Gray Regions Research Articles

Gray System-Based Identification and Pre-Culling of Outliers Applied to Magnetic Sensor in Aeromagnetic Compensation

In aeromagnetic surveys, poor aircraft heading and weather may frequently cause a classical optically-pumped sensor to enter into or close to its dead zone, which results in unavoidable outliers that seriously reduce aeromagnetic compensation. To address these problems, a method to identify rapidly and pre-cull magnetic outliers based on the gray system theory is proposed to reduce their negative influence during the estimation of coefficients and target detection robustness. By constructing a gray region of aeromagnetic data and then checking whether the data at the end points of the region are normal, aeromagnetic outliers can be culled. The simulation results show that even if the outlier rate is increased to 20%, the average of the correct culling rate of the proposed method can still reach 99.67%, at which the culling effect is highly robust. We constructed an experimental survey platform and conducted a flight test. The results show that the improvement ratio of the proposed method can reach 4.36, which is 10.38 times higher than the conventional method.

Performance Optimization of Original Aluminum Ash Coating

Aluminum ash is a kind of industrial solid waste. Original aluminum ash (OAA) can be prepared into original aluminum ash spray powder (OAASP) through hydrolysis treatment, and the original aluminum ash coating (OAAC) can be prepared on the surface of the substrate by plasma spraying. In order to optimize the performance of the OAAC, the OAASP was screened to select the appropriate particle size to improve the flowability of the powder. Then, the influence of the alumina content on coating performance was studied through comparative experiments. The micro morphology of the coating was analyzed, and the performance parameters of the coating were tested. The results show that the spray powder with a particle size of 120–150 mesh accounts for the largest proportion of OAASP, and its flowability is better than that of unsieved OAASP, which is suitable for coating preparation. The performance of the coating can be improved by adding high-purity alumina. When the Al2O3 addition is 50%, the porosity of the coating is 0.131%, the adhesive strength is 17.12 MPa, the microhardness is 713.36 HV, and the abrasion rate 10.31 mg/min. Compared with the coating without Al2O3, the porosity is decreased by 19.63%, the adhesive strength is increased by 5.35%, the microhardness is increased by 17.61%, and the abrasion rate is decreased by 19.83%. There are regions with different brightness on the surface of the coating with Al2O3. After semiquantitative analysis, the main phase in the bright region is Al2O3, and the main phases in the dark and gray regions are Al2O3, SiO2, and Fe3O4. The performance of the OAAC can be optimized by improving the flowability of the sprayed powder and increasing the alumina content.

Left Ear Hearing Predicts Functional Activity in the Brains of Patients with Alzheimer's Disease Dementia.

To determine whether central speech processing ability, as measured by hearing in noise, differs between right and left ears in adults with Alzheimer's disease related dementia (AD) as well as whether differences in central speech processing ability correlate with an fMRI-based measurement of global functional brain connectivity. This prospective study was carried out at a tertiary referral center. Patients with an AD diagnosis and pure tone averages 40 dB HL or better were included. They were examined using resting-state fMRI and underwent central audiometric testing using the Dichotic Sentence Identification Test (DSI), the Dichotic Digits Test (DD), and the Synthetic Sentence Identification Test (SS), which test hearing in noise. DSI scores were correlated with resting-state fMRI connectivity between 361 distinct gray matter brain regions of interest (ROIs). Average global connectivity was calculated as mean functional connectivity between an ROI and the other 360 regions, a quantitative marker representing overall functional connectivity in the brain. Sixteen subjects had adequate fMRI and hearing data. The average age was 71.5 years old (±6.0). The average DSI score for the left ear was 40% (±34%) compared to 90% (±10%) in the right ear (P < .001). No difference between ears was noted on the DD. SS does not differentiate between ears, but worsening scores were noted with increasing background noise. Of the fMRI ROIs, 269 of the 361 had multiple comparison corrected significant correlations between global connectivity and DSI of the left ear (P = .004, r = .673), and all 269 showed higher functional connectivity for individuals with higher left DSI score. No correlations between DSI of the right ear and functional connectivity were found. Correlation was noted between left sided DSI and functional connectivity in patients with AD. Auditory input from the left ear was more susceptible to impairment, suggesting that side-specific auditory input may influence central auditory processing.

