Medial Area Research Articles

Decoding declarative memory process for predicting memory retrieval based on source localization.

Many studies have focused on understanding memory processes due to their importance in daily life. Differences in timing and power spectra of brain signals during encoding task have been linked to later remembered items and were recently used to predict memory retrieval performance. However, accuracies remain low when using non-invasive methods for acquiring brain signals, mainly due to the low spatial resolution. This study investigates the prediction of successful retrieval using estimated source activity corresponding either to cortical or subcortical structures through source localization. Electroencephalogram (EEG) signals were recorded while participants performed a declarative memory task. Frequency-time analysis was performed using signals from encoding and retrieval tasks to confirm the importance of neural oscillations and their relationship with later remembered and forgotten items. Significant differences in the power spectra between later remembered and forgotten items were found before and during the presentation of the stimulus in the encoding task. Source activity estimation revealed differences in the beta band power over the medial parietal and medial prefrontal areas prior to the presentation of the stimulus, and over the cuneus and lingual areas during the presentation of the stimulus. Additionally, there were significant differences during the stimuli presentation during the retrieval task. Prediction of later remembered items was performed using surface potentials and estimated source activity. The results showed that source localization increases classification performance compared to the one using surface potentials. These findings support the importance of incorporating spatial features of neural activity to improve the prediction of memory retrieval.

Associations between brain imaging and polygenic scores of mental health and educational attainment in children aged 9–11

Psychiatric disorders are highly heritable and polygenic, and many have their peak onset in late childhood and adolescence, a period of tremendous changes. Although the neurodevelopmental antecedents of mental illness are widely acknowledged, research in youth population cohorts is still scarce, preventing our progress towards the early characterization of these disorders. We included 7,124 children (9–11 years old) from the Adolescent Brain and Cognitive Development Study to map the associations of structural and diffusion brain imaging with common genetic variants and polygenic scores for psychiatric disorders and educational attainment. We used principal component analysis to derive imaging components, and calculated their heritability. We then assessed the relationship of imaging components with genetic and clinical psychiatric risk with univariate models and Canonical correlation analysis (CCA). Most imaging components had moderate heritability. Univariate models showed limited evidence and small associations of polygenic scores with brain structure at this age. CCA revealed two significant modes of covariation. The first mode linked higher polygenic scores for educational attainment with less externalizing problems and larger surface area. The second mode related higher polygenic scores for schizophrenia, bipolar disorder, and autism spectrum disorder to higher global cortical thickness, smaller white matter volumes of the fornix and cingulum, larger medial occipital surface area and smaller surface area of lateral and medial temporal regions. While cross-validation suggested limited generalizability, our results highlight the potential of multivariate models to better understand the transdiagnostic and distributed relationships between mental health and brain structure in late childhood.

Neural correlates of episodic memory in adults with Down syndrome and Alzheimer’s disease

BackgroundAdults with Down syndrome are at an ultra-high risk of developing early-onset Alzheimer’s disease. Episodic memory deficits are one of the earliest signs of the disease, but their association with regional brain atrophy in the population with Down syndrome has not been explored. We aimed to investigate the neuroanatomical correlates of episodic memory in adults with Down syndrome and symptomatic Alzheimer’s disease.MethodsSingle-center, cross-sectional study. A total of 139 adults with Down syndrome (85 asymptomatic and 54 with symptomatic Alzheimer’s disease) were included in the study (mean age 43.6 ± 10.9 years, 46% female). Episodic memory was assessed using the modified Cued Recall Test. Immediate (trial 1 free immediate recall, trial 3 free immediate recall, total free immediate recall score, and total immediate score) and delayed scores (free delayed recall score and total delayed score) were examined. Cortical thickness from magnetic resonance imaging was determined with surface-based morphometry using the FreeSurfer 6.0 software package. The clusters of reduced cortical thickness were compared between symptomatic and asymptomatic participants to create a cortical atrophy map. Then, the correlation between cortical thickness and the modified Cued Recall Test subscores were separately assessed in symptomatic and asymptomatic subjects, controlling for age, sex, and severity of intellectual disability.ResultsCompared with asymptomatic participants, those with symptomatic Alzheimer’s disease showed a pattern of cortical atrophy in posterior parieto-temporo-occipital cortices. In symptomatic subjects, trial 1 immediate free recall significantly correlated with cortical atrophy in lateral prefrontal regions. Trial 3 free immediate recall and total free immediate recall were associated with the most widespread cortical atrophy. Total immediate score was related to posterior cortical atrophy, including lateral parietal and temporal cortex, posterior cingulate cortex, precuneus, and medial temporal lobe areas. Delayed memory scores were associated with cortical atrophy in temporoparietal and medial temporal lobe regions. No significant relationships were observed between episodic memory measures and cortical atrophy in asymptomatic subjects.ConclusionsDifferent episodic memory measures were associated with cortical atrophy in specific brain regions in adults with Down syndrome and Alzheimer’s disease. These results overlap with those described in sporadic Alzheimer’s disease and further support the similarities between Down syndrome-associated Alzheimer’s disease and that in the general population.

