Application of proton magnetic resonance spectroscopy in metabolic alterations of prefrontal white and gray matter in depression adolescents

BACKGROUND Cases of depression among adolescents are gradually increasing.The study of the physiological basis of cognitive function from a biochemical perspective has therefore been garnering increasing attention.Depression has been hypothesized to be associated with the brain biochemical metabolism of the anterior cingulate gyrus,frontal lobe white matter,and the thalamus.AIM To explore the application of proton magnetic resonance spectroscopy(1H-MRS)in the metabolic alterations in the prefrontal white matter(PWM)and gray matter(GM)in adolescents with depression.METHODS 1H-MRS was performed for semi-quantitative analysis of the biochemical metabolites N-acetylaspartate(NAA),choline(Cho)complexes,creatine(Cr),and myoinositol(mI)in bilateral PWM,anterior cingulate GM,and thalami of 31 adolescent patients with depression(research group)and 35 healthy adolescents(control group),and the NAA/Cr,Cho/Cr,and mI/Cr ratios were calculated.Meanwhile,Hamilton Depression Scale(HAMD)and Wechsler Memory Scale were used to assess the degree of depression and memory function in all adolescents.The correlation of brain metabolite levels with scale scores was also analyzed.RESULTS The research group had markedly higher HAMD-24 scores and lower memory quotient(MQ)compared with the control group(P<0.05).Adolescents with depression were found to have lower bilateral PWM NAA/Cr and Cho/Cr ratios compared with healthy adolescents(P<0.05).The mI/Cr ratios were found to be similar in both groups(P>0.05).The bilateral anterior cingulate GM NAA/Cr,Cho/Cr,and mI/Cr also did not demonstrate marked differences(P>0.05).No statistical inter-group difference was determined in NAA/Cr of the bilateral thalami(P>0.05),while bilateral thalamic Cho/Cr and mI/Cr were reduced in teenagers with depression compared with healthy adolescents(P<0.05).A significant negative correlation was observed between the HAMD-24 scores in adolescents with depression with bilateral PWM NAA/Cr and Cho/Cr and were inversely linked to bilateral thalamic Cho/Cr and mI/Cr(P<0.05).In adolescents with depressions,MQ positively correlated with right PWH NAA/Cr,left PWH Cho/Cr,and bilateral thalamic Cho/Cr and mI/Cr.CONCLUSION PWM and thalamic metabolic abnormalities might influence teen depression,and the reduction in bilateral PWM NAA/Cr and Cho/Cr could be related to the neuropathology of adolescents with depression suffering from memory impairment.There exists a possibility of dysfunction of nerve cell membrane phospholipids in the thalami of adolescent patients with depression.

Persistent alterations in gray matter in COVID-19 patients experiencing sleep disturbances:a 3-month longitudinal study

Sleep disturbances are among the most prevalent neuropsychiatric symptoms in individuals who have recovered from severe acute respiratory syndrome coronavirus 2 infections.Previous studies have demonstrated abnormal brain structures in patients with sleep disturbances who have recovered from coronavirus disease 2019(COVID-19).However,neuroimaging studies on sleep disturbances caused by COVID-19 are scarce,and existing studies have primarily focused on the long-term effects of the virus,with minimal acute phase data.As a result,little is known about the pathophysiology of sleep disturbances in the acute phase of COVID-19.To address this issue,we designed a longitudinal study to investigate whether alterations in brain structure occur during the acute phase of infection,and verified the results using 3-month follow-up data.A total of 26 COVID-19 patients with sleep disturbances(aged 51.5±13.57 years,8 women and 18 men),27 COVID-19 patients without sleep disturbances(aged 47.33±15.98 years,9 women and 18 men),and 31 age-and gender-matched healthy controls(aged 49.19±17.51 years,9 women and 22 men)were included in this study.Eleven COVID-19 patients with sleep disturbances were included in a longitudinal analysis.We found that COVID-19 patients with sleep disturbances exhibited brain structural changes in almost all brain lobes.The cortical thicknesses of the left pars opercularis and left precuneus were significantly negatively correlated with Pittsburgh Sleep Quality Index scores.Additionally,we observed changes in the volume of the hippocampus and its subfield regions in COVID-19 patients compared with the healthy controls.The 3-month follow-up data revealed indices of altered cerebral structure(cortical thickness,cortical grey matter volume,and cortical surface area)in the frontal-parietal cortex compared with the baseline in COVID-19 patients with sleep disturbances.Our findings indicate that the sleep disturbances patients had altered morphology in the cortical and hippocampal structures during the acute phase of infection and persistent changes in cortical regions at 3 months post-infection.These data improve our understanding of the pathophysiology of sleep disturbances caused by COVID-19.