Surface Defects Detection of Stamping and Grinding Flat Parts Based on Machine Vision.

Currently, surface defect detection of stamping grinding flat parts is mainly undertaken through observation by the naked eye. In order to improve the automatic degree of surface defects detection in stamping grinding flat parts, a real-time detection system based on machine vision is designed. Under plane illumination mode, the whole region of the parts is clear and the outline is obvious, but the tiny defects are difficult to find; Under multi-angle illumination mode, the tiny defects of the parts can be highlighted. In view of the above situation, a lighting method combining plane illumination mode with multi-angle illumination mode is designed, and five kinds of defects are automatically detected by different detection methods. Firstly, the parts are located and segmented according to the plane light source image, and the defects are detected according to the gray anomaly. Secondly, according to the surface of the parts reflective characteristics, the influence of the reflection on the image is minimized by adjusting the exposure time of the camera, and the position and direction of the edge line of the gray anomaly region of the multi-angle light source image are used to determine whether the anomaly region is a defect. The experimental results demonstrate that the system has a high detection success rate, which can meet the real-time detection rEquation uirements of a factory.

P‐182: A Numerical Analysis of Current Efficiency Hump at Low Grey in the OLED Devices

The hump behavior of current efficiency in OLEDs(Organic Light Emitting Diodes) were often observed at the low voltage under certain charge balance condition. The color non‐linearity with image sticking in the low voltage level was found to be well correlated with the existence of hump phenomena. In this paper, we explained the mechanism of hump is trade‐off between Langevin recombination and SRH(Schokley‐Reed‐Hall) recombination, and found out SRH recombination could be mainly controlled by EML(Emitting Layer)/ETL(Electron Transport Layer) interface barrier using OLED device simulation. Additionally we could suggest the conditions that reduce the hump at the low grey region to improve the performance of OLED device. Finally the color non‐linearity of OLED device was improved by elimination of hump behavior.

The blockade of D1/D2-like dopamine receptors in the lateral periaqueductal gray region affects morphine self-administration with and without exercise in rats

Introduction: The periaqueductal gray (PAG) region plays an essential role in the modulation of nociception. Also, lateral PAG (lPAG) is involved in reward circuitry by the dopaminergic system in addiction. The present study investigated the blockade of D1/D2-like dopamine receptors in the lateral PAG region affects morphine self-administration with and without exercise. Methods: Rats were divided into six groups. The rats were initially trained to receive small pellets of food by pressing an active lever in the self administration apparatus. Exercise groups were run on a treadmill at 20m/min, 5 days/week, for 4 weeks before the surgery. Then rats were bilaterally implanted with cannulae in lPAG. The SCH23390 and sulpiride were microinjected into the lPAG, 5min before receiving morphine. Afterward, the animals were allowed to self administer morphine in 2h sessions over 11 consecutive days. At last, the numbers of lever pressing, infusion times and withdrawal symptoms were measured. Results: The results showed the number of active lever pressing was significantly increased in the morphine group compared to other groups in self-infusion during 11 days. Exercise significantly reversed the detrimental effects of morphine self-administration after five days. However, the synergistic effect of injected sulpiride into the lPAG region with exercise training was more pronounced on the amelioration of morphine than on the combinatory effect of SCH23390 with exercise. Conclusion: The findings suggested that the D2 dopamine receptor in the lPAG region was involved in the morphine addiction via the dopaminergic system and exercise training in combination with antagonists could reduce the rewarding properties of morphine.

The effect of periaqueductal gray's metabotropic glutamate receptor subtype 8 activation on locomotor function following spinal cord injury.

