Functional Topography Research Articles

Drivers of aboveground biomass shift with forest stratum in temperate forest of North China

A better understanding of the underlying ecological mechanisms of diversity-biomass relationships in forest layers (i.e., overstory and understory) is critical to understand the importance of vertical stratification to the functioning of forest ecosystems. However, it is not clear how multiple abiotic (i.e., climate and geography) and biological (i.e., biodiversity, functional characteristics, and stand structural complexity) factors simultaneously determine the aboveground biomass (AGB) of each individual forest stratum. We used data on 156,270 trees from 1986 plots in North China to explore the relationships among biological diversity, plant functional traits, stand structure, climate and topography on variation in AGB of each stratum. The results showed that different biological factors determined the AGB of overstory and understory, and thus indicating different underlying ecological mechanisms in temperate forests. The effects of forest biodiversity on AGB were only significant in understory stratum. In the overstory of the forest, forests with high tree-size dimension inequality and high dominant tree height had larger AGB, hence mass ratio effect and stand structure complexity were the main ecological mechanisms for high biomass. In understory, diversity and overstory attributes were the main factors affecting biomass. Tree height and AGB of the overstory reduced the AGB of the understory layer. In consequence overstory attributes and niche complementation were the main ecological mechanisms in the understory. The overstory exerted influence on the understory through resource quantity and resource heterogeneity. Our findings have important implications for carbon management, enhancement of forest functions and sustainable forest management in temperate forests.

A method to establish functional vagus nerve topography from electro-neurographic spontaneous activity

Bioelectronic medicine is an emerging approach to treat many types of diseases via electrical stimulation of the autonomic nervous system (ANS). Because the vagus nerve (VN) is one of the most important nerves controlling several ANS functions, stimulation protocols based on knowledge of the functional organization of the VN are particularly interesting. Here, we proposed a method to localize different physiological VN functions by exploiting electro-neurographic signals recorded during spontaneous VN fibers activity. We tested our method on a realistic human cervical VN model geometry implanted via epineural or intraneural electrodes. We considered in silico ground truth scenarios of functional topography generated via different functional neural fibers activities covered by background noise. Our method accurately estimated the underlying functional VN topography by outperforming state-of-the-art methods. Our work paves the way for development of spatially selective stimulation protocols targeting multiple VN bodily functions.

Columnar Lesions in Barrel Cortex Persistently Degrade Object Location Discrimination Performance.

Primary sensory cortices display functional topography, suggesting that even small cortical volumes may underpin perception of specific stimuli. Traditional loss-of-function approaches have a relatively large radius of effect (>1 mm), and few studies track recovery following loss-of-function perturbations. Consequently, the behavioral necessity of smaller cortical volumes remains unclear. In the mouse primary vibrissal somatosensory cortex (vS1), "barrels" with a radius of ∼150 μm receive input predominantly from a single whisker, partitioning vS1 into a topographic map of well defined columns. Here, we train animals implanted with a cranial window over vS1 to perform single-whisker perceptual tasks. We then use high-power laser exposure centered on the barrel representing the spared whisker to produce lesions with a typical volume of one to two barrels. These columnar-scale lesions impair performance in an object location discrimination task for multiple days without disrupting vibrissal kinematics. Animals with degraded location discrimination performance can immediately perform a whisker touch detection task with high accuracy. Animals trained de novo on both simple and complex whisker touch detection tasks showed no permanent behavioral deficits following columnar-scale lesions. Thus, columnar-scale lesions permanently degrade performance in object location discrimination tasks.