The Dominance of Anticipatory Prefrontal Activity in Uncued Sensory-Motor Tasks.

Anticipatory event-related potentials (ERPs) precede upcoming events such as stimuli or actions. These ERPs are usually obtained in cued sensory–motor tasks employing a warning stimulus that precedes a probe stimulus as in the contingent negative variation (CNV) paradigms. The CNV wave has been widely studied, from clinical to brain–computer interface (BCI) applications, and has been shown to emerge in medial frontoparietal areas, localized in the cingulate and supplementary motor areas. Several dated studies also suggest the existence of a prefrontal CNV, although this component was not confirmed by later studies due to the contamination of ocular artifacts. Another lesser-known anticipatory ERP is the prefrontal negativity (pN) that precedes the uncued probe stimuli in discriminative response tasks and has been localized in the inferior frontal gyrus. This study aimed to characterize the pN by comparing it with the CNV in cued and uncued tasks and test if the pN could be associated with event preparation, temporal preparation, or both. To achieve these aims, high-density electroencephalographic recording and advanced ERP analysis controlling for ocular activity were obtained in 25 volunteers who performed 4 different visuomotor tasks. Our results showed that the pN amplitude was largest in the condition requiring both time and event preparation, medium in the condition requiring event preparation only, and smallest in the condition requiring temporal preparation only. We concluded that the prefrontal CNV could be associated with the pN, and this activity emerges in complex tasks requiring the anticipation of both the category and timing of the upcoming stimulus. The proposed method can be useful in BCI studies investigating the endogenous neural signatures triggered by different sensorimotor paradigms.

Comparison of the Effects of Isokinetic, Isometric, and Isotonic Exercises on Knee Osteoarthritis Using Ultrasound.

Introduction: This study aims to investigate the effects of different types of exercise on pain, functional capacity, muscle strength measured by an isokinetic dynamometer, and femoral cartilage (FC) thickness measured using ultrasound in patients with knee osteoarthritis (KOA).Methods: Sixty patients were randomized to isokinetic, isometric, and isotonic exercise groups, and exercise programs were completed five days a week over three weeks. The FC thickness for each knee was evaluated in medial, intercondylar, and lateral areas using ultrasound, and muscle strength was assessed by an isokinetic dynamometer. Activity levels were also measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). At three weeks from baseline, follow-up clinical measurements of knee muscle strength and FC thickness were performed.Results: A significant decrease was observed in all three groups in post-treatment visual analog scale (VAS) pain scores. In terms of evaluation of WOMAC scores, no significant difference was observed between the groups. In the isokinetic group, a significant increase was detected in extensor and flexor muscle strength measurements at the angular velocities of 60º/s and 180º/s. In the isotonic group, a statistically significant increase was detected in peak torque values of extensor and flexor muscles at 60º/s in the left knee only. Regarding FC thickness, a significant increase was found in the intercondylar area and the lateral condyle measurements of the left knee in the isokinetic group and the intercondylar area measurements of the right knee in the isometric group. In the isokinetic group, a statistically significant decrease was detected in the medial condyle of the right knee. It was observed that isokinetic exercise ended up with a significant increase in FC thickness in the intercondylar area and the lateral condyle of the left knee and a significant decrease in the medial condyle of the right knee.Conclusion: Isokinetic exercise is functionally superior to isometric and isotonic exercise, providing more significant improvements in muscle strength measurements and FC thickness. Further research is needed to determine the interactions among therapeutic exercises in patients with KOA that impact knee cartilage quantities.