Background and aims The pathophysiology of spinal cord injury is very complex. One of the debilitating aspects of spinal cord injury in addition to pain is a defect in motor function below the lesion surface. In this study, we tried to assess the modulatory effect of (S)-3,4-Dicarboxyphenylglycine (DCPG), a metabotropic glutamate receptor subtype 8 (mGluR8) agonist, on animal's locomotor functions in a model of compression spinal cord injury. Methods We used a contusion method (T6-T8) for induction of spinal cord injury. Male Wistar rats were randomly assigned to five equal groups (n = 10 per group). Clips compression injury model was used to induce spinal cord injury. Three weeks post injury DCPG, siRNA (small interfering Ribonucleic Acid) and normal saline (vehicle) were administered intra-ventrolaterally to the periaqueductal gray (PAG) region. Motor function, were assessed through BBB (Basso, Beattie, and Bresnahan Locomotor Rating Scale) and ladder walking test. In addition, the effects of DCPG on axonal regeneration in corticospinal tract were evaluated. Results We found that DCPG could improve motor function and axonal regeneration in corticospinal tract when compared to siRNA group. Conclusions The results revealed that activation of mGluR8 in PAG is capable to improve motor function and of axonal regeneration due to the inhibitory effect on glutamate transmission on the spinal cord surface and also the elimination of the deleterious effect of glutamate on the regeneration of the injured area as an excitatory neurotransmitter. Implications Our findings in this study showed that, more attention should be paid to glutamate and its receptors in spinal cord injury studies, whether at the spinal or cerebral level, especially in the field of motor function after spinal cord injury.

Pathways of extra- and intercellular diffusion of colored substances in the blackened xylem of Diospyros kaki

Some species of Diospyros form the black wood that is known as ebony. Infrequently, D. kaki forms wood with black patterning that is called “kurogaki” in Japan and is highly valued. To understand the mechanism of formation of the blackened xylem, we attempted to clarify the pathways of diffusion of colored substances from the site of their biosynthesis to their deposition in secondary xylem. We observed colored substances in pits and intercellular spaces and we recorded the deposition of colored substances in the cell walls of wood fibers. In gray and black regions, we found colored substances in the pits between xylem cells, in blind pits and in intercellular spaces. At the boundary between whitish and black regions, areas of coloration in the cell walls of wood fibers gradually increased in size from the whitish to the black regions. Heavy deposition of colored substances was observed in the inner region of the secondary walls of wood fibers. Furthermore, coloration of the outer region of the secondary walls and compound middle lamella (CML) of wood fibers gradually became stronger toward the black regions. Our observations suggest that pit-pairs and intercellular spaces might provide the pathways for inter- and extracellular diffusion of colored substances, respectively. In addition, colored substances might penetrate the cell walls of wood fibers, moving from the lumen into the cell wall.

Reduced Thalamus Volume and Enhanced Thalamus and Fronto-Parietal Network Integration in the Chess Experts.

The ability of chess experts depends to a large extent on spatial visual processing, attention, and working memory, all of which are thought to be mediated by the thalamus. This study explored whether continued practice and rehearsal over a long period of time results in structural changes in the thalamic region. We found smaller gray matter volume regions in the thalami of expert Chinese chess players in comparison with novice players. We then used these regions as seeds for resting-state functional connectivity analysis and observed significantly strengthened integration between the thalamus and fronto-parietal network in expert Chinese chess players. This strengthened integration that includes a group of brain regions showing an increase in activation to external stimulation, particularly during tasks relying on working memory and attention. Our findings demonstrate structural changes in the thalamus caused by a wide range of engagement in chess problem solving, and that this strengthened functional integration with widely distributed circuitry better supports high-level cognitive control of behavior.

