurological disorder. Moxibustion has been shown to be effective in treating MCI, but its therapeutic mechanisms still remain unclear. This study mainly aimed to investigate the modulation effect of moxibustion treatment for patients with MCI by functional magnetic resonance imaging (fMRI).MethodsA total of 47 patients with MCI and 30 healthy controls (HCs) participated in resting-state fMRI imaging (rs-fMRI) scans. Patients with MCI were randomly divided into true moxibustion group (TRUE, n = 30) and sham moxibustion group (SHAM, n = 17). The degree centrality (DC) approach was applied to distinguish altered brain functions. Correlation analysis was then performed to examine the relationships between the neuroimaging findings and clinical symptoms.ResultsCompared with HCs, patients with MCI mainly showed decreased DC in the left middle frontal cortex (MFC) and bilateral middle cingulate cortex (MCC). After moxibustion treatment, the SHAM group had no significant DC findings, while TRUE group mainly showed significant increased DC in the bilateral MFC and MCC, as well as decreased DC in the left middle occipital cortex (MOC). Repeated measures analysis of variance (ANOVA) showed significant interactions between the two groups of patients with MCI. In addition, the higher Mini-Mental State Examination (MMSE) score was significantly positively correlated with increased DC in the right MFC and left MCC after moxibustion treatment.ConclusionOur findings demonstrate that the potential value of moxibustion treatment on MCI, which adds new insights into the popular view that moxibustion treatment may slow cognitive decline in patients with MCI.

Catheter‐associated air embolism of the brain in a hospitalised horse

AbstractAn 8‐year‐old, approximately 590 kg Belgian draft cross gelding was anaesthetised for tenoscopy and repair of a tendon sheath laceration. The horse remained hospitalised for several days. During post‐operative hospitalisation, the jugular catheter accidentally became disconnected from the extension set. The next day, the horse was blind bilaterally and circling to the left. Elevated cardiac troponin with mild tachycardia was also noted. The horse was treated supportively, but neurologic signs persisted, and after 3 weeks of no improvement humane euthanasia was elected. The most significant finding on gross postmortem examination was generalised cerebral oedema and gross malacia and haemorrhage of the left occipital cortex. Histopathology revealed regionally extensive grey and white matter necrosis in the left and right occipital cortices, consistent with an infarctive pathogenesis. The history and postmortem examination findings are compatible with air emboli in the brain. This is a rare but serious complication of intravenous catheter use in horses.

Brain responses in aggression-prone individuals: A systematic review and meta-analysis of functional magnetic resonance imaging (fMRI) studies of anger- and aggression-eliciting tasks

Reactive aggression in response to perceived threat or provocation is part of humans' adaptive behavioral repertoire. However, high levels of aggression can lead to the violation of social and legal norms. Understanding brain function in individuals with high levels of aggression as they process anger- and aggression-eliciting stimuli is critical for refining explanatory models of aggression and thereby improving interventions. Three neurobiological models of reactive aggression – the limbic hyperactivity, prefrontal hypoactivity, and dysregulated limbic-prefrontal connectivity models – have been proposed. However, these models are based on neuroimaging studies involving mainly non-aggressive individuals, leaving it unclear which model best describes brain function in those with a history of aggression.We conducted a systematic literature search (PubMed and Psycinfo) and Multilevel Kernel Density meta-analysis (MKDA) of nine functional magnetic resonance imaging (fMRI) studies (eight included in the between-group analysis [i.e., aggression vs. control groups], five in the within-group analysis). Studies examined brain responses to tasks putatively eliciting anger and aggression in individuals with a history of aggression alone and relative to controls.Individuals with a history of aggression exhibited greater activity in the superior temporal gyrus and in regions comprising the cognitive control and default mode networks (right posterior cingulate cortex, precentral gyrus, precuneus, right inferior frontal gyrus) during reactive aggression relative to baseline conditions. Compared to controls, individuals with a history of aggression exhibited increased activity in limbic regions (left hippocampus, left amygdala, left parahippocampal gyrus) and temporal regions (superior, middle, inferior temporal gyrus), and reduced activity in occipital regions (left occipital cortex, left calcarine cortex).These findings lend support to the limbic hyperactivity model in individuals with a history of aggression, and further indicate altered temporal and occipital activity in anger- and aggression-eliciting conditions involving face and speech processing.

Gray Matter Network Associated With Attention in Children With Attention Deficit Hyperactivity Disorder.