Gray Matter Volume Changes over the Whole Brain in the Bulbar-and Spinal-onset Amyotrophic Lateral Sclerosis: a Voxel-based Morphometry Study

Objective To investigate cerebral structural signatures of the bulbar-and spinal-onset amyotrophic lateral sclerosis(ALS) using voxel-based morphometry on magnetic resonance imaging.Methods The MR structural images of the brain were obtained from 65 ALS patients(15 bulbar-onset, 50 spinalonset) and 65 normal controls(NC) on a 3.0 T MRI system. Gray matter(GM) volume changes were investigated by voxel-based morphometry, and the distribution of the brain regions with volume changes was compared between ALS and normal controls, as well as between bulbar-onset and spinal-onset ALS based on Neuromorphometrics atlas.Results On voxel-level the decreased volume of brain regions in ALS patients was located in the right precentral gyrus(r Prc Gy) and right middle frontal gyrus compared with that in NC. The bulbar-onset ALS presented extramotor cortex atrophy(fronto-temporal pattern), including left medial orbital gyrus, left inferior temporal gyrus and right middle temporal gyrus; the spinal-onset ALS suffered from motor cortex atrophy(r Prc Gy dominance) and extra-motor cortex atrophy(fronto-temporal and extra-fronto-temporal pattern) compared with NC. The spinal-onset ALS featured by GM volume loss of left postcentral gyrus and bulbar-onset ALS featured by GM volume loss of left middle temporal gyrus compared with each other. Conclusions The asymmetric GM atrophy of the motor cortex and extra-motor cortex represents the common MRI structural signatures of spinal-onset ALS, and sole extra-motor cortex atrophy represents the structural signatures of bulbar-onset ALS. The present study also demonstrated that the pattern of GM damage is likely to distribute wider in spinal-onset ALS than in bulbar-onset ALS.

Regional gray matter abnormality in hepatic myelopathy patients after transjugular intrahepatic portosystemic shunt: a voxel-based morphometry study

Hepatic myelopathy is a complication seen in patients with chronic liver failure with physiologic or iatrogenic portosystemic shunting. The main symptom is progressive lower limb dyskinesia. The role of the brain motor control center in hepatic myelopathy is unknown. This study aimed to investigate the gray matter changes in patients with hepatic myelopathy secondary to transjugular intrahepatic portosystemic shunt and to examine their clinical relevance. This was a cross-sectional study. Twenty-three liver failure patients with hepatic myelopathy(hepatic myelopathy group), 23 liver failure patients without hepatic myelopathy(non-hepatic myelopathy group) after transjugular intrahepatic portosystemic shunt, and 23 demographically matched healthy volunteers were enrolled from March 2014 to November 2016 at Xijing Hospital, Air Force Military Medical University(Fourth Military Medical University), China. High-resolution magnetization-prepared rapid gradient-echo brain imaging was acquired. Group differences in regional gray matter were assessed using voxel-based morphometry analysis. The relationship between aberrant gray matter and motor characteristics was investigated. Results demonstrated that compared with the non-hepatic myelopathy group, gray matter volume abnormalities were asymmetric, with decreased volume in the left insula(P = 0.003), left thalamus(P = 0.029), left superior frontal gyrus(P = 0.006), and right middle cingulate cortex(P = 0.021), and increased volume in the right caudate nucleus(P = 0.017), corrected with open-source software. The volume of the right caudate nucleus in the hepatic myelopathy group negatively correlated with the lower limb clinical rating of the Fugl-Meyer Assessment(r = –0.53, P = 0.01). Compared with healthy controls, patients with and without hepatic myelopathy exhibited overall increased gray matter volume in both thalami, and decreased gray matter volume in both putamen, as well as in the globus pallidus, cerebellum, and vermis. The gray matter abnormalities we found predominantly involved motor-related regions, and may be associated with motor dysfunction. An enlarged right caudate nucleus might help to predict weak lower limb motor performance in patients with preclinical hepatic myelopathy after transjugular intrahepatic portosystemic shunt. This study was approved by the Ethics Committee of Xijing Hospital, Air Force Military Medical University(Fourth Military Medical University), China(approval No. 20140227-6) on February 27, 2014.

