77 research outputs found
Mapping of multiple muscles with transcranial magnetic stimulation: Absolute and relative test-retest reliability
The spatial accuracy of transcranial magnetic stimulation (TMS) may be as small as a few millimeters. Despite such great potential, navigated TMS (nTMS) mapping is still underused for the assessment of motor plasticity, particularly in clinical settings. Here, we investigate the within‐limb somatotopy gradient as well as absolute and relative reliability of three hand muscle cortical representations (MCRs) using a comprehensive grid‐based sulcus‐informed nTMS motor mapping. We enrolled 22 young healthy male volunteers. Two nTMS mapping sessions were separated by 5–10 days. Motor evoked potentials were obtained from abductor pollicis brevis (APB), abductor digiti minimi, and extensor digitorum communis. In addition to individual MRI‐based analysis, we studied normalized MNI MCRs. For the reliability assessment, we calculated intraclass correlation and the smallest detectable change. Our results revealed a somatotopy gradient reflected by APB MCR having the most lateral location. Reliability analysis showed that the commonly used metrics of MCRs, such as areas, volumes, centers of gravity (COGs), and hotspots had a high relative and low absolute reliability for all three muscles. For within‐limb TMS somatotopy, the most common metrics such as the shifts between MCR COGs and hotspots had poor relative reliability. However, overlaps between different muscle MCRs were highly reliable. We, thus, provide novel evidence that inter‐muscle MCR interaction can be reliably traced using MCR overlaps while shifts between the COGs and hotspots of different MCRs are not suitable for this purpose. Our results have implications for the interpretation of nTMS motor mapping results in healthy subjects and patients with neurological conditions
Role of CT Angiography in Detection of Extracranial Carotid and Vertebral Artery Disease in Patients With Acutely Ruptured Intracranial Aneurysms
Introduction: Computed tomography (CT) and CT angiography are standard imaging modalities for suspected acute intracerebral hemorrhage due to ruptured intracranial aneurysms. In this clinical setting, several protocols of computed tomography and CT angiography may be implemented. The standard CT angiography protocol is limited to intracranial vessels. The extended protocol may also include carotid and vertebral arteries and the aortic arch.Objective: To define the CT angiography role in detection of extracranial carotid and vertebral artery disease and clinical significance of this method for patients with suspected acute intracerebral hemorrhages due to ruptured intracranial aneurysms.Materials and methods: The study included 275 neurosurgical patients with acute nontraumatic intracranial hemorrhages due to ruptured intracranial aneurysms who were treated in Scientific Research Institute – Ochapovsky Regional Clinical Hospital No. 1 (Krasnodar, Russian Federation) from September 2017 to August 2020. Computed tomography and CT angiography were performed in all patients. The scanned area included both intracranial and extracranial arteries (an arch-to-vertex angiogram) to detect extracranial carotid and vertebral artery diseases such as stenoses, occlusions, tortuosity, and hypoplasia.Results: Atherosclerosis of internal carotid and vertebral arteries was diagnosed in 95 patients (34.5% of the total number of patients included in the study). In 13 (4.7%) patients these stenoses were hemodynamically significant. We identified a high frequency of tortuous carotid and vertebral arteries (122 cases, 44.3%) and vertebral artery hypoplasia (59 cases, 21.5%). The carotid and vertebral artery stenoses and congenital anomalies of vertebral arteries (however, not of carotid arteries) were associated with a higher incidence of unfavorable outcomes after endovascular treatment of intracranial aneurysms.Conclusions: The optimal CT angiography protocol for acute nontraumatic intracranial hemorrhage should focus on the arteries of the head and neck (up to the aortic arch). This protocol shows higher detection rate of concomitant anomalies of carotid and vertebral arteries. These findings are important for planning and successful performance of endovascular treatment for intracranial aneurysms
EmoEye: айтрекер и биометрическая база данных для распознавания эмоций
Original manuscript received February 01, 2023. Revised manuscript accepted February 20, 2023.Emotion recognition using Machine Learning algorithms is often used both in science and commerce. Responding to the demand for deep learning techniques of automatic emotion detection using biological signals and our own business needs as a neuromarketing laboratory, we created a large dataset of eye tracking and biometrics data suitable for emotion recognition tasks. The EmoEye database sample consisted of 200 people (147 women, 49 men, 4 non-binary individuals; 27.46 ± 11.45 years old). Each respondent was asked to view 316 images from the Open Affective Standardized Image Set (OASIS) and rate them on arousal and valence scales from the Self-Assessment Manikin questionnaire. Eye tracking, galvanic skin response (GSR), and photoplethysmogram were recorded throughout the experiment. Demographic data was also collected for each respondent. The image ratings on the valence scale did not differ statistically from the standard ratings of the corresponding images for the original stimulus base. The overall distribution trends of ratings on both scales for different categories of images were similar for standard ratings and ratings obtained from our respondents. As a result of this study, a corpus of GSR, heart rate variability and eye movement reactions data (fixation coordinates; fixation duration; average pupil size for the right and left eye) was compiled and successfully trained on a multimodal neural network algorithm within our laboratory and is ready for further implementation.