Evaluation of the posterior insular cortex involvement in anxiogenic response to emotional stress in male rats: Functional topography along the rostrocaudal axis

The insular cortex (IC) is engaged in behavioral and physiological responses to emotional stress. Control of physiological functions and behavioral responses has been reported to occur in a site-specific manner along the rostrocaudal axis of the IC. However, a functional topography of the IC regulation of anxiogenic responses caused by stress has never been evaluated. Therefore, we investigated the role of rostrocaudal subregions in the posterior IC in anxiogenic-like effect caused by exposure to acute restraint stress in male rats. For this, rats received bilateral microinjection of the non-selective synaptic inhibitor CoCl2 or vehicle into either the rostral, intermediate or caudal portions of the posterior IC before exposure to acute restraint stress. Then, behavior in the elevated plus maze (EPM) was evaluated immediately after restraint stress. The behavior of non-stressed animals in the EPM was also investigated. We observed that acute restraint stress decreased the exploration of the EPM open arms in animals treated with vehicle in all regions of the posterior IC, thus indicating an anxiogenic-like effect. The avoidance of the EPM open arms was completely inhibited in animals subjected to microinjection of CoCl2 into the intermediate posterior IC. Nevertheless, the same pharmacological treatment into either the rostral or caudal subregions of the posterior IC did not affect the restraint-evoked behavioral changes in the EPM. Taken together, these results suggest that regulation of anxiogenic-like effect to emotional stress along the rostrocaudal axis of the posterior IC might occur in a site-specific manner, indicating a role of the intermediate subregion.

Functional orderly topography of brain networks associated with gene expression heterogeneity

The human cerebral cortex is vastly expanded relative to nonhuman primates and rodents, leading to a functional orderly topography of brain networks. Here, we show that functional topography may be associated with gene expression heterogeneity. The neocortex exhibits greater heterogeneity in gene expression, with a lower expression of housekeeping genes, a longer mean path length, fewer clusters, and a lower degree of ordering in networks than archicortical and subcortical areas in human, rhesus macaque, and mouse brains. In particular, the cerebellar cortex displays greater heterogeneity in gene expression than cerebellar deep nuclei in the human brain, but not in the mouse brain, corresponding to the emergence of novel functions in the human cerebellar cortex. Moreover, the cortical areas with greater heterogeneity, primarily located in the multimodal association cortex, tend to express genes with higher evolutionary rates and exhibit a higher degree of functional connectivity measured by resting-state fMRI, implying that such a spatial distribution of gene expression may be shaped by evolution and is favourable for the specialization of higher cognitive functions. Together, the cross-species imaging and genetic findings may provide convergent evidence to support the association between the orderly topography of brain function networks and gene expression.

Characteristics of cognitive function in patients with cerebellar infarction and its association with lesion location.

Objective: This study aimed to explore the characteristics of cognitive function in patients with cerebellar infarction and its association with lesion location.Methods: Forty-five patients with isolated cerebellar infarction were collected in the Department of Neurology, Beijing Tiantan Hospital. Thirty healthy controls were recruited matched by age and education. Global cognitive function was evaluated by using Addenbrooke’s Cognitive Examination version III (ACE-III). An extensive neuropsychological assessment battery was also tested to evaluate the characteristics of each cognitive domain. 3D slicer software was used to draw the lesion, and evaluate the lesions’ volume, side, and location. Group analysis was used to compare the differences in cognitive performance between patients and healthy controls, and patients with left and right cerebellar hemisphere infarction. Spearman analysis was used to explore the correlation between cognitive function and lesion volume. We also subdivided each patient’s lesions according to the cerebellar atlas to identify the specific cerebellar location related to cognitive decline.Results: Patients with cerebellar infarction had a lower ACE-III score compared with the healthy group (87.9 ± 6.2 vs. 93.7 ± 2.9, p < 0.001), and 22 (48.9%) patients were diagnosed with cognitive impairment. The z-transformed score of attention and executive function in the patients’ group was −0.9 ± 1.4 and −0.8 ± 1.0 respectively, with 19 (43.2%) and 23 (56.4%) patients impaired. Compared with healthy controls, the relative risk ratio with 95% confidence interval (CI) for impairment in attention and executive function were 3.24 (1.22–8.57) and 3.39 (1.45–7.89). However, only 10 (22.1%) patients showed impairment in more than two cognitive domains. Compared with the left lesion group, patients with right cerebellar infarction showed significantly impaired executive function (−1.1 ± 0.3 vs. −0.5 ± 0.2, p = 0.01). And the cerebellar posterior lobe regions, especially lobules VI, VIII, and IX, were explored to have lower cognitive performance. Furthermore, lesion volume was identified to be associated with the ACE-III score (r = −0.37, p = 0.04).Conclusion: We identified that cerebellar involvement in cognition, especially in attention processing and executive function. Cerebellar right-sided lateralization of cognition and functional topography were also revealed in the current study.