Effects of treatment with a carbon monoxide donor and an activator of heme oxygenase 1 on the nociceptive, apoptotic and/or oxidative alterations induced by persistent inflammatory pain in the central nervous system of mice

The activation of heme oxygenase 1 (HO-1)/carbon monoxide (CO) inhibits chronic inflammatory pain, but its role in the central nervous system (CNS) is not entirely known. We evaluated whether the treatment with an HO-1 inducer, cobalt protoporphyrin IX (CoPP), or a CO-releasing molecule, tricarbonyldichlororuthenium(II)dimer (CORM-2), modulates the nociceptive, apoptotic and/or oxidative responses provoked by persistent inflammatory pain in the CNS. In C57BL/6 male mice with peripheral inflammation caused by complete Freund’s adjuvant (CFA), we assessed the effects of CORM-2 and CoPP on the expression of protein kinase B (Akt), the apoptotic protein BAX, and the antioxidant enzymes HO-1 and NADPH quinone oxidoreductase 1 (NQO1) in the periaqueductal gray matter (PAG), amygdala (AMG), ventral hippocampus (VHPC) and medial septal area (MSA). Our results showed that the increased expression of p-Akt caused by peripheral inflammation in the four analyzed brain areas was reversed by CORM-2 and CoPP therapies. Both treatments also normalized the upregulation of BAX induced by CFA on the VHPC and MSA. Oxidative stress, demonstrated with the decreased expression of HO-1 on the PAG and AMG, was normalized in CORM-2 and CoPP treated animals. CoPP also increased the expression of HO-1 on VHPC, and both treatments up-regulated the NQO1 levels on the PAG of CFA-injected animals. In conclusion, both CORM-2 and CoPP treatments inhibited the nociceptive and apoptotic responses generated by peripheral inflammation and/or potentiated the antioxidant responses in several brain areas revealing the new modulatory effects of these treatments in the CNS of animals with chronic inflammatory pain.

Abstract P2037: Activation Of A2A Adenosine Receptor Reduces Cardiac Dysfunction Resulting From Pulmonary Hypertension In Rats

Pulmonary hypertension (PH) is characterized by extensive pulmonary vascular remodeling, leading to right ventricle (RV) hypertrophy and dysfunction. This work evaluates the hypothesis that the activation of adenosine A2A receptor (AR-A2) by LASBio-1900 could interfere with the cardiac and vascular dysfunction on monocrotaline (MCT)-induced PH in rats. After 14 days of PH induction using a single injection of MCT (60 mg/kg i.p.), twelve male Wistar rats were randomly divided in groups and treated orally either with vehicle or LASSBio-1900 (180 μmol/kg/day). Hemodynamic parameters were obtained using the echocardiography and summarized in table 1. LASSBio-1900 reduced RV hypertrophy observed in PH because the Fulton index altered from 55.4 ± 2.3 to 35.3 ± 5.9% (p<0.05). HP increased RV systolic and diastolic pressure from 19.2 ± 2.0 and 4.7 ± 1.0 to 51.5 ± 5.2 and 11.9 ± 1.3 mmHg, respectively. Ventricular dysfunction was recovered with LASSBio-1900 treatment reducing pressures to 28.4 ± 4.0 and 6.5 ± 0.8 mmHg, indicating improvement of RV dysfunction. Pulmonary arteriole (PA) muscularization was evaluated by alpha- smooth muscle actin stained and vessel medial wall area was expressed as the percentage of the portion positively stained relative to total transversal area. The increase of the wall thickness of distal PA from 61.7 ± 1.1 to 83.24 ± 1.82 % was reduced by LASSBio-1900 (75.2 ± 3.4 %). Perivascular collagen in PA was evaluated through picrosirius red staining and interstitial fibrosis was measured by obtaining the total collagen area per arteriole area. PH increased the perivascular collagen deposition in 15.1 ± 1.3% however, treatment with LASSBio-1900 reduced to 8.7 ± 1.4% (p<0.05). Intense inflammation process on PH was confirmed with the increase of iNOS expression from 4.5 ± 0.3 (control) to 19.0 ± 0.9% (p<0.05) with reduction to 8.7 ± 1.4% when treated with LASSBio-1900. In conclusion, the agonist of AR-A2, named LASSBio-1900 improved RV function and pulmonary structural alteration in PH, indicating a new alternative for treatment of PH-induced RV dysfunction.