743Combining deep learning method with optical coherence tomography for ablation lesion assessment

Abstract Background The immediate effect of radiofrequency catheter ablation (RFA) on the tissue is not directly visualized. Optical coherence tomography (OCT) is an imaging technique that uses light to capture histology-like images with a penetration depth of 1-3 mm in the cardiac tissue. There are two specific features of ablation lesions in the OCT images: the disappearance of birefringence artifacts in the lateral and sudden decrease of signal at the bottom (Figure panel A and D). These features can not only be used to recognize the ablation lesions from the OCT images by eye, but also be used to train a machine learning model for automatic lesion segmentation. In recent years, deep learning methods, e.g. convolutional neural networks, have been used in medical image analysis and greatly increased the accuracy of image segmentation. We hypothesize that using a convolutional neural network, e.g. U-Net, can locate and segment the ablation lesions in the OCT images. Purpose To investigate whether a deep learning method such as a convolutional neural network optimized for biomedical image processing, could be used to segment ablation lesions in OCT images automatically. Method 8 OCT datasets with ablation lesions were used for training the convolutional neural network (U-Net model). After training, the model was validated by two new OCT datasets. Dice coefficients were calculated to evaluate spatial overlap between the predictions and the ground truth segmentations, which were manually segmented by the researchers (its value ranges from 0 to 1, and "1" means perfect segmentation). Results The U-Net model could predict the central parts of lesions automatically and accurately (Dice coefficients are 0.933 and 0.934), compared with the ground truth segmentations (Figure panel B and E). These predictions could reveal the depths and diameters of the ablation lesions correctly (Figure panel C and F). Conclusions Our results showed that deep learning could facilitate ablation lesion identification and segmentation in OCT images. Deep learning methods, integrated in an OCT system, might enable automatic and precise ablation lesion visualization, which may help to assess ablation lesions during radiofrequency ablation procedures with great precision. Figure legend Panel A and D: the central OCT images of the ablation lesions. The blue arrows indicate the lesion bottom, where the image intensity suddenly decreases. The white arrows indicate the birefringence artifacts (the black bands in the grey regions). Panel B and E: the ground true segmentations of lesions in panel A and D. Panel C and F: the predictions by U-Net model of the lesions in panel A and D. A scale bar representing 500 μm is shown in each panel. Abstract Figure

Tau pathology and relative cerebral blood flow are independently associated with cognition in Alzheimer\u2019s disease

PurposeWe aimed to investigate associations between tau pathology and relative cerebral blood flow (rCBF), and their relationship with cognition in Alzheimer’s disease (AD), by using a single dynamic [18F]flortaucipir positron emission tomography (PET) scan.MethodsSeventy-one subjects with AD (66 ± 8 years, mini-mental state examination (MMSE) 23 ± 4) underwent a dynamic 130-min [18F]flortaucipir PET scan. Cognitive assessment consisted of composite scores of four cognitive domains. For tau pathology and rCBF, receptor parametric mapping (cerebellar gray matter reference region) was used to create uncorrected and partial volume-corrected parametric images of non-displaceable binding potential (BPND) and R1, respectively. (Voxel-wise) linear regressions were used to investigate associations between BPND and/or R1 and cognition.ResultsHigher [18F]flortaucipir BPND was associated with lower R1 in the lateral temporal, parietal and occipital regions. Higher medial temporal BPND was associated with worse memory, and higher lateral temporal BPND with worse executive functioning and language. Higher parietal BPND was associated with worse executive functioning, language and attention, and higher occipital BPND with lower cognitive scores across all domains. Higher frontal BPND was associated with worse executive function and attention. For [18F]flortaucipir R1, lower values in the lateral temporal and parietal ROIs were associated with worse executive functioning, language and attention, and lower occipital R1 with lower language and attention scores. When [18F]flortaucipir BPND and R1 were modelled simultaneously, associations between lower R1 in the lateral temporal ROI and worse attention remained, as well as for lower parietal R1 and worse executive functioning and attention.ConclusionTau pathology was associated with locally reduced rCBF. Tau pathology and low rCBF were both independently associated with worse cognitive performance. For tau pathology, these associations spanned widespread neocortex, while for rCBF, independent associations were restricted to lateral temporal and parietal regions and the executive functioning and attention domains. These findings indicate that each biomarker may independently contribute to cognitive impairment in AD.

