Current methodology used to investigate how shifts in brain states associated with regional cerebral blood volume (CBV) change in deep brain areas, are limited by either the spatiotemporal resolution of the CBV techniques, and/or compatibility with electrophysiological recordings; particularly in relation to spontaneous brain activity and the study of individual events. Additionally, infraslow brain signals (<0.1 Hz), including spreading depolarisations, DC-shifts and infraslow oscillations (ISO), are poorly captured by traditional AC-coupled electrographic recordings; yet these very slow brain signals can profoundly change CBV.
View Article and Find Full Text PDFThe movement of ions in and out of neurons can exert significant effects on neighboring cells. Here we report several experimentally important consequences of activation of the optogenetic chloride pump, halorhodopsin. We recorded extracellular K concentration ([K]) in neocortical brain slices prepared from young adult mice (both sexes) which express halorhodopsin in pyramidal cells.
View Article and Find Full Text PDFWe propose that to fully understand biological mechanisms underlying pathological brain activity with transitions (e.g., into and out of seizures), wide-bandwidth electrophysiological recordings are important.
View Article and Find Full Text PDFMapping the entire frequency bandwidth of brain electrophysiological signals is of paramount importance for understanding physiological and pathological states. The ability to record simultaneously DC-shifts, infraslow oscillations (<0.1 Hz), typical local field potentials (0.
View Article and Find Full Text PDFThis technical note introduces adiabatic dynamic causal modelling, a method for inferring slow changes in biophysical parameters that control fluctuations of fast neuronal states. The application domain we have in mind is inferring slow changes in variables (e.g.
View Article and Find Full Text PDFIndividuals who have Down syndrome (caused by trisomy of chromosome 21), have a greatly elevated risk of early-onset Alzheimer's disease, in which amyloid-β accumulates in the brain. Amyloid-β is a product of the chromosome 21 gene APP (amyloid precursor protein) and the extra copy or 'dose' of APP is thought to be the cause of this early-onset Alzheimer's disease. However, other chromosome 21 genes likely modulate disease when in three-copies in people with Down syndrome.
View Article and Find Full Text PDFThe development of experimental methodology utilizing graphene micro-transistor arrays to facilitate and advance translational research into cortical spreading depression (CSD) in the awake brain.CSDs were reliably induced in awake nontransgenic mice using optogenetic methods. High-fidelity DC-coupled electrophysiological mapping of propagating CSDs was obtained using flexible arrays of graphene soultion-gated field-effect transistors (gSGFETs).
View Article and Find Full Text PDFMast cells play a significant role in the pathophysiology of many diverse diseases such as asthma and pulmonary fibrosis. Ca2+ influx is essential for mast cell degranulation and release of proinflammatory mediators, while Mg2+ plays an important role in cellular homeostasis. The channels supporting divalent cation influx in human mast cells have not been identified, but candidate channels include the transient receptor potential melastatin (TRPM) family.
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