Biology subjects

Shamsi, F.

Publications and source records attributed to Shamsi, F..

2 recordsLinked to original sources

bioRxiv2020

Early Classification of Motor Tasks Using Dynamic Functional Connectivity Graphs from EEG

ObjectiveClassification of electroencephalography (EEG) signals with high accuracy using short recording intervals has been a challenging problem in developing brain computer interfaces (BCIs). This paper presents a novel feature extraction method for EEG recordings to tackle this problem. ApproachThe proposed approach is based on the concept that the brain functions in a dynamic manner, and utilizes dynamic functional connectivity graphs. The EEG data is first segmented into intervals during which functional networks sustain their connectivity. Functional connectivity networks for each identified segment are then localized, and graphs are constructed, which will be used as features. To take advantage of the dynamic nature of the generated graphs, a Long Short Term Memory (LSTM) classifier is employed for classification. Main resultsFeatures extracted from various durations of post-stimulus EEG data associated with motor execution and imagery tasks are used to test the performance of the classifier. Results show an average accuracy of 85.32% about only 500 ms after stimulus presentation. SignificanceOur results demonstrate, for the first time, that using the proposed feature extraction method, it is possible to classify motor tasks from EEG recordings using a short interval of the data in the order of hundreds of milliseconds (e.g. 500 ms).This duration is considerably shorter than what has been reported before. These results will have significant implications for improving the effectiveness and the speed of BCIs, particularly for those used in assistive technologies.

neuroscience↗

bioRxiv2020

Vascular smooth muscle-derived TRPV1-expressing progenitors are a new source of cold-induced thermogenic adipocytes

Brown adipose tissue (BAT) functions in energy expenditure in part due its role in thermoregulation. The prominent capacity of BAT to enhance fuel utilization and energy expenditure makes it an attractive target for treating obesity and metabolic disorders. Prolonged cold exposure induces de novo recruitment of brown adipocytes and activates their thermogenic activity. However, the exact source of cold-induced brown adipocytes is not completely understood. In this study, we sought to investigate the cellular origin of cold-induced brown adipocytes using single-cell RNA sequencing. We identified two distinct types of adipocyte progenitors that contribute to de novo recruitment of brown adipocytes in response to cold challenge. One is the previously known Pdgfra-expressing mesenchymal progenitors and the other is a vascular smooth muscle-derived adipocyte progenitor (VSM-APC) population, which expresses the temperature-sensitive ion channel transient receptor potential cation channel subfamily V member 1 (Trpv1). Using flow cytometry and lineage tracing, we demonstrated that the Trpv1pos VSM-APCs were indeed distinct from the Pdgfrapos progenitors and could contribute to brown adipocytes with greater thermogenic potential. Together, these findings illustrate a landscape of thermogenic adipose niche at the single cell resolution and identify a new cellular origin for the development of brown adipocytes.Competing Interest StatementThe authors have declared no competing interest.View Full Text

developmental biology↗