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BACKGROUND: The optimal assessment of systemic and lung decongestion during acute heart failure is not clearly defined. We evaluated whether inferior vena cava (IVC) and pulmonary ultrasound (CAVAL US) guided therapy is superior to standard care in reducing subclinical congestion at discharge in patients with AHF. METHODS: CAVAL US-AHF was an investigator-initiated, single-center, single-blind, randomized controlled trial. A daily quantitative ultrasound protocol using the 8-zone method was used and treatment was adjusted according to an algorithm. The primary endpoint was the presence of more than 5 B-lines and/or an increase in IVC diameter and collapsibility at discharge. And secondary endpoint exploratory outcome was the composite of readmission for HF, unplanned visit for worsening HF or death at 90 days RESULTS: Sixty patients were randomized to CAVAL US (n = 30) or control (n = 30). The primary endpoint was achieved in 4 patients (13.3%) in the CAVAL US group and 20 patients (66.6%) in the control group (P < .001). A significant reduction in HF readmission, unplanned visit for worsening HF or death at 90 days was seen in the CAVAL US group (13.3% vs 36.7%; log rank P = .038). Other endpoints such as NT-proBNP reduction at discharge showed a nonstatistically significant reduction in the CAVAL US group (48% IQR 27-67 vs 37% -3-59; P = .09). Safety outcomes were similar in both groups. CONCLUSION: IVC and lung ultrasound-guided therapy in AHF patients significantly reduced subclinical congestion at discharge. CAVAL US-AHF provides preliminary evidence for the potential use of a simple technique to guide decongestive therapy during hospitalization for AHF, which may reduce the composite outcome at 90 days.
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In natural odor environments, odor travels in plumes. Odor concentration dynamics change in characteristic ways across the width and length of a plume. Thus, spatiotemporal dynamics of plumes have informative features for animals navigating to an odor source. Population activity in the olfactory bulb (OB) has been shown to follow odor concentration across plumes to a moderate degree (Lewis et al., 2021). However, it is unknown whether the ability to follow plume dynamics is driven by individual cells or whether it emerges at the population level. Previous research has explored the responses of individual OB cells to isolated features of plumes, but it is difficult to adequately sample the full feature space of plumes as it is still undetermined which features navigating mice employ during olfactory guided search. Here we released odor from an upwind odor source and simultaneously recorded both odor concentration dynamics and cellular response dynamics in awake, head-fixed mice. We found that longer timescale features of odor concentration dynamics were encoded at both the cellular and population level. At the cellular level, responses were elicited at the beginning of the plume for each trial, signaling plume onset. Plumes with high odor concentration elicited responses at the end of the plume, signaling plume offset. Although cellular level tracking of plume dynamics was observed to be weak, we found that at the population level, OB activity distinguished whiffs and blanks (accurately detected odor presence versus absence) throughout the duration of a plume. Even ~20 OB cells were enough to accurately discern odor presence throughout a plume. Our findings indicate that the full range of odor concentration dynamics and high frequency fluctuations are not encoded by OB spiking activity. Instead, relatively lower-frequency temporal features of plumes, such as plume onset, plume offset, whiffs, and blanks, are represented in the OB.
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INTRODUCTION: Safety and early clinical benefit make sodium-glucose cotransporter-2 inhibitor (SGLT2-i) therapy suitable for in-hospital initiation in patients with heart failure and reduced ejection fraction (HFrEF). Despite randomized controlled trials and guideline recommendations, they are underused, and clinical inertia may play a role. OBJECTIVES PRIMARY: To assess the impact of initiating SGLT-2i at discharge on 90-day prescription rates in patients with HFrEF during hospitalization for acute heart failure (AHF). Secondary: To evaluate the presence of independent factors associated with prescription, and to explore clinical outcomes at 90 days. METHODS: Retrospective analysis of a consecutive prospective single-center cohort. Adult patients hospitalized between January 2021 and September 2022 with a primary diagnosis of AHF and left ventricular ejection fraction (LVEF) <40% were included. The primary outcome was SGLT2-i prescription rate at 90 days, and the exploratory secondary endpoints was the composite of hospitalization or urgent visit for AHF or all-cause mortality at 90 days. RESULTS: 237 patients were included. Mean age was 76±11 years, and mean LVEF was 29±7%. In patients without contraindications, SGLT2 inhibitors (SGLT2-i) were prescribed during hospitalization in 52.3%. At 90 days, the SGLT2-i prescription rate was 94.2% in those with in-hospital initiation and 14.4% in those without. (p<0.001). Independent factor associated with inpatient prescription was lower LVEF, 0.83 (95% CI: 0.77-0.89) for each point. Patients with in-hospital SGLT2-i initiation showed a lower rate of the combined endpoint of all-cause death, HF rehospitalization, or unplanned HF visit at 90 days (44.4% versus 23.9%, p=0.005). CONCLUSIONS: In-hospital initiation of SGLT-2-i was associated with significantly higher prescription rates and lower prevalence in the secondary combined endpoint at 90 days. This study reflects the presence of medical inertia, particularly in patients with higher LVEF, and highlights the hospitalization period as an optimal time to start SGLT2-i.
