RESUMEN
Dopamine (DA) is a central monoamine neurotransmitter involved in many physiological and pathological processes. A longstanding yet largely unmet goal is to measure DA changes reliably and specifically with high spatiotemporal precision, particularly in animals executing complex behaviors. Here, we report the development of genetically encoded GPCR-activation-based-DA (GRABDA) sensors that enable these measurements. In response to extracellular DA, GRABDA sensors exhibit large fluorescence increases (ΔF/F0 â¼90%) with subcellular resolution, subsecond kinetics, nanomolar to submicromolar affinities, and excellent molecular specificity. GRABDA sensors can resolve a single-electrical-stimulus-evoked DA release in mouse brain slices and detect endogenous DA release in living flies, fish, and mice. In freely behaving mice, GRABDA sensors readily report optogenetically elicited nigrostriatal DA release and depict dynamic mesoaccumbens DA signaling during Pavlovian conditioning or during sexual behaviors. Thus, GRABDA sensors enable spatiotemporally precise measurements of DA dynamics in a variety of model organisms while exhibiting complex behaviors.
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Dopamina/análisis , Drosophila/metabolismo , Pez Cebra/metabolismo , Animales , Animales Modificados Genéticamente/genética , Animales Modificados Genéticamente/metabolismo , Conducta Animal , Dopamina/metabolismo , Femenino , Proteínas Fluorescentes Verdes/genética , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Fluorescente , Neuronas/citología , Neuronas/metabolismo , Optogenética/métodos , Receptores Acoplados a Proteínas G/genética , Canales Catiónicos TRPV/genética , Proteínas de Pez Cebra/genéticaRESUMEN
Dopamine (DA) plays a critical role in the brain, and the ability to directly measure dopaminergic activity is essential for understanding its physiological functions. We therefore developed red fluorescent G-protein-coupled receptor-activation-based DA (GRABDA) sensors and optimized versions of green fluorescent GRABDA sensors. In response to extracellular DA, both the red and green GRABDA sensors exhibit a large increase in fluorescence, with subcellular resolution, subsecond kinetics and nanomolar-to-submicromolar affinity. Moreover, the GRABDA sensors resolve evoked DA release in mouse brain slices, detect evoked compartmental DA release from a single neuron in live flies and report optogenetically elicited nigrostriatal DA release as well as mesoaccumbens dopaminergic activity during sexual behavior in freely behaving mice. Coexpressing red GRABDA with either green GRABDA or the calcium indicator GCaMP6s allows tracking of dopaminergic signaling and neuronal activity in distinct circuits in vivo.
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Técnicas Biosensibles/métodos , Encéfalo/metabolismo , Dopamina/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Conducta Sexual/fisiología , Animales , Drosophila/genética , Drosophila/metabolismo , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Células HEK293 , Humanos , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Ratones , Neuronas/metabolismo , Ratas , Receptores Dopaminérgicos/genética , Receptores Dopaminérgicos/metabolismo , Receptores Acoplados a Proteínas G/genética , Proteína Fluorescente RojaRESUMEN
Neuromodulation of neural networks, whereby a selected circuit is regulated by a particular modulator, plays a critical role in learning and memory. Among neuromodulators, acetylcholine (ACh) plays a critical role in hippocampus-dependent memory and has been shown to modulate neuronal circuits in the hippocampus. However, it has remained unknown how ACh modulates hippocampal output. Here, using in vitro and in vivo approaches, we show that ACh, by activating oriens lacunosum moleculare (OLM) interneurons and therefore augmenting the negative-feedback regulation to the CA1 pyramidal neurons, suppresses the circuit from the hippocampal area CA1 to the deep-layer entorhinal cortex (EC). We also demonstrate, using mouse behavior studies, that the ablation of OLM interneurons specifically impairs hippocampus-dependent but not hippocampus-independent learning. These data suggest that ACh plays an important role in regulating hippocampal output to the EC by activating OLM interneurons, which is critical for the formation of hippocampus-dependent memory.