CARMA—Cellular Automata with Refined Mesh Adaptation—The Easy Way of Generation of Structural Topologies

This paper is focused on the development of a Cellular Automata algorithm with the refined mesh adaptation technique and the implementation of this algorithm in topology optimization problems. Traditionally, a Cellular Automaton is created based on regular discretization of the design domain into a lattice of cells, the states of which are updated by applying simple local rules. It is expected that during the topology optimization process the local rules responsible for the evaluation of cell states can drive the solution to solid/void resulting structures. In the proposed approach, the finite elements are equivalent to cells of an automaton and the states of cells are represented by design variables. While optimizing engineering structural elements, the important issue is to obtain well-defined solutions: in particular, topologies with smooth boundaries. The quality of the structural topology boundaries depends on the resolution level of mesh discretization: the greater the number of elements in the mesh, the better the representation of the optimized structure. However, the use of fine meshes implies a high computational cost. We propose, therefore, an adaptive way to refine the mesh. This allowed us to reduce the number of design variables without losing the accuracy of results and without an excessive increase in the number of elements caused by use of a fine mesh for a whole structure. In particular, it is not necessary to cover void regions with a very fine mesh. The implementation of a fine grid is expected mainly in the so-called grey regions where it has to be decided whether a cell becomes solid or void. The benefit of the proposed approach, besides the possibility of obtaining high-resolution, sharply resolved fine optimal topologies with a relatively low computational cost, is also that the checkerboard effect, mesh dependency, and the so-called grey areas can be eliminated without using any additional filtering. Moreover, the algorithm presented is versatile, which allows its easy combination with any structural analysis solver built on the finite element method.

Prophylactic treatment of ischemic stroke with Coffea arabica in rats: A preliminary study

Introduction: Ischemic stroke is the third leading cause of death worldwide. The purpose of the current study was to assess the preliminary effects of Coffea arabica (CA) in experimentally-induced stroke in an animal model in the context of neuroprotection. The study was also designed to document the prophylactic use of CA in patients experiencing stroke symptoms.&#x0D; Methods: A total of 25 male albino rats, 12 months of age, were purchased from the local market. They were acclimatized for seven days and divided into 5 groups. Each group consists of 5 subjects. Each subject was trained on a specific test for behavioral assessment. Behavioral modulation of each rat was performed using four tests, namely cylinder test, staircase test, forelimb flexion test, and pasta test. All the tests were performed as per standard criteria at the 4th, 8th, 12th, and 14th day of drug administration. The subjects were administered with caffeine (2.4 mg/kg) and CA (100 mg/kg and 200 mg/kg extract) doses for 14 days to assess the prophylactic use of CA. After 14 days of treatment, rats were subject to ischemic stroke induction using the middle cerebral artery ligation method. All four tests used for behavior modulation were applied at 24, 48, and 72 hours intervals of postsurgery. The subjects were further sacrificed for histopathological investigations. Statistical analysis was performed with SPSS (V. 22) software using one-way ANOVA.&#x0D; Results: Our findings suggest that treatment with CA, 100 mg/kg and 200 mg/kg orally, decreases the infarct volume. However, there are not many considerable differences that were found in both doses. Histopathological investigations revealed characteristic structural changes occurring in both gray and white brain regions, depending on the severity, location, and duration of the ischemic stroke.&#x0D; Conclusion: CA is a harmless and active mediator in the dissolution of blood clots and the recovery of stroke in rats. It is an agent that has been found to be efficient for brain activity with few side effects and behavioral modifications.