Changes of brain gray matter structure in Parkinson's disease patients with dementia

Voxel-based morphometry is gaining considerable interest for studies examining Parkinson＇s disease dementia patients. In this study, 12 patients with clinically defined Parkinson＇s disease and dementia and 12 non-demented patients with Parkinson＇s disease were examined using a T1WI three-dimensional fast spoiled gradient echo sequence. Gray matter data were analyzed using a voxel-based morphometry method and independent sample t-test based on Statistical Parametric Mapping 5 software. Differences in gray matter volume were represented with statistical parametric mapping. Compared with Parkinson＇s disease patients without dementia, decreased gray matter volume in Parkinson＇s disease dementia patients was observed in the bilateral superior temporal gyrus, bilateral posterior cingulate and left cingulate gyrus, right parahippocampal gyrus and hippocampus, right precuneus and right cuneus, left inferior frontal gyrus and left insular lobe. No increased gray matter volume was apparent. These data indicate that gray matter atrophy in the limbic system and cerebral neocortex is related to the presence of dementia.

Assessment of gray matter heterotopia by magnetic resonance imaging

AIM:To evaluate magnetic resonance imaging(MRI) features of different types of gray matter heterotopia.METHODS:Between June 2005 and December 2009,the medical records and MRI studies of patients with gray matter heterotopia were reviewed.The MRI morphologic findings of heterotopia were recorded along with the presence and type of associated cranial malformations.Available clinical and electrophysiological data were also recorded.RESULTS:20 patients were included in the study.Their ages ranged from 9 mo to 39 years with a mean age of 15 years.All patients suffered from epileptic seizures.According to the location of heterotopia,patients were classified into three groups:subependymal(12),subcortical(5) and band(3) heterotopia.CONCLUSION:MRI was useful in diagnosing and differentiating between various types of gray matter heterotopia.The severity of clinical manifestations of heterotopia was related to the location and pattern of heterotopia.Determination of heterotopia type and its extent is useful for management planning and predicting prognosis.

Correlation between white matter damage and gray matter lesions in multiple sclerosis patients

We observed the characteristics of white matter fibers and gray matter in multiple sclerosis patients, to identify changes in diffusion tensor imaging fractional anisotropy values following white matter fiber injury. We analyzed the correlation between fractional anisotropy values and changes in whole-brain gray matter volume. The participants included 20 patients with relapsing-remitting multiple sclerosis and 20 healthy volunteers as controls. All subjects underwent head magnetic resonance imaging and diffusion tensor imaging. Our results revealed that fractional anisotropy values decreased and gray matter volumes were reduced in the genu and splenium of corpus callosum, left anterior thalamic radiation, hippocampus, uncinate fasciculus, right corticospinal tract, bilateral cingulate gyri, and inferior longitudinal fasciculus in multiple sclerosis patients. Gray matter volumes were significantly different between the two groups in the right frontal lobe（superior frontal, middle frontal, precentral, and orbital gyri）, right parietal lobe（postcentral and inferior parietal gyri）, right temporal lobe（caudate nucleus）, right occipital lobe（middle occipital gyrus）, right insula, right parahippocampal gyrus, and left cingulate gyrus. The voxel sizes of atrophic gray matter positively correlated with fractional anisotropy values in white matter association fibers in the patient group. These findings suggest that white matter fiber bundles are extensively injured in multiple sclerosis patients. The main areas of gray matter atrophy in multiple sclerosis are the frontal lobe, parietal lobe, caudate nucleus, parahippocampal gyrus, and cingulate gyrus. Gray matter atrophy is strongly associated with white matter injury in multiple sclerosis patients, particularly with injury to association fibers.