A novel endocast technique providing a 3D quantitative analysis of the gastrovascular system in Rhizostoma pulmo: An unexpected through-gut in cnidaria.

The investigation of jellyfish gastrovascular systems mainly focused on stain injections and dissections, negatively affected by thickness and opacity of the mesoglea. Therefore, descriptions are incomplete and data about tridimensional structures are scarce. In this work, morphological and functional anatomy of the gastrovascular system of Rhizostoma pulmo (Macri 1778) was investigated in detail with innovative techniques: resin endocasts and 3D X-ray computed microtomography. The gastrovascular system consists of a series of branching canals ending with numerous openings within the frilled margins of the oral arms. Canals presented a peculiar double hemi-canal structure with a medial adhesion area which separates centrifugal and centripetal flows. The inward flow involves only the "mouth" openings on the internal wing of the oral arm and relative hemi-canals, while the outward flow involves only the two outermost wings' hemi-canals and relative "anal" openings on the external oral arm. The openings differentiation recalls the functional characteristics of a through-gut apparatus. We cannot define the gastrovascular system in Rhizostoma pulmo as a traditional through-gut, rather an example of adaptive convergence, that partially invalidates the paradigm of a single oral opening with both the uptake and excrete function.

Technical details for inset of flaps in transfer of double-level gastroepiploic lymph node flaps for lower extremity lymphedema

In this study, the method that can be followed to ensure rapid and uncomplicated recovery of lymph node flap (LNF) applied in the medial of the ankle for lymphedema treatment was investigated. Thirty-seven patients with class II of lower limb lymphedema underwent transfer of gastroepiploic LNF to the medial ankle and popliteal fossa areas. At the popliteal fossa region, the wound could always be closed primarily by the advancement of neighboring skin. The wound closure could be classified into three types at the medial ankle area (A) The partially exposed LNF was covered with a split-thickness skin graft (STSG) (n=9). (B) A larger local flap was elevated, and the donor site of the local flap was covered with STSG (n=18). (C) The skin flap's donor site was treated with pre-tie sutures (n=10). In the popliteal region, there was no complication of wound healing. In the ankle region, the wound was coated by a thin layer of hematoma over the exposed LNF in 5 patients of group A. It healed secondarily except for one patient who needed a secondary skin graft. The healing was perfect in group B. In group C the healing was good, but there was a hypertrophic scar in 7 patients and required steroid injection later. To avoid complications of the gastroepiploic LNF at the medial ankle, it should be entirely covered by an anteriorly-based local flap, and the donor site defect of the local flap can be treated with either pre-tie sutures or a skin graft.

Visual timing-tuned responses in human association cortices and response dynamics in early visual cortex

Quantifying the timing (duration and frequency) of brief visual events is vital to human perception, multisensory integration and action planning. Tuned neural responses to visual event timing have been found in association cortices, in areas implicated in these processes. Here we ask how these timing-tuned responses are related to the responses of early visual cortex, which monotonically increase with event duration and frequency. Using 7-Tesla functional magnetic resonance imaging and neural model-based analyses, we find a gradual transition from monotonically increasing to timing-tuned neural responses beginning in the medial temporal area (MT/V5). Therefore, across successive stages of visual processing, timing-tuned response components gradually become dominant over inherent sensory response modulation by event timing. This additional timing-tuned response component is independent of retinotopic location. We propose that this hierarchical emergence of timing-tuned responses from sensory processing areas quantifies sensory event timing while abstracting temporal representations from spatial properties of their inputs.