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Insuficiencia Cardíaca , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Volumen Sistólico , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Prescripciones de Medicamentos/estadística & datos numéricos , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/fisiopatología , Hospitalización/estadística & datos numéricos , Pautas de la Práctica en Medicina/estadística & datos numéricos , Estudios Retrospectivos , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Volumen Sistólico/fisiología , Factores de Tiempo , Función Ventricular Izquierda/fisiología , Función Ventricular Izquierda/efectos de los fármacosRESUMEN
To understand the neural basis of behavior, it is essential to measure spiking dynamics across many interacting brain regions. Although new technologies, such as Neuropixels probes, facilitate multi-regional recordings, significant surgical and procedural hurdles remain for these experiments to achieve their full potential. Here, we describe skull-shaped hemispheric implants enabling large-scale electrophysiology datasets (SHIELD). These 3D-printed skull-replacement implants feature customizable insertion holes, allowing dozens of cortical and subcortical structures to be recorded in a single mouse using repeated multi-probe insertions over many days. We demonstrate the procedure's high success rate, biocompatibility, lack of adverse effects on behavior, and compatibility with imaging and optogenetics. To showcase SHIELD's scientific utility, we use multi-probe recordings to reveal novel insights into how alpha rhythms organize spiking activity across visual and sensorimotor networks. Overall, this method enables powerful, large-scale electrophysiological experiments for the study of distributed neural computation.
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Encéfalo , Cráneo , Animales , Ratones , Encéfalo/fisiología , Cráneo/cirugía , Optogenética/métodos , Fenómenos Electrofisiológicos/fisiología , Impresión Tridimensional , Potenciales de Acción/fisiología , Electrodos Implantados , Ratones Endogámicos C57BL , Masculino , Electrofisiología/métodosRESUMEN
When sensory information is incomplete or ambiguous, the brain relies on prior expectations to infer perceptual objects. Despite the centrality of this process to perception, the neural mechanism of sensory inference is not known. Illusory contours (ICs) are key tools to study sensory inference because they contain edges or objects that are implied only by their spatial context. Using cellular resolution, mesoscale two-photon calcium imaging and multi-Neuropixels recordings in the mouse visual cortex, we identified a sparse subset of neurons in the primary visual cortex (V1) and higher visual areas that respond emergently to ICs. We found that these highly selective 'IC-encoders' mediate the neural representation of IC inference. Strikingly, selective activation of these neurons using two-photon holographic optogenetics was sufficient to recreate IC representation in the rest of the V1 network, in the absence of any visual stimulus. This outlines a model in which primary sensory cortex facilitates sensory inference by selectively strengthening input patterns that match prior expectations through local, recurrent circuitry. Our data thus suggest a clear computational purpose for recurrence in the generation of holistic percepts under sensory ambiguity. More generally, selective reinforcement of top-down predictions by pattern-completing recurrent circuits in lower sensory cortices may constitute a key step in sensory inference.