Assessing gray matter volume in patients with idiopathic rapid eye movement sleep behavior disorder

Idiopathic rapid eye movement sleep behavior disorder(iRBD) is often a precursor to neurodegenerative disease. However, voxel-based morphological studies evaluating structural abnormalities in the brains of iRBD patients are relatively rare. This study aimed to explore cerebral structural alterations using magnetic resonance imaging and to determine their association with clinical parameters in iRBD patients. Brain structural T1-weighted MRI scans were acquired from 19 polysomnogram-confirmed iRBD patients(male:female 16:3; mean age 66.6 ± 7.0 years) and 20 age-matched healthy controls(male:female 5:15; mean age 63.7 ± 5.9 years). Gray matter volume(GMV) data were analyzed based on Statistical Parametric Mapping 8, using a voxel-based morphometry method and two-sample t-test and multiple regression analysis. Compared with controls, iRBD patients had increased GMV in the middle temporal gyrus and cerebellar posterior lobe, but decreased GMV in the Rolandic operculum, postcentral gyrus, insular lobe, cingulate gyrus, precuneus, rectus gyrus, and superior frontal gyrus. iRBD duration was positively correlated with GMV in the precuneus, cuneus, superior parietal gyrus, postcentral gyrus, posterior cingulate gyrus, hippocampus, lingual gyrus, middle occipital gyrus, middle temporal gyrus, and cerebellum posterior lobe. Furthermore, phasic chin electromyographic activity was positively correlated with GMV in the hippocampus, precuneus, fusiform gyrus, precentral gyrus, superior frontal gyrus, cuneus, inferior parietal lobule, angular gyrus, superior parietal gyrus, paracentral lobule, and cerebellar posterior lobe. There were no significant negative correlations of brain GMV with disease duration or electromyographic activity in iRBD patients. These findings expand the spectrum of known gray matter modifications in iRBD patients and provide evidence of a correlation between brain dysfunction and clinical manifestations in such patients. The protocol was approved by the Ethics Committee of Huashan Hospital(approval No. KY2013-336) on January 6, 2014. This trial was registered in the ISRCTN registry(ISRCTN18238599).

Compression analysis of the gray and white matter of the spinal cord

The spinal cord is composed of gray matter and white matter.It is well known that the properties of these two tissues differ considerably.Spinal diseases often present with symptoms that are caused by spinal cord compression.Understanding the mechanical properties of gray and white matter would allow us to gain a deep understanding of the injuries caused to the spinal cord and provide information on the pathological changes to these distinct tissues in several disorders.Previous studies have reported on the physical properties of gray and white matter,however,these were focused on longitudinal tension tests.Little is known about the differences between gray and white matter in terms of their response to compression.We therefore performed mechanical compression test of the gray and white matter of spinal cords harvested from cows and analyzed the differences between them in response to compression.We conducted compression testing of gray matter and white matter to detect possible differences in the collapse rate.We found that increased compression(especially more than 50%compression)resulted in more severe injuries to both the gray and white matter.The present results on the mechanical differences between gray and white matter in response to compression will be useful when interpreting findings from medical imaging in patients with spinal conditions.

Application of Renewal Gray GM (1,1) Model to Prediction of Landslide Deformation

The gray renewal GM (1,1) landslide prediction model was established by improving the gray model. Based on the established model, the author has made prediction of landslide deformation to the Xiangjiapo landslide and the Lianziya dangerous rock body. The results show that the gray renewal GM (1,1) model can supplement the new information in time and remove the old information which reduces the meaning of the information because of time lapse. Therefore, the model is closer to reality.

Magnetic resonance morphometry of the loss of gray matter volume in Parkinson's disease patients

Voxel-based morphometry can be used to quantitatively compare structural differences and func-tional changes of gray matter in subjects. In the present study, we compared gray matter images of 32 patients with Parkinson’s disease and 25 healthy controls using voxel-based morphometry based on 3.0 T high-field magnetic resonance T1-weighted imaging and clinical neurological scale scores. Results showed that the scores in Mini-Mental State Examination and Montreal Cognitive Assessment were lower in patients compared with controls. In particular, the scores of visuospatial/executive function items in Montreal Cognitive Assessment were significantly reduced, but mean scores of non-motor symptoms significantly increased, in patients with Parkinson’s dis-ease. In addition, gray matter volume was significantly diminished in Parkinson’s disease patients compared with normal controls, including bilateral temporal lobe, bilateral occipital lobe, bilateral parietal lobe, bilateral frontal lobe, bilateral insular lobe, bilateral parahippocampal gyrus, bilateral amygdale, right uncus, and right posterior lobe of the cerebel um. These findings indicate that voxel-based morphometry can accurately and quantitatively assess the loss of gray matter volume in patients with Parkinson＇s disease, and provide essential neuroimaging evidence for multisystem pathological mechanisms involved in Parkinson’s disease.

