Publications by authors named "Alice Braga"

The disease's trajectory of Alzheimer disease (AD) is associated with and negatively correlated to hippocampal hyperexcitability. Here, we show that during the asymptomatic stage in a knockin (KI) mouse model of Alzheimer disease (APP; APPKI), hippocampal hyperactivity occurs at the synaptic compartment, propagates to the soma, and is manifesting at low frequencies of stimulation. We show that this aberrant excitability is associated with a deficient adenosine tone, an inhibitory neuromodulator, driven by reduced levels of CD39/73 enzymes, responsible for the extracellular ATP-to-adenosine conversion.

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  • Binodacarus tocantinensis sp. nov. and Rhodacarus emilianoi sp. nov. are two new species identified based on features of adult females found in soil and litter from the Cerrado biome in northern Brazil.
  • The study includes detailed morphology descriptions for these new species.
  • It also offers identification keys for distinguishing female species within the Binodacarus and Rhodacarus genera globally.
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  • Heart failure is a big health issue, and doctors are exploring new treatments like vagus nerve stimulation (VNS), which uses devices to help the heart.
  • A study on rats looked at how VNS affects the heart's genes and found 294 genes that changed when the vagus nerve was stimulated with light.
  • The results suggest that VNS can help the heart by influencing important processes like inflammation, protein production, and heart growth, showing that keeping the vagus nerve active might be good for heart health.
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Neuronal activity undergoes significant changes during vigilance states, accompanied by an accommodation of energy demands. While the astrocyte-neuron lactate shuttle has shown that lactate is the primary energy substrate for sustaining neuronal activity in multiple brain regions, its role in regulating sleep/wake architecture is not fully understood. Here we investigated the involvement of astrocytic lactate supply in maintaining consolidated wakefulness by downregulating, in a cell-specific manner, the expression of monocarboxylate transporters (MCTs) in the lateral hypothalamus of transgenic mice.

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Brain computation performed by billions of nerve cells relies on a sufficient and uninterrupted nutrient and oxygen supply. Astrocytes, the ubiquitous glial neighbours of neurons, govern brain glucose uptake and metabolism, but the exact mechanisms of metabolic coupling between neurons and astrocytes that ensure on-demand support of neuronal energy needs are not fully understood. Here we show, using experimental in vitro and in vivo animal models, that neuronal activity-dependent metabolic activation of astrocytes is mediated by neuromodulator adenosine acting on astrocytic A2B receptors.

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The brain requires an uninterrupted supply of oxygen and nutrients to support the high metabolic needs of billions of nerve cells processing information. In low oxygen conditions, increases in cerebral blood flow maintain brain oxygen delivery, but the cellular and molecular mechanisms responsible for dilation of cerebral blood vessels in response to hypoxia are not fully understood. This article presents a systematic review and analysis of data reported in studies of these mechanisms.

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The disease's trajectory of Alzheimer's disease (AD) is associated with and worsened by hippocampal hyperexcitability. Here we show that during the asymptomatic stage in a knock in mouse model of Alzheimer's disease (APP; APPKI), hippocampal hyperactivity occurs at the synaptic compartment, propagates to the soma and is manifesting at low frequencies of stimulation. We show that this aberrant excitability is associated with a deficient adenosine tone, an inhibitory neuromodulator, driven by reduced levels of CD39/73 enzymes, responsible for the extracellular ATP-to-adenosine conversion.

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Heart failure is a major clinical problem, with treatments involving medication, devices, and emerging neuromodulation therapies such as vagus nerve stimulation (VNS). Considering the ongoing interest in using VNS to treat cardiovascular disease, it is important to understand the genetic and molecular changes developing in the heart in response to this form of autonomic neuromodulation. This experimental animal (rat) study investigated the immediate transcriptional response of the ventricular myocardium to selective stimulation of vagal efferent activity using an optogenetic approach.

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During hypoxia, increases in cerebral blood flow maintain brain oxygen delivery. Here, we describe a mechanism of brain oxygen sensing that mediates the dilation of intraparenchymal cerebral blood vessels in response to reductions in oxygen supply. In vitro and in vivo experiments conducted in rodent models show that during hypoxia, cortical astrocytes produce the potent vasodilator nitric oxide (NO) via nitrite reduction in mitochondria.

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Purpose: To describe variation in local anesthesia techniques and complications over a 10-year period for cataract surgery in the United Kingdom.

Setting: Reporting centers to the Royal College of Ophthalmologists (RCOphth) National Ophthalmology Database (NOD).

Design: Retrospective cross-sectional register-based study.

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Objective: To establish the incidence of acute intraoperative suprachoroidal haemorrhage (AISH) during cataract surgery and identify the risk factors for this complication.