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Neuronas Colinérgicas/citología , Corteza Entorrinal/citología , Hipocampo/citología , Interneuronas/citología , Acetilcolina/metabolismo , Animales , Neuronas Colinérgicas/metabolismo , Corteza Entorrinal/metabolismo , Hipocampo/metabolismo , Interneuronas/metabolismo , Masculino , Ratones , Vías NerviosasRESUMEN
Administration of exosomes derived from mesenchymal stromal cells (MSCs) could improve some neurologic conditions by transferring functional biomolecules to recipient cells. Furthermore, exosomes from hypoxic progenitor cells exerted better therapeutic effects in organ injury through specific cargoes. However, there are no related reports about whether exosomes derived from MSCs or hypoxia-preconditioned MSCs (PC-MSCs) could prevent memory deficits in Alzheimer disease (AD). In this study, the exosomes derived from MSCs or PC-MSCs were systemically administered to transgenic APP/PS1 mice. The expression of miR-21 in MSCs was significantly increased after hypoxic treatment. Injection of exosomes from normoxic MSCs could rescue cognition and memory impairment according to results of the Morris water maze test, reduced plaque deposition, and Aß levels in the brain; could decrease the activation of astrocytes and microglia; could down-regulate proinflammatory cytokines (TNF-α and IL-1ß); and could up-regulate anti-inflammatory cytokines (IL-4 and -10) in AD mice, as well as reduce the activation of signal transducer and activator of transcription 3 (STAT3) and NF-κB. Compared to the group administered exosomes from normoxic MSCs, in the group administered exosomes from PC-MSCs, learning and memory capabilities were significantly improved; the plaque deposition and Aß levels were lower, and expression of growth-associated protein 43, synapsin 1, and IL-10 was increased; and the levels of glial fibrillary acidic protein, ionized calcium-binding adaptor molecule 1, TNF-α, IL-1ß, and activation of STAT3 and NF-κB were sharply decreased. More importantly, exosomes from PC-MSCs effectively increased the level of miR-21 in the brain of AD mice. Additionally, replenishment of miR-21 restored the cognitive deficits in APP/PS1 mice and prevented pathologic features. Taken together, these findings suggest that exosomes from PC-MSCs could improve the learning and memory capabilities of APP/PS1 mice, and that the underlying mechanism may lie in the restoration of synaptic dysfunction and regulation of inflammatory responses through regulation of miR-21.-Cui, G.-H., Wu, J., Mou, F.-F., Xie, W.-H., Wang, F.-B., Wang, Q.-L., Fang, J., Xu, Y.-W., Dong, Y.-R., Liu, J.-R., Guo, H.-D. Exosomes derived from hypoxia-preconditioned mesenchymal stromal cells ameliorate cognitive decline by rescuing synaptic dysfunction and regulating inflammatory responses in APP/PS1 mice.
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Enfermedad de Alzheimer/metabolismo , Encéfalo/metabolismo , Disfunción Cognitiva/metabolismo , Exosomas/metabolismo , Precondicionamiento Isquémico , Células Madre Mesenquimatosas/metabolismo , Sinapsis/metabolismo , Enfermedad de Alzheimer/patología , Animales , Encéfalo/patología , Disfunción Cognitiva/patología , Citocinas/metabolismo , Exosomas/patología , Células Madre Mesenquimatosas/patología , Ratones , Ratones Transgénicos , Sinapsis/patologíaRESUMEN
PURPOSE: Identifying previous chronic cerebral hemorrhage (PCH), especially asymptomatic cases in patients with ischemic stroke, is essential for proper antithrombotic management. The study aimed to further clarify the prevalence of PCH and the associated factors in patients with acute ischemic stroke using multi-modal neuroimaging including susceptibility-weighted MR imaging (SWI). METHODS: This was a retrospective cross-sectional study of 382 patients with acute ischemic stroke. All patients underwent 3.0-T MRI for cranial SWI, 1.5-T or 3.0-T conventional cranial MRI, and cranial CT. Patients found with PCH were matched 1:4 with patients without PCH. Clinical manifestation, computed tomography, conventional cranial MRI, and cranial SWI were used to determine PCH. Clinical and neuroimaging findings between the patients with symptomatic vs. asymptomatic PCH were compared. RESULTS: Thirty-six patients (36/382, 9.4%) were determined to have had a PCH. Of these 36 patients, 17 (17/36, 47.2%, or 17/382, 4.5%) had asymptomatic PCH. Multivariable analysis showed that serum total cholesterol (OR = 0.510, 95%CI 0.312-0.832, P = 0.007), cerebral microbleeds (OR = 6.251, 95%CI 2.220-17.601, P = 0.001), and antithrombotic drugs history (OR = 3.213, 95%CI 1.018-10.145, P = 0.047) were independently associated with PCH. Asymptomatic PCH had similar clinical and neuroimaging characteristics with symptomatic PCH. CONCLUSION: PCH is not uncommon in acute ischemic stroke patients. Total serum cholesterol, cerebral microbleeds on SWI, and history of antithrombotic drugs were independently associated with PCH in patients with acute ischemic stroke. Asymptomatic PCH, which is easier to be missed and has similar characteristics with symptomatic PCH, should draw much attention.