Regional gray matter atrophy and neuropsychologcal problems in relapsing-remitting multiple sclerosis

In multiple sclerosis, gray matter atrophy is extensive, and cognitive deficits and mood disorders are frequently encountered. It has been conjectured that focal atrophy is associated with emotional decline. However, conventional MRI has revealed that the pathological characteristics cannot fully account for the mood disorders. Moreover, there is no correlation between cognitive disorders and MRI results in clinically isolated syndromes or in cases of definite multiple sclerosis. In this casecontrol study, voxel-based morphometric analysis was performed on 11 subjects with relapsing-remitting multiple sclerosis, and the results show that these patients exhibit gray matter atrophy. Moreover, the gray matter atrophy in the superior and middle gyri of the right frontal lobe in patients with multiple sclerosis was correlated with scores from the Hamilton Anxiety Rating Scale. The scores obtained with the Repeatable Battery for the Assessment of Neuropsychological Status were associated with gray matter atrophy in the middle gyrus of the left frontal lobe, the superior and middle gyrus of the right frontal lobe, the middle gyrus of the left cingulate, the superior and middle gyri of the left frontal lobe, and the triangular area of the left frontal lobe. However, there was no statistical significance. These findings suggest that the cingulate and frontal cortices of the dominant hemisphere are the most severely atrophic regions of the brain, and this atrophy is correlated with cognitive decline and emotional abnormalities.

Application of Gray Metabolic GM (1,1) Model in Prediction of Annual Total Yields of Chinese Aquatic Products

To predict the annual total yields of Chinese aquatic products in future five years ( 2011-2015) ,based on the theory and method of gray system,this paper firstly establishes a conventional GM ( 1,1) model and a gray metabolic GM ( 1,1) model respectively to predict the annual total yields of Chinese aquatic products in 2006-2009 and compare the prediction accuracy between these two models. Then,it selects the model with higher accuracy to predict the annual total yields of Chinese aquatic products in future five years. The comparison indicates that gray metabolic GM ( 1,1) model has higher prediction accuracy and smaller error,thus it is more suitable for prediction of annual total yields of aquatic products. Therefore,it adopts the gray metabolic GM ( 1,1) model to predict annual total yields of Chinese aquatic products in 2011-2015. The prediction results of annual total yields are 55. 32,57. 46,59. 72,62. 02 and 64. 43 million tons respectively in future five years with annual average increase rate of about 3. 7% ,much higher than the objective of 2. 2% specified in the Twelfth Five-Year Plan of the National Fishery Development ( 2011 to 2015) . The results of this research show that the gray metabolic GM ( 1,1) model is suitable for prediction of yields of aquatic products and the total yields of Chinese aquatic products in 2011-2015 will totally be able to realize the objective of the Twelfth Five-Year Plan.

Healthy individuals vs patients with bipolar or unipolar depression in gray matter volume

BACKGROUND Previous studies using voxel-based morphometry(VBM)revealed changes in gray matter volume(GMV)of patients with depression,but the differences between patients with bipolar disorder(BD)and unipolar depression(UD)are less known.AIM To analyze the whole-brain GMV data of patients with untreated UD and BD compared with healthy controls.METHODS Fourteen patients with BD and 20 with UD were recruited from the Mental Health Center of Shantou University between August 2014 and July 2015,and 20 nondepressive controls were recruited.After routine three-plane positioning,axial T2WI scanning was performed.The connecting line between the anterior and posterior commissures was used as the scanning baseline.The scanning range extended from the cranial apex to the foramen magnum.Categorical data are presented as frequencies and were analyzed using the Fisher exact test.RESULTS There were no significant intergroup differences in gender,age,or years of education.Disease course,age at the first episode,and Hamilton depression rating scale scores were similar between patients with UD and those with BD.Compared with the non-depressive controls,patients with BD showed smaller GMVs in the right inferior temporal gyrus,left middle temporal gyrus,right middle occipital gyrus,and right superior parietal gyrus and larger GMVs in the midbrain,left superior frontal gyrus,and right cerebellum.In contrast,UD patients showed smaller GMVs than the controls in the right fusiform gyrus,left inferior occipital gyrus,left paracentral lobule,right superior and inferior temporal gyri,and the right posterior lobe of the cerebellum,and larger GMVs than the controls in the left posterior central gyrus and left middle frontal gyrus.There was no difference in GMV between patients with BD and UD.CONCLUSION Using VBM,the present study revealed that patients with UD and BD have different patterns of changes in GMV when compared with healthy controls.