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Although mice locate resources using turbulent airborne odor plumes, the stochasticity and intermittency of fluctuating plumes create challenges for interpreting odor cues in natural environments. Population activity within the olfactory bulb (OB) is thought to process this complex spatial and temporal information, but how plume dynamics impact odor representation in this early stage of the mouse olfactory system is unknown. Limitations in odor detection technology have made it difficult to measure plume fluctuations while simultaneously recording from the mouse's brain. Thus, previous studies have measured OB activity following controlled odor pulses of varying profiles or frequencies, but this approach only captures a subset of features found within olfactory plumes. Adequately sampling this feature space is difficult given a lack of knowledge regarding which features the brain extracts during exposure to natural olfactory scenes. Here we measured OB responses to naturally fluctuating odor plumes using a miniature, adapted odor sensor combined with wide-field GCaMP6f signaling from the dendrites of mitral and tufted (MT) cells imaged in olfactory glomeruli of head-fixed mice. We precisely tracked plume dynamics and imaged glomerular responses to this fluctuating input, while varying flow conditions across a range of ethologically-relevant values. We found that a consistent portion of MT activity in glomeruli follows odor concentration dynamics, and the strongest responding glomeruli are the best at following fluctuations within odor plumes. Further, the reliability and average response magnitude of glomerular populations of MT cells are affected by the flow condition in which the animal samples the plume, with the fidelity of plume following by MT cells increasing in conditions of higher flow velocity where odor dynamics result in intermittent whiffs of stronger concentration. Thus, the flow environment in which an animal encounters an odor has a large-scale impact on the temporal representation of an odor plume in the OB. Additionally, across flow conditions odor dynamics are a major driver of activity in many glomerular networks. Taken together, these data demonstrate that plume dynamics structure olfactory representations in the first stage of odor processing in the mouse olfactory system.
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Liver X receptors (LXR) are important transcription factors involved in the regulation of carbohydrate and lipid metabolism. Recently, we described LXR receptors expression in the hypothalamus but their function in this brain area remains unknown. Here, we evaluated the function of LXR on the expression of factors produced in the hypothalamus in vitro and in vivo by Western blotting and immunocytochemistry. More precisely we studied the expression of GnRH and GHRH, αMSH and NPY in male Sprague-Dawley rats. The effects of two synthetic LXR agonists, T0901317 and GW3965, were first tested in vitro. Hypothalamic explants were treated with either T0901317 or GW3965 (10µM) for 2, 4, 6 and 8h. As a positive control the cholesterol ABCA1 and glucose GLUT2 transporters were used. No changes were observed in the expression of the factors evaluated in vitro. The effects of the LXR agonists were then tested in vivo. Rats were injected ICV into the third ventricle with either T0901317 or GW3965 (2.5µg/5µL ICV) and after 3.5h or 24h the hypothalami were dissected out and rapidly frozen for analysis. αMSH and GnRH expression was significantly increased after 3.5h of T0901317 treatment. Anterior/posterior hypothalamic ratio increases for αMSH expression and decreases for GnRH expression after 24h of LXR activation. Altogether these results show that LXR activation affects the expression of GnRH and αMSH, suggesting that LXR in the hypothalamus is capable of modulating hypothalamic responses related to appetite, sexual behavior and reproductive functions.
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Hormona Liberadora de Gonadotropina/biosíntesis , Hipotálamo/metabolismo , Receptores X del Hígado/metabolismo , alfa-MSH/biosíntesis , Animales , Expresión Génica , Hormona Liberadora de Gonadotropina/genética , Hidrocarburos Fluorados/farmacología , Hipotálamo/efectos de los fármacos , Receptores X del Hígado/agonistas , Masculino , Ratas , Ratas Sprague-Dawley , Sulfonamidas/farmacología , alfa-MSH/genéticaRESUMEN
Liver X receptors (LXR) are important transcription factors involved in the regulation of carbohydrate and lipid metabolism and are expressed in different brain areas. Recently we described that LXR expression in the hypothalamus is sensitive to serum levels of lipids and carbohydrates. Here, we further characterized the effects of glucose, insulin, cholesterol and cholic acid on the expression of LXRα and LXRß in hypothalamus and hippocampus explants as in vitro models. The LXR activation products, GLUT2 and ABCA1, were also analyzed by Western blot. Glucose had different effects in the hypothalamus compared to the hippocampus. In the hypothalamus, increases in glucose concentrations decreased LXRß expression while in the hippocampus increased both receptor subtypes levels. In contrast, insulin treatment decreased LXRß in the hypothalamus while having no effects on the hippocampus. Cholic acid and cholesterol increased only LXRα expression in the hypothalamus whereas no effects on the hippocampus were detected. The newly expressed LXR receptors may be functional active since the level of the LXR activation product ABCA1 was also increased. Changes in GLUT2 expression was observed only when LXRß levels were increased. Altogether these data show that LXR are sensitive to glucose, insulin and lipids in vitro, as well as in vivo as we previously showed, suggesting an involvement of LXR in central metabolic pathways and control of energy homeostasis.