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Isquemia Encefálica/diagnóstico por imagen , Hemorragia Cerebral/diagnóstico por imagen , Imagen Multimodal , Neuroimagen/métodos , Accidente Cerebrovascular/diagnóstico por imagen , Enfermedad Crónica , Estudios Transversales , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodosRESUMEN
The basal ganglia are subcortical nuclei that control voluntary actions, and they are affected by a number of debilitating neurological disorders. The prevailing model of basal ganglia function proposes that two orthogonal projection circuits originating from distinct populations of spiny projection neurons (SPNs) in the striatum--the so-called direct and indirect pathways--have opposing effects on movement: activity of direct-pathway SPNs is thought to facilitate movement, whereas activity of indirect-pathway SPNs is presumed to inhibit movement. This model has been difficult to test owing to the lack of methods to selectively measure the activity of direct- and indirect-pathway SPNs in freely moving animals. Here we develop a novel in vivo method to specifically measure direct- and indirect-pathway SPN activity, using Cre-dependent viral expression of the genetically encoded calcium indicator (GECI) GCaMP3 in the dorsal striatum of D1-Cre (direct-pathway-specific) and A2A-Cre (indirect-pathway-specific) mice. Using fibre optics and time-correlated single-photon counting (TCSPC) in mice performing an operant task, we observed transient increases in neural activity in both direct- and indirect-pathway SPNs when animals initiated actions, but not when they were inactive. Concurrent activation of SPNs from both pathways in one hemisphere preceded the initiation of contraversive movements and predicted the occurrence of specific movements within 500 ms. These observations challenge the classical view of basal ganglia function and may have implications for understanding the origin of motor symptoms in basal ganglia disorders.
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Movimiento/fisiología , Neostriado/citología , Neostriado/fisiología , Vías Nerviosas/fisiología , Animales , Señalización del Calcio , Femenino , Tecnología de Fibra Óptica/métodos , Fluorescencia , Integrasas/genética , Integrasas/metabolismo , Mediciones Luminiscentes/métodos , Masculino , Ratones , Modelos Neurológicos , Enfermedad de Parkinson , FotonesRESUMEN
BACKGROUND: Exosomes are lipid-bilayer enclosed nano-sized vesicles that transfer functional cellular proteins, mRNA and miRNAs. Mesenchymal stem cells (MSCs) derived exosomes have been demonstrated to prevent memory deficits in the animal model of Alzheimer's disease (AD). However, the intravenously injected exosomes could be abundantly tracked in other organs except for the targeted regions in the brain. Here, we proposed the use of central nervous system-specific rabies viral glycoprotein (RVG) peptide to target intravenously-infused exosomes derived from MSCs (MSC-Exo) to the brain of transgenic APP/PS1 mice. MSC-Exo were conjugated with RVG through a DOPE-NHS linker. RESULTS: RVG-tagged MSC-Exo exhibited improved targeting to the cortex and hippocampus after being administered intravenously. Compared with the group administered MSC-Exo, in the group administered RVG-conjugated MSC-Exo (MSC-RVG-Exo) plaque deposition and Aß levels were sharply decreased and activation of astrocytes was obviously reduced. The brain targeted exosomes derived from MSCs was better than unmodified exosomes to improve cognitive function in APP/PS1 mice according to Morris water maze test. Additionally, although MSC-Exo injected intravenously reduced the expression of pro-inflammatory mediators TNF-α, IL-ß, and IL-6, but the changes of anti-inflammatory factors IL-10 and IL-13 were not obvious. However, administration of MSC-RVG-Exo significantly reduced the levels of TNF-α, IL-ß, and IL-6 while significantly raised the levels of IL-10, IL-4 and IL-13. CONCLUSIONS: Taken together, our results demonstrated a novel method for increasing delivery of exosomes for treatment of AD. By targeting exosomes to the cortex and hippocampus of AD mouse, there was a significant improvement in learning and memory capabilities with reduced plaque deposition and Aß levels, and normalized levels of inflammatory cytokines.