Распознавание эмоций с помощью алгоритмов машинного обучения часто используется как в науке, так и в коммерции. С помощью методов глубокого обучения для автоматического обнаружения эмоций с использованием биологических сигналов мы подготовили набор данных для айтрекинга и биометрических данных, подходящих для задач распознавания эмоций. Выборка базы данных EmoEye состояла из 200 человек (147 женщин, 49 мужчин, 4 небинарных индивидуума; 27,46 ± 11,45 лет). Каждому респонденту было предложено просмотреть 316 изображений из открытого аффективного стандартизированного набора изображений (OASIS) и оценить их по шкалам возбуждения и валентности из опросника «Манекен самооценки». Отслеживание взгляда, кожно-гальваническая реакция (GSR) и фотоплетизмограмма регистрировались на протяжении всего эксперимента. Также были собраны демографические данные по каждому респонденту. Оценки изображений по валентной шкале статистически не отличались от стандартных оценок соответствующих изображений для исходной базы стимулов. Общие тенденции распределения оценок по обеим шкалам для разных категорий изображений были одинаковыми для стандартных оценок и оценок, которые были даны нашими респондентами. В результате исследования в рамках нашей лаборатории были получены данные о GSR, вариабельности сердечного ритма и реакциях движения глаз (координаты фиксации; длительность фиксации; средний размер зрачка для правого и левого глаза), которые были успешно реализованы на основе мультимодального нейросетевого алгоритма и готовы к внедрению
Gene Expression Rhythms in the Mussel Mytilus galloprovincialis (Lam.) across an Annual Cycle
Seasonal environmental changes may affect the physiology of Mytilus
galloprovincialis (Lam.), an intertidal filter-feeder bivalve
occurring commonly in Mediterranean and Atlantic coastal areas. We investigated
seasonal variations in relative transcript abundance of the digestive gland and
the mantle (gonads) of males and females. To identify gene expression trends
– in terms of relative mRNA abundance- we used a medium-density cDNA
microarray (1.7 K probes) in dual-color competitive hybridization analyses.
Hierarchical clustering of digestive gland microarray data showed two main
branches, distinguishing profiles associated with the “hot” months
(May–August) from the other months. Genes involved in chitin metabolism,
associated with mussel nutrition and digestion showed higher mRNA levels during
summer. Moreover, we found different gene transcriptomic patterns in the
digestive glands of males when compared to females, during the four stages of
mussel gonadal development. Microarray data from gonadal transcripts also
displayed clear patterns during the different developmental phases respect to
the resting period (stage I) with peak relative mRNA abundance at the ripe phase
(stage III) for both sexes. These data showed a clear temporal pattern in
transcriptomic profiles of mussels sampled over an annual cycle. Physiological
response to thermal variation, food availability, and reproductive status across
months may contribute to variation in relative mRNA abundance
Network Analysis of Oyster Transcriptome Revealed a Cascade of Cellular Responses during Recovery after Heat Shock
Oysters, as a major group of marine bivalves, can tolerate a wide range of natural and anthropogenic stressors including heat stress. Recent studies have shown that oysters pretreated with heat shock can result in induced heat tolerance. A systematic study of cellular recovery from heat shock may provide insights into the mechanism of acquired thermal tolerance. In this study, we performed the first network analysis of oyster transcriptome by reanalyzing microarray data from a previous study. Network analysis revealed a cascade of cellular responses during oyster recovery after heat shock and identified responsive gene modules and key genes. Our study demonstrates the power of network analysis in a non-model organism with poor gene annotations, which can lead to new discoveries that go beyond the focus on individual genes
Selective Interaction of Syntaxin 1A with KCNQ2: Possible Implications for Specific Modulation of Presynaptic Activity