Refined Concept of Motor Supply to the Medial Periorbital Area Relevant to Periorbital Surgery.

Mimetic muscles in the medial periorbital area have been thought to be innervated solely by the angular nerve. Recently, however, the upper medial palpebral branch and lower palpebral branch were reported as additional motor suppliers in this area. This study aimed to define all the motor nerve systems passing through the medial canthal area. Motor nerve branches that passed through the medial canthal region were identified and traced thoroughly from the parotid gland to their destinations under a surgical microscopic field in 74 hemifaces. The courses, anatomical positions of, and anatomical relationships between the angular nerve and the upper medial palpebral branch were observed. The upper medial palpebral branch and the angular nerve were found in all samples within a 3-mm to 6-mm area lateral to the intersecting point of the medial orbital rim and medial canthal ligament. The upper medial palpebral branch supplied the upper eyelid, whereas the angular nerve supplied the extraorbicularis muscles in the medial periorbital area. The medial pretarsal area of the upper eyelid was supplied solely by the pretarsal branches of the upper medial palpebral branch, which was formed by uniting three or four minor branches that traveled throughout the anterior cheek. Two separate motor nerve systems, the upper medial palpebral branch and the angular nerve, exist in the medial canthal area. The upper medial palpebral branch course along the medial orbital rim is considered as a facial nerve danger zone.

Impact of natural conditions and anthropogenic activities on groundwater quality in Puntang volcanic area, West Java, Indonesia.

The Puntang area in the southern mountains of West Java has potential water resources that are used to fulfill the community's raw water. The rapid development of the region and tourism will affect the quality of groundwater. This research was conducted on the slopes of Mount Puntang with the aim of analyzing natural and anthropogenic conditions on groundwater quality. Measurements and groundwater samples are taken from 5 springs, 10 dug wells and 8 drilling wells. The research method begins with a literature study followed by data collection in the field and laboratory analysis. Data analysis used statistical analysis and hydrogeochemical spatial analysis. Hydrogeochemical analysis using Piper diagrams. Based on the analysis results, it is known that the groundwater facies are CaCl, CaMgCl CaHCO3, and NaHCO3. The CaCl facies, enrichment of Cl- is caused by contamination of volcanic domain. The CaMgCl facies has enrichment of Mg2+ cations in the process of groundwater and rock water interactions. The high Cl- value in the proximal area is influenced by volcanic domain, while the Cl- value in the medial and distal areas may be influenced by anthropogenic. The CaHCO3 facies is influenced by local meteoric water, with a high structural control that shows water flowing through the fracture. The NaHCO3 facies is a wellbore in the intermediate groundwater flow and anthropogenic influences have occurred. The hydrochemical evolution that occurs is that Ca2+ becomes Mg2+ and then turns into Na+. The CaMgHCO3 facies dominates the proximal to distal area. The presence of HCO3 - indicates that groundwater mixing has occurred and is influenced by the decomposition of organic matter. Indications of groundwater mixing can be seen in groundwater with NaKHCO3 facies in the distal area. The medial and distal areas are densely populated areas which also affect groundwater. Geological and environmental conditions around the water resources are one of the supporting data to determine polluting sources.