BackgroundAttention deficit hyperactivity disorder (ADHD) is one of the most prevalent childhood-onset neurodevelopmental disorders; however, the underlying neural mechanisms for the inattention symptom remain elusive for children with ADHD. At present, the majority of studies have analyzed the structural MRI (sMRI) with the univariate method, which fails to demonstrate the interregional covarying relationship of gray matter (GM) volumes among brain regions. The scaled subprofile model of principal component analysis (SSM-PCA) is a multivariate method, which can detect more robust brain-behavioral phenotype association compared to the univariate analysis method. This study aims to identify the GM network associated with attention in children with ADHD by applying SSM-PCA to the sMRI.MethodsThe sMRI of 209 children with ADHD and 209 typically developing controls (TDCs) aged 7–14 years from the ADHD-200 dataset was used for anatomical computation, and the GM volume in each brain region was acquired. Then, SSM-PCA was applied to the GM volumes of all the subjects to capture the GM network of children with ADHD (i.e., ADHD-related pattern). The relationship between the expression of ADHD-related pattern and inattention symptom was further investigated. Finally, the influence of sample size on the analysis of this study was explored.ResultsThe ADHD-related pattern mainly included putamen, pallium, caudate, thalamus, right accumbens, superior/middle/inferior frontal cortex, superior occipital cortex, superior parietal cortex, and left middle occipital cortex. In addition, the expression of the ADHD-related pattern was related to inattention scores measured by the Conners’ Parent Rating Scale long version (CPRS-LV; r = 0.25, p = 0.0004) and the DuPaul ADHD Rating Scale IV (ADHD-RS; r = 0.18, p = 0.03). Finally, we found that when the sample size was 252, the results of ADHD-related pattern were relatively reliable. Similarly, the sample size needed to be 162 when exploring the relationship between ADHD-related pattern and behavioral indicator measured by CPRS-LV.ConclusionWe captured a GM network associated with attention in children with ADHD, which is different from that in adolescents and adults with ADHD. Our findings may shed light on the diverse neural mechanisms of inattention and provide treatment targets for children with ADHD.

Cerebrospinal Fluid sTREM2 Has Paradoxical Association with Brain Structural Damage Rate in Early- and Late-Stage Alzheimer's Disease.

Recently it has been proposed that microglial response has a stage-dependent effect on the progression of Alzheimer's disease (AD). Cerebrospinal fluid (CSF) sTREM2 has emerged as a promising microglial activation marker. To test the stage-dependent role of microglia by studying the association between baseline sTREM2 and dynamic brain structural changes in AD and mild cognitive impairment (MCI) patients. 22 amyloid-β-positive (A+) and tau-positive (T+) AD and 24 A+T+MCI patients were identified from the Alzheimer's Disease Neuroimaging Initiative. The patients had baseline CSF amyloid-β, phosphorylated-tau, and sTREM2, and were followed up for at least one year by T1-weighted and diffusion tensor imaging scans. Gray matter volumes and white matter microstructural integrity were evaluated. Linear mixed models were applied to analyze how baseline sTREM2 may influence the rate of brain structural changes while adjusting for the effects of age, APOE4 status, and the CSF core markers. In A+T+AD patients, baseline CSF sTREM2 was associated with faster mean diffusivity increase in the bilateral posterior corona radiata and right superior longitudinal fasciculus. In A+T+MCI patients, baseline CSF sTREM2 was associated slower gray matter volumetric loss in parahippocampal gyrus, left fusiform cortex, left middle temporal gyrus, and left lateral occipital cortex. Baseline CSF sTREM2 also had a protective effect against mean diffusivity increase in right inferior fronto-occipital fasciculus, left superior longitudinal fasciculus, left forceps minor, and left uncinate fasciculus. Microglial activation at early stage might have a protective effect against neurodegeneration, while at late stage it might facilitate AD. Future efforts on modulating microglial activation could be promising, given a carefully selected time window for intervention.

Changes in working memory brain activity and task-based connectivity after long-duration spaceflight.