S423 Association Between Defective Secondary Peristalsis Detected by Functional Lumen Imaging Probe Topography (FLIP) and GERD

Introduction: Esophageal secondary peristalsis is a defense mechanism against GERD by clearance of refluxate. When absent or defective, it may lead to increased esophageal acid exposure time (AET). Functional lumen imaging probe topography (FLIP) allows assessment of secondary peristalsis induced by volumetric distension. Aim: evaluate the association between secondary peristalsis and GERD. Methods: We included patients with esophageal symptoms who underwent FLIP topography and reflux monitoring (wireless pH or catheter-based pH-impedance) while off PPI ≥7 days, high-resolution esophageal manometry (HRM) findings (LES pressure, ineffective esophageal motility , absent contractility) were added for secondary analysis when available. Exclusion criteria: achalasia, prior gastroesophageal surgery, Botox injection within 6 months of FLIP and reflux study. Abnormal AET on reflux monitoring was defined as % time pH< 4 greater than 4%. FLIP was performed with a 16 cm balloon during propofol-sedated endoscopy; peristaltic response was assessed at 30-40-50-60 ml and classified as repetitive antegrade contractions (RACs), borderline contractile response, repetitive retrograde contractions (RRCs), impaired, absent, and spastic reactive. EGJ distensibility index (DI) was calculated at 60ml. Secondary peristalsis was considered intact if RACs seen at any volume, impaired otherwise. Those with borderline contractility but no RACs were excluded from analysis.. We assessed the association between FLIP and HRM findings and GERD by t test and chi square. Results: 37 patients included (23, 62% female), mean age 58.45 years, mean BMI 25.7. GERD present in 15 (40.5%). Mean esophageal AET was lower in patients with versus without intact peristalsis but significance not reached (5.8% vs 3.0%, p=0.058). The proportion of patients with GERD was lower in patients with peristalsis versus without intact peristalsis but significance not reached (25% vs 40%, p=0.18). There was no association between GERD and DI or any HRM measures. Conclusion: Our data suggests that defective secondary peristalsis is more frequent in GERD patients and is thus and important contributing factor to reflux. Lack of significance may be due to small sample size and type II error, but a larger number of patients is needed to clarify this and data collection is ongoing.

Experimental analyses of surface treatment on titanium samples

The roughness of the dental implant surface will influence the behavior of osteoblastic cells regarding the spread, proliferation, differentiation and synthesis of proteins on the surface of titanium. Depending on its characteristics, roughness can be macro-, micro- and nano-roughness. Material and method. We achieved the obtaining of thin layers of biomaterials by the pulsed laser deposition method (PLD, Pulsed Laser Deposition) on the titanium samples and the deposition has been made by Spin coating method of a thin film based on hydroxyapatite, respectively hydroxyapatite-maleic copolymer, only on one side of the sample. Results. From a microscopic point of view, the qualities of bio-glass are remarkable. Thus, bio-glasses are amorphous materials and are successfully used as covering material for metallic and polymeric implants, to significantly increase their biocompatibility. Discussion. The biological properties of the materials for implants are of fundamental importance for the success of the treatments and they are reflected along with other characteristics of the implants, in the tissue reaction they cause under the conditions of their insertion in biological systems. Conclusion. Osseointegration could be impaired in people with diabetes, osteoporosis, with bone metabolism disorder where therapeutic success depends on the biomimetic and functional topography of the dental implant.