Bypass Surgery for Moyamoya Disease, Part 1: Special Considerations and Techniques

In this review article, the author describes the eligible patients, concept, surgical technique, and long-term outcome of the superficial temporal artery to middle cerebral artery(STA-MCA)anastomosis and the ultimate indirect bypass, called encephalo-duro-myo-arterio-pericranial synangiosis(EDMAPS)for adult moyamoya disease, in addition to the novel diagnostic criteria. The procedure dramatically improves or normalizes the cerebral blood flow immediately after surgery and thus contributes to preventing ischemic complications during and after surgery. However, the arterial wall of these patients is extremely thin and fragile; therefore, the surgeons should be trained extensively and have absolute confidence in their ability to perform this procedure. The surgeons should be aware that STA-MCA anastomosis frequently induces the hyper-perfusion phenomenon in adult patients with moyamoya due to prolonged cerebral ischemia. The extent of craniotomy determines the amount of surgical collaterals after indirect surgery; thus, a wide craniotomy including most of the frontal area, especially the medial frontal area, is critical to improve the postoperative prognosis. This procedure can markedly diminish the dangerous periventricular collateral channels and provides excellent long-term outcomes for up to 20 years after surgery. Long-term follow-ups longer than 20 years are important to monitor the patients with this unique and peculiar disease.

A Computer-Assisted Approach Regarding the Optimization of the Geometrical Planning of Medial Opening Wedge High Tibial Osteotomy

Opening wedge high tibial osteotomy (OWHTO) is a surgical procedure often used to eliminate the effects of knee osteoarthritis, a disease that is becoming more widespread worldwide. Optimizing the geometric planning of this operation is a very important preparatory step for the success of the intervention and rapid postoperative recovery. This optimization is performed in two main directions. The first direction evaluates the intraoperative behavior of the tibia during the osteotomy by optimizing four geometric parameters that characterize geometric planning. The second direction aims at a postoperative evaluation of the flat tibia-osteosynthesis assembly taking into account the optimal position on the medial–lateral articular line through which the corrected mechanical axis of the tongue passes and implicitly offloads the transfer from the medial area to the side of the knee. The research methods used are exclusively computer-assisted such as: computer-aided design (hereinafter CAD) for geometric modeling of the tibia taking into account the real bone structure, the finite element method (hereinafter FEM) for performing numerical analyses and design of the experiment (hereinafter DOE) for the design of the research. The results obtained are eloquent and clearly presented and can be important elements for orthopedic doctors at the geometric planning stage of the OWHTO.

Features of ball impact in straight, curve and knuckle kicks in soccer

The quantitative relationship between kicking motion and ball behaviour can be easily explained by detecting the impact point and foot posture. In previous studies, the impact point of a kicking foot was difficult to capture using visual tracking. Thus, a virtual surface modelling technique was applied in this study to clarify the differences in the three-dimensional foot speed, impact point and foot posture between straight, curve, and knuckle kicks in soccer, as well as the relationship between the kick motion and ball rotation. An optical three-dimensional motion capture system (VICON) was used to record the kicking motion. The impact points of the straight, curve, and knuckle kicks were found to be centrally located in the instep area, at a lower (more downwards) inside area, and at the medial area between the instep and inside areas of the kicking foot, respectively. Moreover, an impact with a greater ‘swing vector deviation angle (relative to the direction from the impact point to the centre of gravity of the ball)’ is necessary for ball rotation. The impact point detection method employed in this study can be applied to other ball impact estimations beyond soccer kicks.

Effect of zoledronic acid with or without methylprednisolone on 3D bone area and bone shape in patients with symptomatic knee osteoarthritis: A post-hoc analysis of the ZAP2 trial