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INTRODUCTION: Multiple microRNAs (miRNAs) participate in the response to hypoxic/ischemic and ischemia-reperfusion events. However, the expression of these miRNAs in circulation from patients with acute ischemic stroke (AIS) receiving recanalization treatment has not been examined, and whether they are associated with the severity and outcome of stroke is still unknown. MATERIALS AND METHODS: In this prospective cohort study, plasma levels of miR-125b-5p, miR-15a-3p, miR-15a-5p, and miR-206 were measured at 24 hours after thrombolysis with or without endovascular treatment in 94 patients with AIS, as determined by qRT-PCR. Stroke severity was assessed based on National Institutes of Health Stroke Scale (NIHSS) score and infarct lesion. Intracranial haemorrhage (ICH) was recorded. An unfavorable outcome was defined as a modified Rankin Scale score greater than 2 at day 90 after stroke. RESULTS: miR-125b-5p and miR-206 levels were correlated with NIHSS scores (Pâ¯=â¯.014 and Pâ¯=â¯.002) and cerebral infarction volumes (Pâ¯=â¯.025 and Pâ¯=â¯.030). miR-125b-5p levels were significantly higher in patients with an unfavorable outcome than in patients with a favorable outcome (Pâ¯=â¯.002) and showed good diagnostic accuracy in discriminating the presence of an unfavorable outcome (area under the curve .735, 95% confidence interval .623-.829, P < .001). No association was found between different miRNAs and ICH. CONCLUSIONS: In AIS patients after thrombolysis with or without endovascular treatment, miR-125b-5p is a novel prognostic biomarker highly associated with an unfavorable outcome. miR-125b-5p and miR-206 levels are associated with stroke severity.
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Isquemia Encefálica/terapia , MicroARN Circulante/sangre , Procedimientos Endovasculares , MicroARNs/sangre , Accidente Cerebrovascular/terapia , Terapia Trombolítica , Anciano , Anciano de 80 o más Años , Isquemia Encefálica/sangre , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/genética , MicroARN Circulante/genética , Imagen de Difusión por Resonancia Magnética , Evaluación de la Discapacidad , Femenino , Marcadores Genéticos , Humanos , Masculino , MicroARNs/genética , Persona de Mediana Edad , Datos Preliminares , Estudios Prospectivos , Recuperación de la Función , Índice de Severidad de la Enfermedad , Accidente Cerebrovascular/sangre , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/genética , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
PURPOSE: The association between intracranial internal carotid artery (IICA) calcification and lacunes, white matter hyperintensity (WMH), and cerebral microbleeds (CMBs) has been well researched. However, enlarged cerebral perivascular space (PVS) has not yet been reported to correlate with intracranial internal carotid artery calcification. Therefore, the primary aim of this study was to investigate the relationship between IICA calcification and enlarged PVS. METHODS: A total of 189 patients with ischemic stroke in the middle cerebral artery territory who presented within 7 days of ictus from 2012 to 2015 were enrolled respectively. All patients were required to have undergone head computed tomography, magnetic resonance imaging, susceptibility-weighted magnetic resonance imaging, magnetic resonance angiography, or computed tomography angiography. Clinical characteristics were recorded. IICA calcification and enlarged PVS were semi-quantitatively evaluated, and the presence of lacunes, WMH, and CMBs was recorded. RESULTS: Of the 189 patients, 63.5% were male. Mean age of the patients was 68.6 ± 12.2 years. There were 104 patients with IICA calcification. Age, diabetes mellitus, lacunes, and white matter hyperintensity were significantly associated with IICA calcification (P < 0.05). Multivariate logistic regression analysis showed that age, diabetes mellitus, and lacunes were independent predictors of IICA calcification (P < 0.05). A lower risk of IICA calcification was found in patients with a higher enlarged PVS score (P = 0.004). CONCLUSION: Higher enlarged PVS scores were associated with a lesser degree of IICA calcification. There appears to be a relationship between reduced risk of IICA calcification and enlarged PVS.
