CircLphn3 protects the blood-brain barrier in traumatic brain injury.

Circular RNAs (circRNAs) are a new and large group of non-coding RNA molecules that are abundantly expressed in the central nervous system. However, very little is known about their roles in traumatic brain injury. In this study, we firstly screened differentially expressed circRNAs in normal and injured brain tissues of mice after traumatic brain injury. We found that the expression of circLphn3 was substantially decreased in mouse models of traumatic brain injury and in hemin-treated bEnd.3 (mouse brain cell line) cells. After overexpressing circLphn3 in bEnd.3 cells, the expression of the tight junction proteins, ZO-1, ZO-2, and occludin, was upregulated, and the expression of miR-185-5p was decreased. In bEnd.3 cells transfected with miR-185-5p mimics, the expression of ZO-1 was decreased. Dual-luciferase reporter assays showed that circLphn3 bound to miR-185-5p, and that miR-185-5p bound to ZO-1. Additionally, circLphn3 overexpression attenuated the hemin-induced high permeability of the in vitro bEnd.3 cell model of the blood-brain barrier, while miR-185-5p transfection increased the permeability. These findings suggest that circLphn3, as a molecular sponge of miR-185-5p, regulates tight junction proteins' expression after traumatic brain injury, and it thereby improves the permeability of the blood-brain barrier. This study was approved by the Animal Care and Use Committee of Chongqing Medical University of China (approval No. 2021-177) on March 22, 2021.

Mindfulness meditation alters neural activity underpinning working memory during tactile distraction.

Evidence suggests that mindfulness meditation (MM) improves selective attention and reduces distractibility by enhancing top-down neural modulation. Altered P300 and alpha neural activity from MM have been identified and may reflect the neural changes that underpin these improvements. Given the proposed role of alpha activity in supressing processing of task-irrelevant information, it is theorised that altered alpha activity may underlie increased availability of neural resources in meditators. The present study investigated attentional function in meditators using a cross-modal study design, examining the P300 during working memory (WM) and alpha activity during concurrent distracting tactile stimuli. Thirty-three meditators and 27 healthy controls participated in the study. Meditators showed a more frontal distribution of P300 neural activity following WM stimuli (p = 0.005, η2 = 0.060) and more modulation of alpha activity at parietal-occipital regions between single (tactile stimulation only) and dual task demands (tactile stimulation plus WM task) (p < 0.001, η2 = 0.065). Additionally, meditators performed more accurately than controls (p = 0.038, η2 = 0.067). The altered distribution of neural activity concurrent with improved WM performance suggests greater attentional resources dedicated to task related functions, such as WM in meditators. Thus, meditation-related neural changes are likely multifaceted, involving both altered distribution and also amplitudes of brain activity, thereby enhancing attentional processes depending on task requirements.

An unusual cause of acute ischemic stroke: Adult Onset Still's Disease.

Adult Onset Still's Disease (AOSD) is a systemic inflammatory disease of unknown aetiology. The usual manifestations of AOSD are spiking fevers, arthritis, and an evanescent salmon-pink rash, with neurological manifestations occasionally described. Stroke is a rare manifestation of AOSD and the exact mechanism for stroke in AOSD remains unknown, although it has been hypothesized to be secondary to thrombocytosis or vasculitis. We present a case where acute ischemic stroke secondary to a floating internal carotid artery thrombus was an early manifestation of AOSD. The patient also had prolonged high spiking fevers, significant leucocytosis, arthralgias and transaminitis. He responded well to a high dose of oral corticosteroids and was eventually started on anticoagulation for secondary stroke prevention. To our knowledge, this is the first described case of arterial thrombosis associated with AOSD. We postulate that thrombocytosis, vasculitis and hypercoagulability from the underlying inflammatory state may have contributed to the ischemic stroke.