Role of presynaptic glutamate receptors in Modulation of long term synaptic plasticity (LTP) in inhibitory synapes of visual pyramidal neuron after epilepsy: a whole cell patch clamp recording

Purpose: Results from animal models has pointed out that presynaptic NMDA (pre-NMDA) receptor is present in visual cortex and pre-NMDA has significant role in epilepsy. Therefore we have tested the role of pre-NMDA receptor for GABA-ergic transmission in the visual cortex in acute condition of epilepsy. Methods: Using the pilocarpine mouse model, visual cortical slices were prepared immediately after having seizure (Pilo.group), and spontaneous miniature IPSCs (miPSCs) were recorded from pyramidal neurons of layer II/III in visual cortex. Amplitudes and frequencies of miPSC were analyzed and compared with those in age-matched saline-injected controls. Results: Frequency of miniature IPSCs (miPSCs) were significantly increased in saline controls compared to Pilo. Amplitude has no significant difference among groups using NBQX only or NBQX and MK801 combined use. Conclusion: In acute condition of epilepsy, there is no significant role of presynaptic NMDA receptor for GABA-ergic neurotransmitter release which is a indicator of long term potentiation (L TP) of inhibitory synapses

Diffusion Weighted Imaging and Grading of Brain Tumours

Background: Most prevalent primary cerebral tumours are meningiomas. The other frequent intracranial tumours are pituitary adenomas, which are benign, and gliomas, which are intra-axial brain tumours. The objective of this study is to understand the importance of DW MRI imaging with standard b-value in differentiating presurgical grading of the brain tumour.Design: A total of 24 DWI patients, including 12 meningiomas, 8 gliomas, and 4 pituitary adenomas, were included in this retrospective analysis.Method: The Stejskal-Tanner equation is used to analyse the ADCmean, ADCmin, and ADCmax values from the healthy and tumour core that are obtained out from area of interest (ROI).Result: The ADCmean value of Gliomas ranges from 0.09 x 10-3 mm2s-1 to 0.99 x 10-3 mm2s-1 with a median value of 0.25 x 10-3 mm2s-1. ADCmean value 1.82 x 10-3 mm2/s (sensitivity: 67%. Specificity: 81.8%) and 0.94 x 10-3 mm2/s (sensitivity: 75%. specificity: 81.3%) can discriminate grade II –IV meningioma from grade II-IV glioma.Conclusion: The ADC and its threshold levels offer crucial details on the grades, consistency, and characterization of tumour, aiding accurate diagnosis and therapy

Single-trial extraction of event-related potentials (ERPs) and classification of visual stimuli by ensemble use of discrete wavelet transform with Huffman coding and machine learning techniques

BackgroundPresentation of visual stimuli can induce changes in EEG signals that are typically detectable by averaging together data from multiple trials for individual participant analysis as well as for groups or conditions analysis of multiple participants. This study proposes a new method based on the discrete wavelet transform with Huffman coding and machine learning for single-trial analysis of evenal (ERPs) and classification of different visual events in the visual object detection task.MethodsEEG single trials are decomposed with discrete wavelet transform (DWT) up to the level of decomposition using a biorthogonal B-spline wavelet. The coefficients of DWT in each trial are thresholded to discard sparse wavelet coefficients, while the quality of the signal is well maintained. The remaining optimum coefficients in each trial are encoded into bitstreams using Huffman coding, and the codewords are represented as a feature of the ERP signal. The performance of this method is tested with real visual ERPs of sixty-eight subjects.ResultsThe proposed method significantly discards the spontaneous EEG activity, extracts the single-trial visual ERPs, represents the ERP waveform into a compact bitstream as a feature, and achieves promising results in classifying the visual objects with classification performance metrics: accuracies 93.60, sensitivities 93.55, specificities 94.85, precisions 92.50, and area under the curve (AUC) 0.93 using SVM and k-NN machine learning classifiers.ConclusionThe proposed method suggests that the joint use of discrete wavelet transform (DWT) with Huffman coding has the potential to efficiently extract ERPs from background EEG for studying evoked responses in single-trial ERPs and classifying visual stimuli. The proposed approach has O(N) time complexity and could be implemented in real-time systems, such as the brain-computer interface (BCI), where fast detection of mental events is desired to smoothly operate a machine with minds

Assessing neuroplasticity using magnetoencephalography (MEG) in patient with left-temporo-parietal pilocytic astrocytomas treated with endoscopic surgery