KCNQ2/KCNQ3 channels are the molecular correlates of the neuronal M-channels, which play a major role in the control of neuronal excitability. Notably, they differ from homomeric KCNQ2 channels in their distribution pattern within neurons, with unique expression of KCNQ2 in axons and nerve terminals. Here, combined reciprocal coimmunoprecipitation and two-electrode voltage clamp analyses in Xenopus oocytes revealed a strong association of syntaxin 1A, a major component of the exocytotic SNARE complex, with KCNQ2 homomeric channels resulting in a ∼2-fold reduction in macroscopic conductance and ∼2-fold slower activation kinetics. Remarkably, the interaction of KCNQ2/Q3 heteromeric channels with syntaxin 1A was significantly weaker and KCNQ3 homomeric channels were practically resistant to syntaxin 1A. Analysis of different KCNQ2 and KCNQ3 chimeras and deletion mutants combined with in-vitro binding analysis pinpointed a crucial C-terminal syntaxin 1A-association domain in KCNQ2. Pull-down and coimmunoprecipitation analyses in hippocampal and cortical synaptosomes demonstrated a physical interaction of brain KCNQ2 with syntaxin 1A, and confocal immunofluorescence microscopy showed high colocalization of KCNQ2 and syntaxin 1A at presynaptic varicosities. The selective interaction of syntaxin 1A with KCNQ2, combined with a numerical simulation of syntaxin 1A's impact in a firing-neuron model, suggest that syntaxin 1A's interaction is targeted at regulating KCNQ2 channels to fine-tune presynaptic transmitter release, without interfering with the function of KCNQ2/3 channels in neuronal firing frequency adaptation
Metabolic responses to high pCO2 conditions at a CO2 vent site in juveniles of a marine isopod species assemblage
We are starting to understand the relationship between metabolic rate responses and species' ability to respond to exposure to high pCO2. However, most of our knowledge has come from investigations of single species. The examination of metabolic responses of closely related species with differing distributions around natural elevated CO2 areas may be useful to inform our understanding of their adaptive significance. Furthermore, little is known about the physiological responses of marine invertebrate juveniles to high pCO2, despite the fact they are known to be sensitive to other stressors, often acting as bottlenecks for future species success. We conducted an in situ transplant experiment using juveniles of isopods found living inside and around a high pCO2 vent (Ischia, Italy): the CO2 'tolerant' Dynamene bifida and 'sensitive' Cymodoce truncata and Dynamene torelliae. This allowed us to test for any generality of the hypothesis that pCO2 sensitive marine invertebrates may be those that experience trade-offs between energy metabolism and cellular homoeostasis under high pCO2 conditions. Both sensitive species were able to maintain their energy metabolism under high pCO2 conditions, but in C. truncata this may occur at the expense of [carbonic anhydrase], confirming our hypothesis. By comparison, the tolerant D. bifida appeared metabolically well adapted to high pCO2, being able to upregulate ATP production without recourse to anaerobiosis. These isopods are important keystone species; however, given they differ in their metabolic responses to future pCO2, shifts in the structure of the marine ecosystems they inhabit may be expected under future ocean acidification conditions
Effect of cadmium on the defense response of Pacific oyster Crassostrea gigas to Listonella anguillarum challenge
Transcriptional profile of breast muscle in heat stressed layers is similar to that of broiler chickens at control temperature
Abstract Background In recent years, the commercial importance of changes in muscle function of broiler chickens and of the corresponding effects on meat quality has increased. Furthermore, broilers are more sensitive to heat stress during transport and at high ambient temperatures than smaller egg-laying chickens. We hypothesised that heat stress would amplify muscle damage and expression of genes that are involved in such changes and, thus, lead to the identification of pathways and networks associated with broiler muscle and meat quality traits. Broiler and layer chickens were exposed to control or high ambient temperatures to characterise differences in gene expression between the two genotypes and the two environments. Results Whole-genome expression studies in breast muscles of broiler and layer chickens were conducted before and after heat stress; 2213 differentially-expressed genes were detected based on a significant (P < 0.05) genotype × treatment interaction. This gene set was analysed with the BioLayout Express3D and Ingenuity Pathway Analysis software and relevant biological pathways and networks were identified. Genes involved in functions related to inflammatory reactions, cell death, oxidative stress and tissue damage were upregulated in control broilers compared with control and heat-stressed layers. Expression of these genes was further increased in heat-stressed broilers. Conclusions Differences in gene expression between broiler and layer chickens under control and heat stress conditions suggest that damage of breast muscles in broilers at normal ambient temperatures is similar to that in heat-stressed layers and is amplified when broilers are exposed to heat stress. The patterns of gene expression of the two genotypes under heat stress were almost the polar opposite of each other, which is consistent with the conclusion that broiler chickens were not able to cope with heat stress by dissipating their body heat. The differentially expressed gene networks and pathways were consistent with the pathological changes that are observed in the breast muscle of heat-stressed broilers
Deciphering the molecular adaptation of the king scallop (Pecten maximus) to heat stress using transcriptomics and proteomics
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