We studied the longitudinal effects of approximately 6 months of spaceflight on brain activity and task-based connectivity during a spatial working memory (SWM) task. We further investigated whether any brain changes correlated with changes in SWM performance from pre- to post-flight. Brain activity was measured using functional magnetic resonance imaging while astronauts (n= 15) performed a SWM task. Data were collected twice pre-flight and 4 times post-flight. No significant effects on SWM performance or brain activity were found due to spaceflight; however, significant pre- to post-flight changes in brain connectivity were evident. Superior occipital gyrus showed pre- to post-flight reductions in task-based connectivity with the rest of the brain. There was also decreased connectivity between the left middle occipital gyrus and the left parahippocampal gyrus, left cerebellum, and left lateral occipital cortex during SWM performance. These results may reflect increased visual network modularity with spaceflight. Further, increased visual and visuomotor connectivity were correlated with improved SWM performance from pre- to post-flight, while decreased visual and visual-frontal cortical connectivity were associated with poorer performance post-flight. These results suggest that while SWM performance remains consistent from pre- to post-flight, underlying changes in connectivity among supporting networks suggest both disruptive and compensatory alterations due to spaceflight.

Brain Structural and Functional Dissociated Patterns in Degenerative Cervical Myelopathy: A Case-Controlled Retrospective Resting-State fMRI Study.

BackgroundPrevious studies have shown the whole-brain global functional connectivity density (gFCD) and gray matter volume (GMV) alterations in patients with degenerative cervical myelopathy (DCM). However, no study aimed to investigate the associations between the spatial patterns of GMV and gFCD alterations in patients with DCM.MethodsStructural data and resting-state functional MRI data of 35 DCM patients and 35 matched healthy controls were collected to assess their gFCD and GMV and investigate gFCD and GMV alterations in patients with DCM and their spatial pattern associations.ResultsIn our current study, significant gFCD and GMV differences were observed in some regions of the visual system, sensorimotor cortices, and cerebellum between patients with DCM and healthy controls. In our findings, decreased gFCD was found in areas primarily located at the sensorimotor cortices, while increased gFCD was observed primarily within areas located at the visual system and cerebellum. Decreased GMV was seen in the left thalamus, bilateral supplementary motor area (SMA), and left inferior occipital cortices in patients with DCM, while increased GMV was observed in the cerebellum.ConclusionOur findings suggest that structural and functional alterations independently contributed to the neuropathology of DCM. However, longitudinal studies are still needed to further illustrate the associations between structural deficits and functional alterations underlying the onset of brain abnormalities as DCM develops.

Neuroanatomical foundations of delayed reward discounting decision making II: Evaluation of sulcal morphology and fractal dimensionality

Delayed reward discounting (DRD) is a form of decision-making reflecting valuation of smaller immediate rewards versus larger delayed rewards, and high DRD has been linked to several health behaviors, including substance use disorders, attention-deficit/hyperactivity disorder, and obesity. Elucidating the underlying neuroanatomical factors may offer important insights into the etiology of these conditions. We used structural MRI scans of 1038 Human Connectome Project participants (Mage = 28.86, 54.7% female) to explore two novel measures of neuroanatomy related to DRD: 1) sulcal morphology (SM; depth and width) and 2) fractal dimensionality (FD), or cortical morphometric complexity, of parcellated cortical and subcortical regions. To ascertain unique contributions to DRD preferences, indicators that displayed significant partial correlations with DRD after family-wise error correction were entered into iterative mixed-effect models guided by the association magnitude. When considering only SM indicators, the depth of the right inferior and width of the left central sulci were uniquely associated with DRD preferences. When considering only FD indicators, the FD of the left middle temporal gyrus, right lateral orbitofrontal cortex, and left lateral occipital and entorhinal cortices uniquely contributed DRD. When considering SM and FD indicators simultaneously, the right inferior frontal sulcus depth and left central sulcus width; and the FD of the left middle temporal gyrus, lateral occipital cortex and entorhinal cortex were uniquely associated with DRD. These results implicate SM and FD as features of the brain that underlie variation in the DRD decision-making phenotype and as promising candidates for understanding DRD as a biobehavioral disease process.

RELN rs7341475 Associates with Brain Structure in Japanese Healthy Females

Although temperament has been regarded as an innate aspect of human personality, its association with proteins involved in embryonic development is unclear. Reelin, encoded by RELN, plays an important role in brain development. Herein, we investigated the association between the RELN rs7341475 (G/A) single nucleotide polymorphism, detected as a female-specific risk factor for schizophrenia, brain structure, and temperament to elucidate the role of RELN in the development of human personality. In this study, 1580 healthy young Japanese adults were genotyped for RELN rs7341475 and completed the Temperament and Character Inventory. Whole-brain analysis of covariance was conducted to investigate differences between genotypes in regional gray matter volume (rGMV) and cortical morphology. Additionally, multiple regression analysis was performed to examine the association of four temperaments with rGMV. Those statistical analyses were performed separately for males and females. Individuals with G/G homozygosity showed significantly greater rGMV in several areas of the brain, particularly the bilateral cingulate and temporal gyrus, as well as a larger value of fractal dimension in the left lateral occipital cortex. Furthermore, of the four temperaments, the novelty seeking was significantly and positively associated with rGMV in the right superior temporal gyrus, partially overlapping with areas where differences between the rs7341475 genotypes were detected. The above findings were detected only in females, but not in males. This is the first study to demonstrate the contribution of RELN rs7341475 to differences in brain structure in Japanese females, which may indicate vulnerability to schizophrenia and variations in human personality.