Personal experience in intramedullary lesions, in adults

Background: Intramedullary spinal cord lesions (IMSCL) although they are rare, it generates invasion and destruction of the spinal cord. Such lesions must be diagnosed as early as possible, some have histological and genetic aggressiveness, generating severe functional neurological damage.&#x0D; Objective: To identify the optimal strategy for diagnosis and treatment in IMSC, to improve prognosis.&#x0D; Methods: A retrospective clinical study from 2001 to 2021, was performed on 33 adult patients (18 women, 15 men), diagnosed with magnetic resonance imaging with IMSCT. The most common topography was: thoracic 27 cases disposed between T2-T12, cervical 6 cases disposed between C2-C6, lumbar 2 cases at L1-L2. The most frequent symptoms in my cases were: unilateral radicular pain related to the tumour topography or bilateral diffuse burning pain, especially during the night; back and neck stiffness; paresthesia, motor disturbances with an ASIA score of 2-4, and severe atrophy especially in cervical topography, ataxia, initial retention, impotence and later loss of bowel and bladder function with incontinence. All patients were operated by the same senior neurosurgeon with at least 6 months of follow-up postoperatively. For functional outcome, the most important predictors are the preoperative neurological grade, and the high-grade IMSCT generating recurrence and reoperations.&#x0D; Results: The patients addressed the clinic for pain and neurological deficits; the topography of the intramedullary lesion was confirmed by MRI native / with contrast, ultrasonography, and spinal arteriography. Several histologic entities were recorded: ependymomas - 12 cases, astrocytomas - 8 cases, hemangioblastomas - 3 cases, cavernomas - 6 cases, metastases - 2 cases, germ cell tumour - 1 case, malignant peripheral nerve sheath tumour - 1 case. Gross total excision was performed in 25 cases, with no mortality. In eight cases recurrences were recorded requiring the resumption of surgical treatment. In all cases physiotherapy-rehabilitation approach was used, and the outcome was correlated with pre-operatory motor deficits severity, 3 patients with thoracic high-grade astrocytoma underwent stereotactic spine radiosurgery (SSR) with Cyberknife abroad, stopping tumour growth one year after.&#x0D; Conclusions: Intramedullary spinal cord lesions (IMSCL) are rare conditions, and MRI development allows an early diagnosis of these tumours. To adequately counselled patients, with minor preoperative deficits, real expectations concerning the functional outcomes, in benign tumours, and even anatomical healing should be based still on refinements of radical surgical excision. Actual radiotherapy techniques should be used in aggressive tumours.

Mapping the functional anatomy and topography of the cardiac autonomic innervation for selective cardiac neuromodulation using MicroCT.

Background: Vagus nerve stimulation (VNS) has gained great importance as a promising therapy for a myriad of diseases. Of particular interest is the therapy of cardiovascular diseases, such as heart failure or atrial fibrillation using selective cardiac VNS. However, there is still a lack of organ-specific anatomical knowledge about the fascicular anatomy and topography of the cardiac branch (CB), which diminishes the therapeutic possibilities for selective cardiac neuromodulation. Here, we established a topographical and anatomical map of the superior cardiac VN in two animal species to dissect cervical and cardiac VN morphology. Methods: Autonomic nerves including superior CBs were harvested from domestic pigs and New Zeeland rabbits followed by imaging with microcomputed tomography (µCT) and 3D rendering. The data were analyzed in terms of relevant topographical and anatomical parameters. Results: Our data showed that cardiac vagal fascicles remained separated from other VN fascicles up to 22.19 mm (IQR 14.02–41.30 mm) in pigs and 7.68 mm (IQR 4.06–12.77 mm) in rabbits from the CB point and then started merging with other fascicles. Exchanges of nerve fascicles between sympathetic trunk (ST) and VN were observed in 3 out of 11 nerves, which might cause additional unwanted effects in unselective VNS. Our 3D rendered digital model of the cardiac fascicles was generated showing that CB first remained on the medial side where it branched off the VN, as also shown in the µCT data of 11 pig nerves, and then migrated towards the ventromedial site the further it was traced cranially. Conclusion: Our data provided an anatomical map of the cardiac vagal branches including cervical VN and ST for future approaches of selective cardiac neurostimulation, indicating the best position of selective cardiac VNS just above the CB point.