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Isquemia Encefálica/diagnóstico por imagen , Estenosis Carotídea/diagnóstico por imagen , Neuroimagen/métodos , Calcificación Vascular/diagnóstico por imagen , Anciano , Isquemia Encefálica/patología , Estenosis Carotídea/patología , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Hemorragias Intracraneales/diagnóstico por imagen , Hemorragias Intracraneales/patología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Calcificación Vascular/patología , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patologíaRESUMEN
BACKGROUND: Migraine constitute a disorder characterized by recurrent headaches, and have a high prevalence, a high socio-economic burden and severe effects on quality of life. Our previous fMRI study demonstrated that some brain regions are functional alterations in migraineurs. As the function of the human brain is related to its structure, we further investigated white and gray matter structural alterations in migraineurs. METHODS: In current study, we used surface-based morphometry, voxel-based morphometry and diffusion tensor imaging analyses to detect structural alterations of the white matter and gray matter in 32 migraineurs without aura compared with 32 age- and gender-matched healthy controls. RESULTS: We found that migraineurs without aura exhibited significantly increased gray matter volume in the bilateral cerebellar culmen, increased cortical thickness in the lateral occipital-temporal cortex, decreased cortical thickness in the right insula, increased gyrification index in left postcentral gyrus, superior parietal lobule and right lateral occipital cortex, and decreased gyrification index in the left rostral middle frontal gyrus compared with controls. No significant change in white matter microstructure was found in DTI analyses. CONCLUSION: The significantly altered gray matter brain regions were known to be associated with sensory discrimination of pain, multi-sensory integration and nociceptive information processing and were consistent with our previous fMRI study, and may be involved in the pathological mechanism of migraine without aura.
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Imagen de Difusión Tensora , Sustancia Gris/diagnóstico por imagen , Migraña sin Aura/diagnóstico por imagen , Sustancia Blanca/diagnóstico por imagen , Adulto , Encéfalo/diagnóstico por imagen , Imagen de Difusión Tensora/métodos , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Migraña sin Aura/psicología , Calidad de Vida/psicologíaRESUMEN
OBJECTIVE: This study aimed to analyze the features of resting-state functional magnetic resonance imaging (rs-fMRI) and clinical relevance in patients with benign paroxysmal positional vertigo (BPPV) that have undergone repositioning maneuvers. METHODS: A total of 38 patients with BPPV who have received repositioning maneuvers and 38 matched healthy controls (HCs) were enrolled in the present study from March 2018 to August 2021. Imaging analysis software was employed for functional image preprocessing and indicator calculation, mainly including the amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), percent amplitude of fluctuation (PerAF), and seed-based functional connectivity (FC). Statistical analysis of the various functional indicators in patients with BPPV and HCs was also conducted, and correlation analysis with clinical data was performed. RESULTS: Patients with BPPV displayed decrease in ALFF, fALFF, and PerAF values, mainly in the bilateral occipital lobes in comparison with HCs. Additionally, their ALFF and fALFF values in the proximal vermis region of the cerebellum increased relative to HCs. The PerAF values in the bilateral paracentral lobules, the right supplementary motor area (SMA), and the left precuneus decreased in patients with BPPV and were negatively correlated with dizziness visual analog scale (VAS) scores 1 week after repositioning (W1). In addition, in the left fusiform gyrus and lingual gyrus, the PerAF values show a negative correlation with dizziness handicap inventory (DHI) scores at initial visit (W0). Seed-based FC analysis using the seeds from differential clusters of fALFF, ALFF, and PerAF showed reductions between the left precuneus and bilateral occipital lobe, the left precuneus and left paracentral lobule, and within the occipital lobes among patients with BPPV. CONCLUSION: The spontaneous activity of certain brain regions in the bilateral occipital and frontoparietal lobes of patients with BPPV was reduced, whereas the activity in the cerebellar vermis was increased. Additionally, there were reductions in FC between the precuneus and occipital cortex or paracentral lobule, as well as within the occipital cortex. The functional alterations in these brain regions may be associated with the inhibitory interaction and functional integration of visual, vestibular, and sensorimotor systems. The functional alterations observed in the visual cortex and precuneus may represent adaptive responses associated with residual dizziness.