Systemic Phaeohyphomycosis in a Dog Caused by Cladophialophora bantiana

Background: Cladophialophora bantiana is a dematiaceous fungus that causes phaeohyphomycosis, a generic term used to describe a variety of unusual mycoses caused by fungi that have melanin in their cell wall. C. bantiana targets the central nervous system, commonly causing localized brain infections that may result in disseminated infections. In Brazil, minimal phaeohyphomycosis data are available, and information about C. bantiana infections in animals, especially canines, is scarce. Thus, the aim of this study was to describe the clinical and pathological aspects of systemic phaeohyphomycosis caused by C. bantiana in a dog.Case: A 1-year-old female Pit Bull presented with weight loss, reduced appetite, and a history of cutaneous lesions on the right thoracic limb; however, clinical evolution was not reported. The dog had reportedly given birth recently. Physical examination revealed thinness, pale ocular and oral mucosa, submandibular lymph nodes, and enlarged popliteal lymph nodes. The animal died after convulsive crises during hospitalization. At necropsy, white-yellowish multifocal nodules were observed in the liver and right kidney. The brain featured left cerebral hemisphere asymmetry with blood vessel congestion in the leptomeninges and an irregular brownish focal area on the surface of the right occipital cortex. Cross-sections of the formalin-fixed brain exhibited compression of the left lateral ventricle and the presence of grayish and friable multifocal areas in the gray matter of the left parietal and right occipital cortices. Fragments of the lesions were collected for histopathological and microbiological examination. Histologically, the lesions were similar, characterized by hepatitis, nephritis, and granulomatous and necrotizing meningoencephalitis, multifocal to coalescing, accentuated, chronic, and associated with numerous pigmented fungi. Fontana-Masson–stained fungi exhibited a strong black color. In cleared and unstained histological slides, brownish pigmentation was observed in the cytoplasm and walls of the fungi. C. bantiana was identified via microbiological cultivation.Discussion: A diagnosis of phaeohyphomycosis caused by C. bantiana was made based on the characteristic morphology of the microscopic lesions and confirmed via isolation in microbiological culture. As numerous species cause phaeohyphomycosis, specific confirmation of the etiologic agent using several diagnostic techniques is necessary. In histopathological examinations, pigmented fungal organisms are easily seen among lesions. However, in some cases, the pigment is not apparent in the tissues. FM staining is necessary to demonstrate the presence of the melanin in fungi. As in most phaeohyphomycosis cases, it was not possible to determine the primary portal of entry. However, the lesion on the right thoracic limb probably favored the penetration of the agent. In addition to cerebral lesions, severe lesions in the hepatic and renal parenchyma were observed, which are characteristic of systemic mycosis. Infection and clinical diseases are usually associated with immunocompromised; here, the gestation period may have had an immunosuppressive effect, favoring the proliferation and dissemination of the agent. It was concluded that phaeohyphomycosis caused by C. bantiana produced severe systemic lesions in the brain and organs of the abdominal cavity. Although uncommon, phaeohyphomycosis caused by Cladophialophora bantiana should be included as a differential diagnosis for other canine diseases that present with similar clinical symptoms.Keywords: canine, fungal diseases, dematiaceous fungi, Cladosporium trichoides, Xylohypha bantiana, melanin, Fontana-Masson

Resting-state functional connectivity indicators of risk and resilience for self-harm in adolescent bipolar disorder.