An Intuitionistic Fuzzy Set Approach for Multi-attribute Information Classification and Decision-Making

This article introduced a new multi-attribute information classification method by employing intuitionistic fuzzy set (IFS) approach. The proposed method was referred as four-way intuitionistic decision space (4WIDS). In the 4WIDS, IFS theory was used to model the inherent uncertainty of multi-attribute information. For generating more precise level of decision-rules, granular computing (GrC) approach was employed. The proposed 4WIDS method was appropriate for the classification of the multi-attribute information into four different regions as positive IFS, negative IFS, uncertain IFS and gray IFS regions. Detail methodology of the 4WIDS was explained by presenting its representation in a precise way. This study also presented various definitions, properties and theorems in the support of the 4WIDS method. The 4WIDS was applied in benchmark datasets that included Pima Indians diabetes, Thyroid disease, Fisher’s Iris and Spambase datasets. Experimental results including statistical analysis indicated that the proposed 4WIDS outperformed existing classification methods, such as Naive Bayes, Decision tree, PART, J48, logistic model trees (LMT), rough set (RS), gray multi-granulation rough set (GMGRS) and multi-granulation fuzzy rough set (MGFRS).

Borsa İstanbul Teknoloji Endeksi (XUTEK) Şirketlerinin Altman Z-Skor Analizi İle Değerlendirilmesi

Altman Z-Skor ile finansal başarısızlık ve iflas riskini analiz etmektir. Teknoloji firmaları başlangıç ​​yatırımları ve AR-GE süreçleri arasında yoğun risk taşımaktadır. Teknoloji firmalarının bulunduğu bölgelerde sektör, çok hızlı dönüşümlerin meydana geldiği ve hızlı aksiyonlar bulunmaktadır. 16 teknoloji şirketi üzerinde gerçekleştirilmiştir. Altman Z-Skor ile ilgili finansal başarısızlık ve iflas riskini ölçümleme yapabilmek 16 teknoloji içindir ait 2019 bilanço grafikleri arasından elde edilen sonuçlar değerlendirilmiştir. Altman Z-Skoru modeli kullanılır, BİST 2019 hisse değer değişmektedir.

Vision loss, gaze palsy, and nystagmus in a patient with leukemia

A 22-year old male with a history of B-cell acute lymphoblastic leukemia with recent bone marrow transplantation and on immunosuppressive therapy presented with painless, subacute vision loss of two weeks duration. He exhibited a horizontal gaze palsy, nystagmus, and mildly swollen and hyperemic optic discs with peripapillary flame hemorrhage on retinal exam. He had bilateral cecocentral scotomas on visual field exam, and MRI of his brain/orbits demonstrated hyperintensities in the hypothalamus, periaqueductal gray, and dorsal rostral medullary regions. After continued progression of symptoms despite discontinuation of the patient’s tacrolimus, an empiric trial of IV thiamine treatment was started before the patient’s lab vitamin levels were available, given strong clinical suspicion for a nutritional etiology. The patient’s clinical presentation improved dramatically, and he achieved a final visual acuity of 20/20, full visual fields bilaterally, and resolution of nystagmus. A final diagnosis of Wernicke’s encephalopathy was supported by his clinical course, imaging findings, and further confirmation with blood thiamine levels. This case presents unique ocular manifestations of Wernicke’s encephalopathy and highlights the importance of early diagnosis in this potentially reversible condition.

Enforcing a Force–Displacement Curve of a Nonlinear Structure Using Topology Optimization with Slope Constraints

The objective of this study is to develop an optimization methodology to find a layout that traces a prescribed force–displacement curve through a topology optimization approach. To this end, we propose an objective function to minimize the difference between a prescribed force–displacement curve and the curve calculated at each iteration of the optimization process. Slope constraints are introduced to solve issues encountered when using a small number of target points. In addition, a projection filter is employed to suppress the gray region observed between the solid and void regions, which generally occurs when using a density-based filter. A recently proposed energy interpolation scheme is implemented to stabilize the instability in the nonlinear analysis, which generally results from excessive distortion in the void region when the structure is modeled on a fixed mesh in the topology optimization process. To validate the outlined methodology, several case studies with different types of nonlinearity and structural features of the obtained layouts are investigated.

Pearl millet protein bar: nutritional, organoleptic, textural characterization, and in-vitro protein and starch digestibility.