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Vértigo Posicional Paroxístico Benigno , Imagen por Resonancia Magnética , Humanos , Masculino , Femenino , Vértigo Posicional Paroxístico Benigno/fisiopatología , Vértigo Posicional Paroxístico Benigno/diagnóstico por imagen , Persona de Mediana Edad , Adulto , Encéfalo/fisiopatología , Encéfalo/diagnóstico por imagen , Posicionamiento del Paciente/métodos , AncianoRESUMEN
Extracellular vesicles (EVs) derived from adipose-derived stem cells (ADSC-EVs) hold great promise for ischemic stroke treatment, but their therapeutic efficacy is greatly limited due to insufficient targeting ability. Previous reports focused on single ischemic targeting or blood-brain barrier (BBB) penetration, precise delivery to the brain parenchyma has not been fully considered. This study leveraged the targeting ability of RGD peptide and the cell penetrating ability of Angiopep-2 peptide to deliver ADSC-EVs precisely to the impaired brain parenchyma. We found that dual-modified EVs (RA-EVs) significantly enhanced the transcellular permeability across BBB in vitro, and not only targeted ischemic blood vessels but also achieved rapid accumulation in the ischemic lesion area after intravenous administration in vivo. RA-EVs further decreased the infarct volume, apoptosis, BBB disruption, and neurobehavioral deficits. RNA sequencing revealed the molecular regulation mechanism after administration. These findings demonstrate that dual-modification optimizes brain parenchymal targeting and highlights the significance of recruitment and penetration as a previously unidentified strategy for harnessing EVs for therapeutic delivery in ischemic stroke.
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Vesículas Extracelulares , Accidente Cerebrovascular Isquémico , Humanos , Barrera Hematoencefálica , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Encéfalo , Isquemia , Vesículas Extracelulares/fisiologíaRESUMEN
Norepinephrine (NE) is an essential biogenic monoamine neurotransmitter. The first-generation NE sensor makes in vivo, real-time, cell-type-specific and region-specific NE detection possible, but its low NE sensitivity limits its utility. Here, we developed the second-generation GPCR-activation-based NE sensors (GRABNE2m and GRABNE2h) with a superior response and high sensitivity and selectivity to NE both in vitro and in vivo. Notably, these sensors can detect NE release triggered by either optogenetic or behavioral stimuli in freely moving mice, producing robust signals in the locus coeruleus and hypothalamus. With the development of a novel transgenic mouse line, we recorded both NE release and calcium dynamics with dual-color fiber photometry throughout the sleep-wake cycle; moreover, dual-color mesoscopic imaging revealed cell-type-specific spatiotemporal dynamics of NE and calcium during sensory processing and locomotion. Thus, these new GRABNE sensors are valuable tools for monitoring the precise spatiotemporal release of NE in vivo, providing new insights into the physiological and pathophysiological roles of NE.