Suicide is the second leading cause of death in all youth and among adults with bipolar disorder (BD). The risk of suicide in BD is among the highest of all psychiatric conditions. Self-harm, including suicide attempts and non-suicidal self-injury, is a leading risk factor for suicide. Neuroimaging studies suggest reward circuits are implicated in both BD and self-harm; however, studies have yet to examine self-harm related resting-state functional connectivity (rsFC) phenotypes within adolescent BD. Resting-state fMRI data were analyzed for 141 adolescents, ages 13-20 years, including 38 with BD and lifetime self-harm (BDSH+), 33 with BD and no self-harm (BDSH-), and 70 healthy controls (HC). The dorsolateral prefrontal cortex (dlPFC), orbitofrontal cortex (OFC) and amygdala were examined as regions of interest in seed-to-voxel analyses. A general linear model was used to explore the bivariate correlations for each seed. BDSH- had increased positive rsFC between the left amygdala and left lateral occipital cortex, and between the right dlPFC and right frontal pole, and increased negative rsFC between the left amygdala and left superior frontal gyrus compared to BDSH+ and HC. BDSH+ had increased positive rsFC of the right OFC with the precuneus and left paracingulate gyrus compared to BDSH- and HC. This study provides preliminary evidence of altered reward-related rsFC in relation to self-harm in adolescents with BD. Between-group differences conveyed a combination of putative risk and resilience connectivity patterns. Future studies are warranted to evaluate changes in rsFC in response to treatment and related changes in self-harm.

Correlation of visual area with tremor improvement after MRgFUS thalamotomy in Parkinson's disease.

MRI-guided focused ultrasound (MRgFUS) thalamotomy is a novel and minimally invasive alternative for medication-refractory tremor in Parkinson's disease (PD). However, the impact of MRgFUS thalamotomy on spontaneous neuronal activity in PD remains unclear. The purpose of the current study was to evaluate the effects of MRgFUS thalamotomy on local fluctuations in neuronal activity as measured by the fractional amplitude of low-frequency fluctuations (fALFF) in patients with PD. Participants with PD undergoing MRgFUS thalamotomy were recruited. Tremor scores were assessed before and 3 and 12 months after treatment using the Clinical Rating Scale for Tremor. MRI data were collected before and 1 day, 1 week, 1 month, 3 months, and 12 months after thalamotomy. The fALFF was calculated. A whole-brain voxel-wise paired t-test was used to identify significant changes in fALFF at 12 months after treatment compared to baseline. Then fALFF in the regions with significant differences were extracted from fALFF maps of patients for further one-way repeated-measures ANOVA to investigate its dynamic alterations. The association between fALFF changes induced by thalamotomy and tremor improvement were evaluated using the nonparametric Spearman rank test. Nine participants with PD (mean age ± SD 64.7 ± 6.1 years, 8 males) were evaluated. Voxel-based analysis showed that fALFF in the left occipital cortex (Brodmann area 17 [BA17]) significantly decreased at 12 months after thalamotomy compared to baseline (voxel p < 0.001, cluster p < 0.05 family-wise error [FWE] corrected). At baseline, fALFF in the left occipital BA17 in patients was elevated compared with that in 9 age- and gender-matched healthy subjects (p < 0.05). Longitudinal analysis displayed the dynamic changes of fALFF in this region (F (5,40) = 3.61, p = 0.009). There was a significant positive correlation between the falling trend in fALFF in the left occipital BA17 and hand tremor improvement after treatment over 3 time points (Spearman's rho = 0.44, p = 0.02). The present study investigated the impact of MRgFUS ventral intermediate nucleus thalamotomy on spontaneous neural activity in medication-refractory tremor-dominant PD. The visual area is, for the first time, reported as relevant to tremor improvement in PD after MRgFUS thalamotomy, suggesting a distant effect of MRgFUS thalamotomy and the involvement of specific visuomotor networks in tremor control in PD.

Developmental abnormalities of structural covariance networks of cortical thickness and surface area in autistic infants within the first 2years.

Converging evidence supports that a collection of brain regions is functionally or anatomically abnormal in autistic subjects. Structural covariance networks (SCNs) representing patterns of coordinated regional maturation are widely used to study abnormalities associated with neurodisorders. However, the possible developmental changes of SCNs in autistic individuals during the first 2 postnatal years, which features dynamic development and can potentially serve as biomarkers, remain unexplored. To fill this gap, for the first time, SCNs of cortical thickness and surface area were constructed and investigated in infants at high familial risk for autism and typically developing infants in this study. Group differences of SCNs emerge at 12months of age in surface area. By 24months of age, the autism group shows significantly increased integration, decreased segregation, and decreased small-worldness, compared with controls. The SCNs of surface area are deteriorated and shifted toward randomness in autistic infants. The abnormal brain regions changed during development, and the group differences of the left lateral occipital cortex become more prominent with age. These results indicate that autism has more significant influences on coordinated development of surface area than that of cortical thickness and the occipital cortex maybe an important biomarker of autism during infancy.