ObjectiveTo evaluate the effect of annual infusions of zoledronic acid (ZA) with or without a single injection of methylprednisolone, compared to placebo, on quantitative magnetic resonance imaging 3-D bone area and bone shape in participants with symptomatic knee osteoarthritis (OA). MethodsThis was a post-hoc analysis of the ZAP2 trial. Active appearance modelling was used to assess bone area (mm2) and femur bone shape (B-score) in 262 participants (mean 61.8 ± 8.0 years, 51% female) at baseline, 6, and 24 months. Radiographic joint space narrowing (JSN) was measured at baseline. An ‘OA shape’ was defined as a B-score of >1.96. ResultsAt baseline 65% of participants demonstrated an OA shape. Treatment with ZA plus methylprednisolone but not ZA alone, compared to placebo, was associated with significantly slower expansion in bone area at the medial femoral (-33.9 mm2, 95% confidence interval [CI] -61.8 to -6.0) and lateral femoral (-22.0 mm2, 95%CI -40.7 to -3.4) compartments over 24 months. B-score increased in all groups, with no significant between-group differences. There were significant interactions of JSN (grade 0 vs grade 1–2) and B-score (≤1.96 vs >1.96) with treatment effect on bone area (p < 0.05), such that ZA plus methylprednisolone slowed the expansion of medial and lateral femoral bone area over 24 months in participants with JSN grade 1–2 or a B-score of >1.96. ConclusionsZA plus methylprednisolone may retard expansion of bone area over 24 months, but ZA alone may not. Neither ZA with or without methylprednisolone slowed progression of bone shape over 6 or 24 months.

Cortical Motion Perception Emerges from Dimensionality Reduction with Evolved Spike-Timing-Dependent Plasticity Rules.

The nervous system is under tight energy constraints and must represent information efficiently. This is particularly relevant in the dorsal part of the medial superior temporal area (MSTd) in primates where neurons encode complex motion patterns to support a variety of behaviors. A sparse decomposition model based on a dimensionality reduction principle known as non-negative matrix factorization (NMF) was previously shown to account for a wide range of monkey MSTd visual response properties. This model resulted in sparse, parts-based representations that could be regarded as basis flow fields, a linear superposition of which accurately reconstructed the input stimuli. This model provided evidence that the seemingly complex response properties of MSTd may be a by-product of MSTd neurons performing dimensionality reduction on their input. However, an open question is how a neural circuit could carry out this function. In the current study, we propose a spiking neural network (SNN) model of MSTd based on evolved spike-timing-dependent plasticity and homeostatic synaptic scaling (STDP-H) learning rules. We demonstrate that the SNN model learns compressed and efficient representations of the input patterns similar to the patterns that emerge from NMF, resulting in MSTd-like receptive fields observed in monkeys. This SNN model suggests that STDP-H observed in the nervous system may be performing a similar function as NMF with sparsity constraints, which provides a test bed for mechanistic theories of how MSTd may efficiently encode complex patterns of visual motion to support robust self-motion perception.SIGNIFICANCE STATEMENT The brain may use dimensionality reduction and sparse coding to efficiently represent stimuli under metabolic constraints. Neurons in monkey area MSTd respond to complex optic flow patterns resulting from self-motion. We developed a spiking neural network model that showed MSTd-like response properties can emerge from evolving spike-timing-dependent plasticity with STDP-H parameters of the connections between then middle temporal area and MSTd. Simulated MSTd neurons formed a sparse, reduced population code capable of encoding perceptual variables important for self-motion perception. This model demonstrates that complex neuronal responses observed in MSTd may emerge from efficient coding and suggests that neurobiological plasticity, like STDP-H, may contribute to reducing the dimensions of input stimuli and allowing spiking neurons to learn sparse representations.

Morphometric characteristics and histotopography of the left atrium walls

Background. Knowledge of the anatomical features of the left atrium walls will minimize complications during the Cox-Maze surgery.&#x0D; Aim. To clarify common features and local anatomical specificities of the anterosuperior, lateral and inferior walls of the left atrial body of the heart of an adult.&#x0D; Material and methods. From 60 preparations of the hearts of men and women aged 3589 years who died from non-cardiac causes, 61 histotopograms and 180 anatomical sections of the left atrium walls were made. A stereoscopic microscope (4.715 magnification), a histological microscope (40 magnification), and an image recognition program were used. Nonparametric dispersion, correlation, one-way regression analysis were applied. The significance of differences was assessed by the MannWhitney U-test. The results were presented as medians.&#x0D; Results. Anatomical markers of the anterosuperior wall were a compact group of transverse myocardial fibers (anterior interatrial Bachmann bundle) and a thinned section of the lower third of the medial half of the wall. A feature of the lateral wall was a group of oblique myocardial fibers (left lateral ridge). The inferior wall was characterized by well-developed subepicardial tissue. Anteroposterior wall in the medial area (5130 m) and lateral wall (5243 m) were thin. The epicardium with subepicardial tissue in the medial part of the inferior wall was thicker (4750 m) than in the lateral (2651 m) and anterosuperior (2535 m) walls. The myocardium of the anteroposterior wall (2714 m) was thicker than the myocardium of both the lateral (2213 m) and inferior wall in its central (1947 m) and lateral (1913 m) sections. The median thickness of the endocardium of different walls varied from 335 to 426 m. The wall thickness in the upper third mostly depended primarily on the myocardium thickness, and in the inferior third on the epicardium and subepicardial tissue thickness.&#x0D; Conclusion. For the walls of the left atrium, their thickening towards the coronary sulcus was common due to the subepicardial adipose tissue. The peculiarities were the differences of the left atrium walls in thickness and their unique pattern of myocardial anatomy.