Methods: Data from the Royal College of Ophthalmologists' National Ophthalmology Database was analysed. During the 11-year study period, from 01/04/2010 to 31/03/2021, 709 083 operations performed on 498 170 patients from 65 centres were eligible for inclusion.

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Article Synopsis
  • Students participated in an 8-week online research program where they learned to incorporate primary literature into their science projects, targeting 8th to 11th graders.
  • Each week focused on a specific section of a primary research article, guiding students on how to write corresponding sections in their own research papers.
  • At the end of the program, students reported increased self-efficacy and confidence in scientific writing, and the paper offers a framework for integrating primary literature into similar projects.
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Neural stem cell (NSC) transplantation induces recovery in animal models of central nervous system (CNS) diseases. Although the replacement of lost endogenous cells was originally proposed as the primary healing mechanism of NSC grafts, it is now clear that transplanted NSCs operate via multiple mechanisms, including the horizontal exchange of therapeutic cargoes to host cells via extracellular vesicles (EVs). EVs are membrane particles trafficking nucleic acids, proteins, metabolites and metabolic enzymes, lipids, and entire organelles.

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Mechanosensitivity is a well-known feature of astrocytes, however, its underlying mechanisms and functional significance remain unclear. There is evidence that astrocytes are acutely sensitive to decreases in cerebral perfusion pressure and may function as intracranial baroreceptors, tuned to monitor brain blood flow. This study investigated the mechanosensory signaling in brainstem astrocytes, as these cells reside alongside the cardiovascular control circuits and mediate increases in blood pressure and heart rate induced by falls in brain perfusion.

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Spinal cord injury (SCI) is a debilitating neurological condition characterized by different cellular and molecular mechanisms that interplay in exacerbating the progression of the pathology. No fully restorative therapies are yet available, and it is thus becoming recognized that combinatorial approaches aimed at addressing different aspects of SCI will likely results in greater functional outcomes. Here we employed packaging RNA-mediated RNA interference (pRNA-RNAi) nanotherapeutics to downregulate in situ the expression of lipocalin 2 (Lcn2), a known mediator of neuroinflammation and autocrine mediator of reactive astrogliosis, and to create a more amenable niche for the subsequent transplantation of induced neural stem cells (iNSCs).

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In response to injuries to the CNS, astrocytes enter a reactive state known as astrogliosis, which is believed to be deleterious in some contexts. Activated astrocytes overexpress intermediate filaments including glial fibrillary acidic protein (GFAP) and vimentin (Vim), resulting in entangled cells that inhibit neurite growth and functional recovery. Reactive astrocytes also secrete inflammatory molecules such as Lipocalin 2 (Lcn2), which perpetuate reactivity and adversely affect other cells of the CNS.

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Neural stem cell (NSC) transplantation can influence immune responses and suppress inflammation in the CNS. Metabolites, such as succinate, modulate the phenotype and function of immune cells, but whether and how NSCs are also activated by such immunometabolites to control immunoreactivity and inflammatory responses is unclear. Here, we show that transplanted somatic and directly induced NSCs ameliorate chronic CNS inflammation by reducing succinate levels in the cerebrospinal fluid, thereby decreasing mononuclear phagocyte (MP) infiltration and secondary CNS damage.

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Article Synopsis
  • Oligodendrocyte loss can cause issues with thinking and movement, prompting the need for therapies that can either enhance the body's own precursors or use transplanted oligodendrocytes.
  • A new method has been developed to extract and expand oligodendrocyte lineage cells from adult rat meninges, yielding about 10 million cells from just a small tissue sample in about 4 weeks.
  • These meningeal-derived cells not only show characteristics of mature oligodendrocytes but also have potential to remyelinate damaged areas in the spinal cord, making them a promising option for treating demyelinating diseases.
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Objective: To compare the static postural balance between women suffering from chronic low back pain and healthy subjects, by moving the center of pressure.

Methods: The study included 15 women with low back pain (LBP group) and 15 healthy women (healthy group). They were instructed to remain in standing on the force platform for 30 seconds.

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Background: The incidence of venous thromboembolic (VTE) events in children has increased in recent years (J Neurosurg, 101, 2004, 32; J Thromb Haemost, 1, 2003, 1443) yet there is currently no consensus as to what VTE prophylaxis, if any, should be applied to the pediatric population.

Objectives/aims: Our aim was to audit current practice in pediatric VTE prophylaxis across England and Wales and to advocate simple measures for prevention. We illustrate the importance of the condition with a series of cases from the South West Paediatric Burns and Neurosurgical Services based in Bristol.

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