Social regulation of immediate early gene induction in gonadotropin releasing-hormone 1 neurons and singing behavior in canaries (Serinus canaria)

Social cues modulate the neuroendocrine control of reproduction. However, the neural systems involved in the integration of social cues are not well described. Gonadotropin-releasing hormone 1 (GnRH1) cells in the preoptic area (POA) are the final common node that links the brain with peripheral reproductive physiology. These experiments investigated whether induction of the immediate early gene, EGR1, in anatomically localized GnRH1 cell populations in Border canaries is regulated by the social environment. First, we characterized behavioral modifications in singing behavior and found males paired with a female for 2 weeks significantly reduced many aspects of singing behavior. However, paired males had a significantly higher percentage of GnRH1 cells co-labeled with EGR1. The second experiment manipulated the social environment by pairing males and females in mixed sex dyads, same sex dyads or housed birds in isolation. Only when birds are paired in mixed sex dyads was there a significantly greater percentage of GnRH1 cells expressing EGR1 cells. Increased GnRH1-EGR1 co-expression was localized to the rostral POA. These data reveal that discrete GnRH1 cells are involved in the neural integration of specific social cues and support the hypothesis that the POA exhibits functional topography related to courtship and sexual behaviors.

Ferdinando Rossi Lecture: the Cerebellar Cognitive Affective Syndrome-Implications and Future Directions.

The notion that the cerebellum is devoted exclusively to motor control has been replaced by a more sophisticated understanding of its role in neurological function, one that includes cognition and emotion. Early clinical reports, as well as physiological and behavioral studies in animal models, raised the possibility of a nonmotor role for the cerebellum. Anatomical studies demonstrate cerebellar connectivity with the distributed neural circuits linked with autonomic, sensorimotor, vestibular, associative and limbic/paralimbic brain areas. Identification of the cerebellar cognitive affective syndrome in adults and children underscored the clinical relevance of the role of the cerebellum in cognition and emotion. It opened new avenues of investigation into higher order deficits that accompany the ataxias and other cerebellar diseases, as well as the contribution of cerebellar dysfunction to neuropsychiatric and neurocognitive disorders. Brain imaging studies demonstrate the complexity of cerebellar functional topography, revealing a double representation of the sensorimotor cerebellum in the anterior lobe and lobule VIII and a triple cognitive representation in the cerebellar posterior lobe, as well as representation in the cerebellum of the intrinsic connectivity networks identified in the cerebral hemispheres. This paradigm shift in thinking about the cerebellum has been advanced by the theories of dysmetria of thought and the universal cerebellar transform, harmonizing the dual anatomic realities of homogeneously repeating cerebellar cortical microcircuitry set against the heterogeneous and topographically arranged cerebellar connections with extracerebellar structures. This new appreciation of the cerebellar incorporation into circuits that subserve cognition and emotion enables deeper understanding and improved care of our patients with cerebellar ataxias and novel cerebellar-based approaches to therapy in neuropsychiatry.

Sex differences in the functional topography of association networks in youth

Prior work has shown that there is substantial interindividual variation in the spatial distribution of functional networks across the cerebral cortex, or functional topography. However, it remains unknown whether there are sex differences in the topography of individualized networks in youth. Here, we leveraged an advanced machine learning method (sparsity-regularized non-negative matrix factorization) to define individualized functional networks in 693 youth (ages 8 to 23 y) who underwent functional MRI as part of the Philadelphia Neurodevelopmental Cohort. Multivariate pattern analysis using support vector machines classified participant sex based on functional topography with 82.9% accuracy (P < 0.0001). Brain regions most effective in classifying participant sex belonged to association networks, including the ventral attention, default mode, and frontoparietal networks. Mass univariate analyses using generalized additive models with penalized splines provided convergent results. Furthermore, transcriptomic data from the Allen Human Brain Atlas revealed that sex differences in multivariate patterns of functional topography were spatially correlated with the expression of genes on the X chromosome. These results highlight the role of sex as a biological variable in shaping functional topography.