Semaglutide treatment attenuates vessel remodelling in ApoE−/− mice following vascular injury and blood flow perturbation

Background and aimsRandomized clinical studies have shown a reduction in cardiovascular outcomes with glucagon-like peptide 1 receptor agonist (GLP-1RA) treatment with the hypothesized mechanisms being an underlying effect on atherosclerosis. Here, we aimed to assess the pharmacological effects of semaglutide in an atheroprone murine model that recapitulates central mechanisms related to vascular smooth muscle cell (VSMC) phenotypic switching and endothelial dysfunction known to operate within the atherosclerotic plaque. MethodsIn study A, we employed an electrical current to the carotid artery in ApoE−/− mice to induce severe VSMC injury and death, after which the arteries were allowed to heal for 4 weeks. In study B, a constrictive cuff was added for 6 h at the site of the healed segment to induce a disturbance in blood flow. ResultsCompared to vehicle, semaglutide treatment reduced the intimal and medial area by ∼66% (p = 0.007) and ∼11% (p = 0.0002), respectively. Following cuff placement, expression of the pro-inflammatory marker osteopontin and macrophage marker Mac-2 was reduced (p < 0.05) in the semaglutide-treated group compared to vehicle. GLP-1R were not expressed in murine carotid artery and human coronary vessels with and without atherosclerotic plaques, and semaglutide treatment did not affect proliferation of cultured primary human VSMCs. ConclusionsSemaglutide treatment reduced vessel remodelling following electrical injury and blood flow perturbation in an atheroprone mouse model. This effect appears to be driven by anti-inflammatory and -proliferative mechanisms independent of GLP-1 receptor-mediated signalling in the resident vascular cells. This mechanism of action may be important for cardiovascular protection.

Personal socio-cultural preferences modulate neural correlates of decisions to socialize with powerful persons.

Social power differences fundamentally shape the behavioral interaction dynamics of groups and societies. While it has long been recognized that individual socio‐cultural preferences mitigate social interactions involving persons of power, there is limited empirical data on the underlying neural correlates. To bridge this gap, we asked university student participants to decide whether they were willing to engage in social activities involving their teachers (higher power status), classmates (equal power status), or themselves (control) while functional brain images were acquired. Questionnaires assessed participants' preferences for power distance, uncertainty avoidance, and cultural intelligence. As expected, participants generally accepted more social interactions with classmates than teachers. Also, left inferior frontal activity was higher when accepting than when rejecting social interactions with teachers. Critically, power distance preferences further modulated right lateral frontoparietal activity contrasting approach relative to avoidance decisions towards teachers. In addition, uncertainty avoidance modulated activity in medial frontal, precuneus, and left supramarginal areas distinguishing approach decisions towards teachers relative to classmates. Cultural intelligence modulated neural responses to classmate approach/avoidance decisions in anterior cingulate and left parietal areas. Overall, functional activities in distinct brain networks reflected different personal socio‐cultural preferences despite observed social decisions to interact with others of differential power status. Such findings highlight that social approach or avoidance behaviors towards powerful persons involves differential subjective neural processes possibly involved in computing implicit social utility.