Computerized White Matter and Gray Matter Extraction from MRI of Brain Image

Automated segmentation of white matter (WM) and gray matter (GM) is a very important task for detecting multiple diseases. The paper proposed a simple method for WM and GM extraction form magnetic resonance imaging (MRI) of brain. The proposed methods based on binarization, wavelet decomposition, and convexhull produce very effective results in the context of visual inspection and as well as quantifiably. It tested on three different (Transvers, Sagittal, Coronal) types of MRI of brain image and the validation of experiment indicate accurate detection and segmentation of the interesting structures or particular region of MRI of brain image.

Lijiang Tourism Prediction Based on the Gray Dynamic GM Model and Computer Simulation

[Objective] Taken the Linjiang tourism as an example, tourism forecast system was established, difficulties related to the work of tourist area were solved. [Method] Dynamic predicted response model of Lijiang tourism market was established, through the gray correlation model GM (1, 1) and time-series method, using a computer simulation program for the actual model of operation, Lijiang tourism prospects were predicted and predicting results were evaluated. [Result] Total revenue of model gray parameter of Lijiang tourism a= 0.572 3 from 2009 to 2011, internal control parameters u=0.393 7, x(t+1) =-0.563 3exp(-0.572 3t)+0.688 0; total reception numbers of model gray parameter of Lijiang tourism a = 0.125 6, internal control parameters u = 344. 326 0, x(t+1)=3 102.483 5 exp(0.125 6 t)-2 741.283 5. Test results of two models showed that fitting degrees were good, and at the same time predicted that total revenue of Lijiang tourism reached 13 000 000 000, and total reception numbers reached 8 800 000. [Conclusion] This predicted system can carry out precision forecast for other tourist areas when cannot get all the information.

Effects of electrostimulation and administration of succinylcholine on the expression of Fos protein in mesencephalic periaqueductal gray matter of rats after simulated weightlessness