Investigation of intermittent cutting mechanism of abrasive particles in ultrasonic-assisted external cylindrical honing

Ultrasonic-assisted honing, which is a finishing grinding method, has been considered effective for improving the cutting performance of abrasive particles. However, the effect mechanism of the ultrasonic vibration on the cutting process of abrasive particles has not yet been clarified, which hinders the application and development of this technology. In this study, new kinematics and cutting process models of a single abrasive particle in ultrasonic-assisted external cylindrical honing (UAECH) were established. The parameters and interruption conditions affecting the intermittent cutting process of the abrasive particle were clarified based on the coupling effect of ultrasonic vibration and rotation of workpiece. Finite element simulation analysis has revealed that the increases in ultrasonic frequency and amplitude can reduce the interruption threshold and cutting time proportion in the intermittent cutting process of abrasive particles mainly by increasing the relative velocity of abrasive particles. Furthermore, for the cutting depth and rotation speed, their influence on the intermittent cutting process is mainly based on the change of the deformation rate of workpiece material. Moreover, it was found that there was counteraction effect between the tangential forces on the symmetrical surfaces of the abrasive particle in UAECH, which can help reduce the tangential honing force and improve the honing performance. The experimental results demonstrated a significant improvement in the average tangential honing force in UAECH and novel dents surface topography, which can provide guidance for the application of ultrasonic vibration in the grinding field and development of forming processes for functional surface topography in honing.

Multimodal fusion analysis of functional, cerebrovascular and structural neuroimaging in healthy aging subjects.

Brain aging is a complex process that requires a multimodal approach. Neuroimaging can provide insights into brain morphology, functional organization, and vascular dynamics. However, most neuroimaging studies of aging have focused on each imaging modality separately, limiting the understanding of interrelations between processes identified by different modalities and their relevance to cognitive decline in aging. Here, we used a data-driven multimodal approach, linked independent component analysis (ICA), to jointly analyze magnetic resonance imaging (MRI) of grey matter volume, cerebrovascular, and functional network topographies in relation to measures of fluid intelligence. Neuroimaging and cognitive data from the Cambridge Centre for Ageing and Neuroscience study were used, with healthy participants aged 18-88 years (main dataset n=215 and secondary dataset n=433). Using linked ICA, functional network activities were characterized in independent components but not captured in the same component as structural and cerebrovascular patterns. Split-sample (n=108/107) and out-of-sample (n=433) validation analyses using linked ICA were also performed. Global grey matter volume with regional cerebrovascular changes and the right frontoparietal network activity were correlated with age-related and individual differences in fluid intelligence. This study presents the insights from linked ICA to bring together measurements from multiple imaging modalities, with independent and additive information. We propose that integrating multiple neuroimaging modalities allows better characterization of brain pattern variability and changes associated with healthy aging.

Topographical EEG Recordings of Visual Evoked Potentials in Mice using Multichannel Thin-film Electrodes.

Visual evoked potentials (VEP) allow the characterization of visual function in preclinical mouse models. Various methods exist to measure VEPs in mice, from non-invasive EEG, subcutaneous single-electrodes, and ECoG to fully invasive intracortical multichannel visual cortex recordings. It can be useful to acquire a global, topographical EEG-level characterization of visual responses previous to local intracortical microelectrode measurements in acute experimental settings. For example, one use case isto assess global cross-modal changes in VEP topography in deafness models before studying its effects on a local intracortical level. Multichannel epicranial EEG is a robust method to acquire such an overview measure of cortical visual activity.Multichannel epicranial EEG provides comparable results through a standardized, consistent approach to, for example, identify cross-modal, pathological, or age-related changes in cortical visual function. The current study presents a method to obtain the topographical distribution of flash-evoked VEPs with a 32-channel thin-film EEG electrode array in anesthetized mice. Combined with analysis in the time and frequency domain, this approach allows fast characterization and screening of the topography and basic visual properties of mouse cortical visual function, which can be combined with various acute experimental settings.