Neuroplasticity has been subjected to a great deal of research in the last century. Recently, significant emphasis has been placed on the global effect of localized plastic changes throughout the central nervous system, and on how these changes integrate in a pathological context. The present study aimed to demonstrate the functional cortical reorganization before and after surgery using magnetoencephalography (MEG) in a participant with brain tumor. Results of Visual Evoked Magnetic Field (VEF) based on functional MEG study revealed significantly different of MEG N100 waveforms before and after surgery. Larger and additional new locations for visual activation areas after the surgery were found suggesting neuroplasticity. The present study highlight a physiological plasticity in a teenage brain and the alterations regarding neural plasticity and network remodeling described in pathological contexts in higher-order visual association areas

Observation of tumour-induced reorganization in structural and functional architecture of the brain in three pre-surgical patients with left frontal-temporal brain tumour: a combination of MEG, DTI and neuropsychological assessment

Visual function is mainly located within the bilateral hemisphere of the occipital lobes of the brain. However, our functional magnetoencephalography (MEG) result has demonstrated the reorganization of brain activity in the occipital area in patients with left-sided brain tumour. The results showed that brain laterality changes from bilateral to unilateral activation of the occipital area. Right occipital area (contralateral areas to the tumour), shows increase intensity of activation. Diffusion tensor imaging (DTI) with fibre tracking was performed to further investigate this brain laterality modification and the findings confirmed there is an alteration in the left hemisphere fibre optic tracts. This functional modification and changes of the brain laterality and optic tracts in the brain is suspected to be the result of tumour growth induced changes. The present observation will be discussed in term of the mechanism of tumour induced reorganization and changes with the corroborating evidence from MEG, DTI and neuropsychological assessment

Observation of auditory perceptual and visuo-spatial characteristic of a patient with hemangiopericytoma in occipital lobe: a magnetoencephalography (MEG) study

The present study discussed functional reorganization and alteration in respond to the slow-growing tumour, hemangiopericytoma in the occipital cortex. Visual evoked field (VEF) and auditory evoked field (AEF) using magnetoencephalography (MEG) was used to evaluate the source localization and brain activity. Results of VEF source localization show a typical brain waves. Brain activity of the occipital lobe demonstrate low activation in the ipsilateral to the tumour. However, result shows the activation on the contralateral hemisphere was high and bigger in activation volume. AEF result shows an identical source localization and both side of the temporal lobe are activated. This result suggests that there is a positive plasticity in auditory cortex and slow-growing tumour can induce functional reorganization and alteration to the brain

Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019

Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66–2·79) in 2000 to 2·31 (2·17–2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5–137·8) in 2000 to a peak of 139·6 million (133·0–146·9) in 2016. Global livebirths then declined to 135·3 million (127·2–144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4–27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8–67·6) in 2000 to 73·5 years (72·8–74·3) in 2019. The total number of deaths increased from 50·7 million (49·5–51·9) in 2000 to 56·5 million (53·7–59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1–10·3) in 2000 to 5·0 million (4·3–6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0–6·3) in 2000 to 7·7 billion (7·5–8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1–60·8) in 2000 to 63·5 years (60·8–66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019

Motor learning of hands with auditory cue in patients with Parkinson’s disease

In the present research, changes in motor cortex function were observed in relation to repetitive, voluntary thumb movement (training) in patients with Parkinson’s disease (PD) and normal control subjects. Changes in the direction of thumb movement due to motor evoked potential (MEP) by transcranial magnetic stimulation (TMS), after motor training with and without rhythmic sound, were measured using a strain gauge for 12 patients with PD and 9 normal control subjects. PD patients who experienced the freezing phenomena showed poor change in direction of TMS-induced movement after self-paced movement; however, marked change in direction of TMS-induced movement was observed after training with auditory cue. PD patients who had not experienced the freezing phenomena showed positive effects with the auditory cue, producing similar results as the normal control subjects. Two routes for voluntary movement are available in the nervous system. The decreased function of basal ganglia due to PD impaired the route from the basal ganglia to the supplementary motor cortex. These data suggest that the route from sensory input to cerebellum to premotor cortex could compensate for the decreased function of the route via the basal ganglia to the premotor cortex. Once change in the motor cortex occurred, such change persisted even after the interruption of training. These phenomena suggest that motor memory can be stored in the motor cortex