BACKGROUND： Expression of Fos in neurons of periaqueductal gray （PAG） is used to reflect the excitability. However, changes of expression of Fos in neurons of PAG are caused by injured electrostimulation after simulated weightlessness, and the relationship between pretreatment and injection of succinylcholine has not been determined yet. OBJECTIVE ： To investigate the changes of expression of Fos in PAG induced by injured electrostimulation pretreatment and injection of succinylcholine at 2 weeks after simulated weightlessness.DESIGN： Observational and controlled animal study.SETTING： Department of Physiology, Medical School, Xi＇an Jiaotong University; Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education. MATERIALS： A total of 24 adult female SD rats, of clean grade and weighing 180-220 g, were selected in this study. METHODS： The experiment was completed in the Experimental Animal Center of Xi＇an Jiaotong University.① All rats were randomly divided into 2 groups according to body mass： simulated weightlessness group and control group with 12 in each group. And then, each group was also divided into 3 subgroups： electrostimulation group, succinylcholine-pretreatment group and succinylcholine-injection group with 4 in each subgroup. ②The model of weightlessness was simulated by tail-suspended female rats, which were described and modified by Cheng Jie. Rats in normal control group were given the same interventions as simulated weightlessness group except for tail-suspended. ③ Experimental method： The rats in electrostimulation group were given nociceptive stimulus by a pair of subcutaneous electrodes inserted into 1 and 5 claw of left hindlimb. The stimulus （current： 10 mA; duration： 1 ms; interval： 1 s） lasted for 30 minutes. The rats in succinylcholine-pretreatment group received stimulus after intravenous administration of succinylcholine, rats in succinylcholine-injection group were not given stimulus, just received succinylcholine. ④ All rats were perfused and fixed after 2 hours from the end of stimulation. The brains were removed, and serial frozen sections of midbrain were stained using immunocytochemical method, observed and taken photos under light-microscope. The number and morphological characters of Fos-immunoreactive （Fos-IR） neurons in ventrolateral part of PAG were investigated. MAIN OUTCOME MEASURES： The alterations in number and morphological characters of Fos-IR neurons in ventrolateral PAG of all rats.RESULTS： A total of 24 rats were involved in the final analysis. ① The morphological changes of Fos-IR neurons： The expressions of Fos in ventrolateral part of PAG were observed in both control and simulated weightlessness groups rats after being given nociceptive stimulus. As compared with control group, Fos-IR neurons in simulated weightlessness group were dyed lightly, cellular integrity was impaired, and cellular verge was unclear. ② The numbers of Fos-IR neurons： In control group, the numbers of Fos-IR neurons in ventrolateral part of PAG in simulated weightlessness group were obviously lower than succinylcholine-pretreatment group, but obviously higher than succinylcholine-injection group （46.94±3.38, 71.06±8.96 and 35.04±4.62, respectively, P 〈 0.05）. In 14-day simulated weightlessness group, the numbers of Fos-IR neurons in electrostimulation group were also obviously lower than succinylcholine-pretreatment group, and obviously higher than succinylcholine-injection group （27.77±3.27, 32.91±2.99 and 11.75±1.00, respectively, P 〈 0.05）. The numbers of Fos-IR neurons in all subgroups in control group were obviously higher than those subgroups in simulated weightlessness group. Compared with electrostimulation group, the percentage of expression of Fos in ventrolateral part of PAG responsed to nociceptive stimulus after administration of succinylcholine （SCH） was increased to 51.83% in control group and 18.51% in simulated weightlessness group.CONCLUSION ：① The expression of Fos in neurons in ventrolateral part of PAG were increased by the pretreatment of SCH before nociceptive stimulus.② Nociceptive stimulus could increase the expression of Fos in neurons in ventrolateral part of PAG. ③ The numbers of Fos-IR neurons in ventrolateral part of PAG were decreased obviously after 2-week simulated weightlessness.

Hippocampus Gray Matter Atrophy Happens More Seriously in AD Female Patients

Hippocampus, an area of cortex that plays an important role in thinking, planning and remembering. In Alzheimer’s disease (AD), the hippocampus is one of the first areas of the brain to become shriveled and this leads to the memory less, damage in learning and declaration of emotional behaviors. In this paper, we investigate the effects of sex on hippocampus gray matter (HGM) atrophy in four groups of participants, namely, males with AD (M-AD, n = 34), age-matched normal male controls (M-NC, n = 34), females with AD (F-AD, n = 34), and age matched normal female controls (F-NC, n = 34) from ADNI dataset. In this regard, Analysis of variance (ANOVA) is employed to compare means of HGM differences among groups. The statistical results obtained by ANOVA show that the distribution of HGM atrophy is effected by sex. Also there was a significant diagnosis with higher severity in the F-AD compared to M-AD. The AD studies based on the sex may help to figure out the root of AD mechanisms and poten-tially can be used as an imaging marker for the studies of AD in the future.

The Gray-Markov GM （1, 1） prediction model Optimal Allocation of Equipment Maintenance Personnel Research based on Difference Method

Based on the situation that the statistic of the missile facilities＇ stability was small, and the conventional big example preview method was no longer of use. So, this article used the gray GM （1, 1） model to preview a facility＇ s stability .The gray GM （1, 1） model doesn＇ t need a large number of example statistics, and it is also accurate, so this model solved the problem in the analyze and preview of the stability of the missile＇ s electronic facility system, and it has possibility to imply to engineering use.

Belly fat is Linked with lower volumes of gray matter

Belly fat has long been thought to be particularly bad for your heart, but now, a new study adds more evidence to the idea that it may also be bad for your brain. The study, from the United Kingdom, found that people who were obese and had a high waist-to-hip ratio (a measure of belly fat) had slightly lower brain volumes, on average, compared with people who were a healthy weight. Specifically, belly fat was linked with lower volumes of gray matter, the brain tissue that contains nerve cells.