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BACKGROUND: Endothelial cell TRPV4 (transient receptor potential vanilloid 4) channels provide a control point that is pivotal in regulating blood vessel diameter by mediating the Ca2+-dependent release of endothelial-derived vasoactive factors. In hypertension, TRPV4-mediated control of vascular function is disrupted, but the underlying mechanisms and precise physiological consequences remain controversial. METHODS: Here, using a comprehensive array of methodologies, endothelial TRPV4 channel function was examined in intact mesenteric resistance arteries from normotensive Wistar-Kyoto and spontaneously hypertensive rats. RESULTS: Our results show there is a notable shift in vascular reactivity in hypertension characterized by enhanced endothelium-dependent vasodilation at low levels of TRPV4 channel activation. However, at higher levels of TRPV4 activity, this vasodilatory response is reversed, contributing to the aberrant vascular tone observed in hypertension. The change in response, from dilation to constriction, was accompanied by a shift in intracellular Ca2+ signaling modalities arising from TRPV4 activity. Oscillatory TRPV4-evoked IP3 (inositol triphosphate)-mediated Ca2+ release, which underlies dilation, decreased, while the contraction inducing sustained Ca2+ rise, arising from TRPV4-mediated Ca2+ influx, increased. Our findings also reveal that while the sensitivity of endothelial cell TRPV4 to activation was unchanged, expression of the channel is upregulated and IP3 receptors are downregulated in hypertension. CONCLUSIONS: These data highlight the intricate interplay between endothelial TRPV4 channel expression, intracellular Ca2+ signaling dynamics, and vascular reactivity. Moreover, the data support a new unifying hypothesis for the vascular impairment that accompanies hypertension. Specifically, endothelial cell TRPV4 channels play a dual role in modulating blood vessel function in hypertension. [ABSTRACT FROM AUTHOR]

Background and Purpose: The single layer of cells lining all blood vessels, the endothelium, is a sophisticated signal co‐ordination centre that controls a wide range of vascular functions including the regulation of blood pressure and blood flow. To co‐ordinate activities, communication among cells is required for tissue level responses to emerge. While a significant form of communication occurs by the propagation of signals between cells, the mechanism of propagation in the intact endothelium is unresolved. Experimental Approach: Precision signal generation and targeted cellular manipulation was used in conjunction with high spatiotemporal mesoscale Ca2+ imaging in the endothelium of intact blood vessels. Key Results: Multiple mechanisms maintain communication so that Ca2+ wave propagation occurs irrespective of the status of connectivity among cells. Between adjoining cells, regenerative IP3‐induced IP3 production transmits Ca2+ signals and explains the propagated vasodilation that underlies the increased blood flow accompanying tissue activity. The inositide is itself sufficient to evoke regenerative phospholipase C‐dependent Ca2+ waves across coupled cells. None of gap junctions, Ca2+ diffusion or the release of extracellular messengers is required to support this type of intercellular Ca2+ signalling. In contrast, when discontinuities exist between cells, ATP released as a diffusible extracellular messenger transmits Ca2+ signals across the discontinuity and drives propagated vasodilation. Conclusion and Implications: These results show that signalling switches underlie endothelial cell‐to‐cell signal transmission and reveal how communication is maintained in the face of endothelial damage. The findings provide a new framework for understanding wave propagation and cell signalling in the endothelium. [ABSTRACT FROM AUTHOR]

BackgroundLocation-based augmented reality (AR) games, such as Pokémon GO and Harry Potter: Wizards Unite, have been shown to have a beneficial impact on the physical activity, social connectedness, and mental health of their players. In March 2020, global social distancing measures related to the COVID-19 pandemic prompted the AR games developer Niantic Inc to implement several changes to ensure continued player engagement with Pokémon GO and Harry Potter: Wizards Unite. We sought to examine how the physical and mental well-being of players of these games were affected during the unprecedented COVID-19 restriction period as well as how their video game engagement was affected. ObjectiveThe aims of this study were to examine the impact of COVID-19–related social restrictions on the physical and mental well-being of AR game players; to examine the impact of COVID-19–related social restrictions on the use of video games and motivations for their use; and to explore the potential role of AR games (and video games in general) in supporting well-being during COVID-19–related social restrictions. MethodsA mixed methods web-based self-reported survey was conducted in May 2020, during which COVID-19–related social restrictions were enforced in many countries. Participants were recruited on the web via four subreddits dedicated to Pokémon GO or Harry Potter: Wizards Unite. Data collected included quantitative data on demographics, time spent playing video games, physical activity, and mental health; qualitative data included motivations to play and the impact of video games on mental health during COVID-19 lockdown. ResultsWe report results for 2004 participants (1153/1960 male, 58.8%, average age 30.5 years). Self-reported physical activity during COVID-19–related social restrictions significantly decreased from 7.50 hours per week on average (SD 11.12) to 6.50 hours (SD 7.81) (P

The editorial discusses the importance of early and accurate diagnosis of Parkinson's disease (PD) through neuroimaging, focusing on the N1 sign as a promising biomarker. Advanced MRI techniques allow visualization of the N1 sign, which reflects the loss of dopaminergic neurons in the substantia nigra pars compacta. Wang et al. present a deep learning-based approach to identify the N1 sign on susceptibility-weighted imaging, highlighting the potential for automated segmentation and improved diagnostic accuracy in PD research. [Extracted from the article]