Self-adaptability and topological deformation of Ganlan architectural heritage: Conservation and regeneration of Lianghekou Tujia village in Western Hubei, China

The authenticity of architectural heritage is interpreted differently in diverse cultural traditions. Can this inspire the conservation and contemporary regeneration of architectural heritage to adapt to the changing needs of modern life and society, rather than static exhibits in museums? This research focuses on Ganlan (pile-built timber construction) architecture to demonstrate how adaptive conservation and regeneration can keep traditional construction systems living and sustainable. Ganlan, a vernacular architectural archetype in the humid subtropical regions of Asia, has the following common features: free plans with an assembling frame structure, open and interactive envelopes to cope with the hot and damp climate, and stilts to deal with the rugged terrain. This research employed a threefold method of field investigation, topological deformation, and experimental design in examining Lianghekou, a historic Tujia village in Western Hubei, China. The findings reveal that Tujia people build their stilt houses with adaptable features to meet the changing functional requirements and variable topographies. These traditions can be transmitted into the contemporary design, as our experimental design illustrates. The self-adaptability and topological deformation of Ganlan architectural heritage demonstrate a unique perspective of understanding authenticity, and contribute toward innovative application in the conservation and regeneration of vernacular architecture.

EndoFLIP Topography: Motor Patterns in an Obstructed Esophagus

EndoFLIP Topography: Motor Patterns in an Obstructed Esophagus

Linking Individual Differences in Personalized Functional Network Topography to Psychopathology in Youth

BackgroundThe spatial layout of large-scale functional brain networks differs between individuals and is particularly variable in the association cortex, implicated in a broad range of psychiatric disorders. However, it remains unknown whether this variation in functional topography is related to major dimensions of psychopathology in youth. MethodsThe authors studied 790 youths ages 8 to 23 years who had 27 minutes of high-quality functional magnetic resonance imaging data as part of the Philadelphia Neurodevelopmental Cohort. Four correlated dimensions were estimated using a confirmatory correlated traits factor analysis on 112 item-level clinical symptoms, and one overall psychopathology factor with 4 orthogonal dimensions were extracted using a confirmatory factor analysis. Spatially regularized nonnegative matrix factorization was used to identify 17 individual-specific functional networks for each participant. Partial least square regression with split-half cross-validation was conducted to evaluate to what extent the topography of personalized functional networks encodes major dimensions of psychopathology. ResultsPersonalized functional network topography significantly predicted unseen individuals’ major dimensions of psychopathology, including fear, psychosis, externalizing, and anxious-misery. Reduced representation of association networks was among the most important features for the prediction of all 4 dimensions. Further analysis revealed that personalized functional network topography predicted overall psychopathology (r = 0.16, permutation testing p < .001), which drove prediction of the 4 correlated dimensions. ConclusionsThese results suggest that individual differences in functional network topography in association networks is related to overall psychopathology in youth. Such results underscore the importance of considering functional neuroanatomy for personalized diagnostics and therapeutics in psychiatry.

Volumetric changes in specific neurofunctional subfields of the hippocampus in major depressive disorder.

There is evidence that hippocampal volume is abnormal in patients with major depressive disorder (MDD), but there have been no studies on volumetric changes in different subfields based on functional topography. This was investigated in the present study by comparing hippocampal neurofunctional subfield volumes between MDD patients and healthy control (HC) subjects. Patients with MDD (n = 44) and HCs (n = 27) recruited at Shanghai Traditional Chinese Medicine Integrated Hospital underwent a T1-weighted anatomical MRI scan in the sagittal orientation, and the data were used to calculate hippocampal subfield volumes. Logistic regression was used to evaluate the association between the volumes and risk of MDD. A nomogram for predicting MDD risk based on volume changes in different subfields was developed, and its predictive power was evaluated by calculating the concordance (C)-index. Compared with HCs, MDD patients showed reduced volume in hippocampal neurofunctional subfields, specifically in left (L)1, right (R)1, and R2 (related to emotion) and L2, L3, and R4 (related to cognition and perception). The logistic regression analysis revealed that the risk of MDD was 4.59-, 5.8-, 8.33-, and 6.92-fold higher with atrophies of L1, L2, L3, and R4, respectively. A nomogram for predicting MDD risk was developed based on age; sex; and hippocampal L1, L2, L3, and R4 subfield volumes and showed good accuracy, with a C-index of 0.784. Volumetric changes in the neurofunctional subfield of the hippocampus are potential imaging markers that can predict the occurrence of MDD.