Pearl millet, a nutritionally remarkable cereal with a sustainable yield in the grey regions of India, is not consumed much. Consumption of Nutrition bars has gained momentum in recent years and considering this, in the present study pearl millet-based protein bars are formulated to increase its consumption rate and establish it as a reliable source of protein and other nutrients. The proximate and mineral composition of the three variants of pearl millet incorporated (25, 27.5, 30%) protein bars were analyzed using standard protocols. The acceptability of the bars was assessed using the 9-point hedonic scale among twenty panelists. The textural parameters were measured by Perten TVT 6700 Texture Analyzer. The in-vitro digestibility of protein (IVPD) and starch (IVSD) of the best variant was also estimated. The bars provide 15.74-18.32g of protein, 332-379kcal energy, 74.53-83.87mg calcium, and 555.93-603.80mg phosphorous per 100g. The results showed that the organoleptic parameters of the bars were not affected by the proportion of ingredients. Whereas the increase in pearl millet incorporation marginally increased textural properties such as hardness, cohesiveness, and chewiness. The IVPD of the selected variant is 75.65 ± 0.02% and IVSD revealed 252.00 ± 10.00mg of maltose is released per 100g of the sample. The protein bars are nutritionally beneficial and appealing. This study gives scope for the production of pearl millet-based convenience foods that will raise the consumption pattern of pearl millet at the household level.

Neural mechanisms underlying concurrent listening of simultaneous speech

Can we identify what two people are saying at the same time? Although it is difficult to perfectly repeat two or more simultaneous messages, listeners can report information from both speakers. In a concurrent/divided listening task, enhanced attention and segregation of speech can be required rather than selection and suppression. However, the neural mechanisms of concurrent listening to multi-speaker concurrent speech has yet to be clarified. The present study utilized functional magnetic resonance imaging to examine the neural responses of healthy young adults listening to concurrent male and female speakers in an attempt to reveal the mechanism of concurrent listening. After practice and multiple trials testing concurrent listening, 31 participants achieved performance comparable with that of selective listening. Furthermore, compared to selective listening, concurrent listening induced greater activation in the anterior cingulate cortex, bilateral anterior insula, frontoparietal regions, and the periaqueductal gray region. In addition to the salience network for multi-speaker listening, attentional modulation and enhanced segregation of these signals could be used to achieve successful concurrent listening. These results indicate the presence of a potential mechanism by which one can listen to two voices with enhanced attention to saliency signals.

The inhibiting role of periaqueductal gray metabotropic glutamate receptor subtype 8 in a rat model of central neuropathic pain

ABSTRACTThe pathophysiology of neuropathic pain is very complex. It involves several environmental and central mechanisms. In this study, we tried to assess the modulatory effect of (S)-3,4-Dicarboxyphenylglycine (DCPG), a metabotropic glutamate receptor subtype 8 (mGluR8) agonist, in a model of chronic central neuropathic pain in male rats. We used a spinal cord contusion method (T6-T8) for the induction of chronic central neuropathic pain.Male Wistar rats were randomly assigned to 5 equal groups (n = 10 per group). Clips compression injury model was used to induce chronic central neuropathic pain. Three weeks after spinal cord injury DCPG, siRNA and normal saline were administered intra-ventrolaterally to the periaqueductal gray (PAG) region. Paw withdrawal response to acetone (cold allodynia) was assessed through acetone test. In addition, the effects of DCPG on rostral ventromedial medulla (RVM) off-cells activity were evaluated with immunohistochemistry. mGluR8 expressions were also measured.We found that treatment with DCPG increased pain threshold in acetone test. In addition, immunohistochemical evaluation of RVM off-cells showed that DCPG increased the suppressive function of these cells.The results revealed that activation of mGluR8 in PAG is capable to improve pain threshold via modulation of RVM off-cells activity.Abbreviations SCI: spinal cord injury; DCPG: (S)-3,4-dicarboxyphenylglycine; PAG: periaqueductal gray; siRNA: small interfering ribonucleic acid; RVM: rostral ventromedial medulla; mGluR: metabotropic glutamate receptor