This multimethod study provides detailed information about the friendships of 87 children (76% boys) with ADHD and 46 comparison children aged 7-13 years. The methods included parent and teacher ratings, self-report measures and direct observation of friends' dyadic behaviors in three structured analogue tasks. Results indicated that, in contrast with comparison children, children with ADHD had friends with high levels of ADHD and oppositional symptoms; they perceived fewer positive features and more negative features, and were less satisfied in their friendships. Observational data indicated that children with ADHD performed both more legal and more illegal maneuvers than comparison children in a fast-paced competitive game. While negotiating with their friends, children with ADHD made more insensitive and self-centered proposals than comparison children. In dyads consisting of one child with ADHD and one typically developing child, children with ADHD were often more dominant than their friends.

Arteries and veins are lined by nonproliferating endothelial cells that play a critical role in regulating blood flow. Endothelial cells also regulate tissue perfusion, metabolite exchange, and thrombosis. It is thought that endothelial cells rely on ATP generated via glycolysis, rather than mitochondrial oxidative phosphorylation, to fuel each of these energy-demanding processes. However, endothelial metabolism has mainly been studied in the context of proliferative cells, and little is known about energy production in endothelial cells within the fully formed vascular wall. Using intact arteries isolated from rats and mice, we show that inhibiting mitochondrial respiration disrupts endothelial control of vascular tone. Basal, mechanically activated, and agonist-evoked calcium activity in intact artery endothelial cells are each prevented by inhibiting mitochondrial ATP synthesis. Agonist-evoked calcium activity was also inhibited by blocking the transport of pyruvate, the master fuel for mitochondrial energy production, through the mitochondrial pyruvate carrier. The role for mitochondria in endothelial cell energy production is independent of species, sex, or vascular bed. These data show that a mitochondrial ATP supply is necessary for calcium-dependent, nitric oxide-mediated endothelial control of vascular tone, and identifies the critical role of endothelial mitochondrial energy production in fueling perfused blood vessel function. [ABSTRACT FROM AUTHOR]

This article discusses the challenges of identifying structural correlates of epilepsy using conventional MRI sequences. To diagnose certain types of epilepsy, such as juvenile myoclonic epilepsy (JME) and epilepsy with generalized tonic-clonic seizures alone (GTCA), an MRI scan must be normal. However, differentiating between JME and GTCA can be difficult due to similar clinical presentations and electroencephalographic findings. The study presented in the article proposes a radiomics-based method to differentiate between JME and GTCA and predict favorable clinical outcomes. The study analyzes MRI scans of JME and GTCA patients and identifies important radiomics features in the striatum, thalamus, and white matter of the cerebrum and cerebellum. While the study has limitations and requires external validation, it represents an important step in applying radiomics to epilepsy and normal-appearing imaging studies. The use of explainable machine learning techniques, such as SHAP analysis, shows promise in integrating successful radiomics models into clinical practice. The article raises the question of whether radiologists can be trained to interpret imaging studies in a similar way to computer models. [Extracted from the article]

Background and Purpose: Ca2+ influx via TRPV4 channels triggers Ca2+ release from the IP3‐sensitive internal store to generate repetitive oscillations. Although mitochondria are acknowledged regulators of IP3‐mediated Ca2+ release, how TRPV4‐mediated Ca2+ signals are regulated by mitochondria is unknown. We show that depolarised mitochondria switch TRPV4 signalling from relying on Ca2+‐induced Ca2+ release at IP3 receptors to being independent of Ca2+ influx and instead mediated by ATP release via pannexins. Experimental Approach TRPV4‐evoked Ca2+ signals were individually examined in hundreds of cells in the endothelium of rat mesenteric resistance arteries using the indicator Cal520. Key Results: TRPV4 activation with GSK1016790A (GSK) generated repetitive Ca2+ oscillations that required Ca2+ influx. However, when the mitochondrial membrane potential was depolarised, by the uncoupler CCCP or complex I inhibitor rotenone, TRPV4 activation generated large propagating, multicellular, Ca2+ waves in the absence of external Ca2+. The ATP synthase inhibitor oligomycin did not potentiate TRPV4‐mediated Ca2+ signals. GSK‐evoked Ca2+ waves, when mitochondria were depolarised, were blocked by the TRPV4 channel blocker HC067047, the SERCA inhibitor cyclopiazonic acid, the PLC blocker U73122 and the inositol trisphosphate receptor blocker caffeine. The Ca2+ waves were also inhibited by the extracellular ATP blockers suramin and apyrase and the pannexin blocker probenecid. Conclusion and Implications: These results highlight a previously unknown role of mitochondria in shaping TRPV4‐mediated Ca2+ signalling by facilitating ATP release. When mitochondria are depolarised, TRPV4‐mediated release of ATP via pannexin channels activates plasma membrane purinergic receptors to trigger IP3‐evoked Ca2+ release. [ABSTRACT FROM AUTHOR]