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Locus Coeruleus , Ratones Transgénicos , Norepinefrina , Optogenética , Animales , Norepinefrina/metabolismo , Ratones , Optogenética/métodos , Locus Coeruleus/metabolismo , Calcio/metabolismo , Vigilia/fisiología , Humanos , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Hipotálamo/metabolismo , Sueño/fisiología , Masculino , Ratones Endogámicos C57BL , Técnicas Biosensibles/métodos , Células HEK293 , Fotometría/métodosRESUMEN
Across mammalian species, new mothers undergo considerable behavioral changes to nurture their offspring and meet the caloric demands of milk production1-5. While many neural circuits underlying feeding and parenting behaviors are well characterized6-9, it is unclear how these different circuits interact and adapt during lactation. Here, we characterized the transcriptomic changes in the arcuate nucleus (ARC) and the medial preoptic area (MPOA) of the mouse hypothalamus in response to lactation and hunger. Furthermore, we showed that heightened appetite in lactating mice was accompanied by increased activity of hunger-promoting agouti-related peptide (AgRP) neurons in the ARC. To assess the strength of hunger versus maternal drives, we designed a conflict assay where female mice chose between a food source or a chamber containing pups and nesting material. Although food-deprived lactating mothers prioritized parenting over feeding, hunger reduced the duration and disrupted the sequences of parenting behaviors in both lactating and virgin females. We discovered that ARCAgRP neurons directly inhibit bombesin receptor subtype-3 (BRS3) neurons in the MPOA, a population that governs both parenting and satiety. Selective activation of this ARCAgRP to MPOABRS3 circuit shifted behaviors from parenting to food-seeking. Thus, hypothalamic networks are modulated by physiological states and work antagonistically during the prioritization of competing motivated behaviors.
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We recently reported that the "Dopamine Neuron Challenge Test" (DNC Test), a diagnostic method that measures the levels of dopamine metabolites in cerebrospinal fluid (CSF) and plasma samples after pharmacologically inducing a transient dopamine release, can detect early-stage Parkinson's disease (PD) with high sensitivity and selectivity in mouse models. The use of haloperidol in the original DNC test to challenge dopamine neurons was less than ideal, as it may cause extrapyramidal motor symptoms. Here we report an improved DNC Test, in which the original challenging agents, haloperidol and methylphenidate, are replaced by a single challenging agent, a dopamine autoreceptor preferring antagonist AJ76 or UH232. We show that the improved DNC Test can achieve the same level of sensitivity and selectivity in detecting early PD in a mouse model without causing motor side effects. These findings significantly improve the practicality of using the DNC Test as a screening or diagnostic test for detecting early-stage PD in the high-risk population in humans.
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Dopamina , Enfermedad de Parkinson , Animales , Ratones , Humanos , Dopamina/metabolismo , Enfermedad de Parkinson/diagnóstico , Enfermedad de Parkinson/tratamiento farmacológico , Haloperidol/farmacología , Haloperidol/uso terapéutico , Ácido Homovanílico/metabolismo , Antagonistas de Dopamina/farmacología , Ácido 3,4-Dihidroxifenilacético/metabolismoRESUMEN
Alzheimer's disease (AD) is a common age-related neurodegenerative disease in the central nervous system and is the primary cause of dementia. It is clinically characterized by the memory impairment, aphasia, apraxia, agnosia, visuospatial and executive dysfunction, behavioral changes, and so on. Incidence of this disease was bound up with age, genetic factors, cardiovascular and cerebrovascular dysfunction, and other basic diseases, but the exact etiology has not been clarified. MicroRNAs (miRNAs) are small endogenous non-coding RNAs that were involved in the regulation of post-transcriptional gene expression. miRNAs have been extensively studied as noninvasive potential biomarkers for disease due to their relative stability in bodily fluids. In addition, they play a significant role in the physiological and pathological processes of various neurological disorders, including stroke, AD, and Parkinson's disease. MiR-155, as an important pro-inflammatory mediator of neuroinflammation, was reported to participate in the progression of ß-amyloid peptide and tau via regulating immunity and inflammation. In this review, we put emphasis on the effects of miR-155 on AD and explore the underlying biological mechanisms which could provide a novel approach for diagnosis and treatment of AD.
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Enfermedad de Alzheimer , MicroARNs , Enfermedades Neurodegenerativas , Humanos , Enfermedad de Alzheimer/patología , MicroARNs/genética , Péptidos beta-Amiloides/metabolismo , Factores de RiesgoRESUMEN
Poor vascularization and insufficient oxygen supply are detrimental to the survival of residual cardiomyocytes or transplanted stem cells after myocardial infarction. To prolong and slow the release of angiogenic factors, which stimulate both angiogenesis and vasculogenesis, we constructed a novel self-assembling peptide by attaching the heparin-binding domain sequence LRKKLGKA to the self-assembling peptide RADA16. This designer self-assembling peptide self-assembled into nanofiber scaffolds under physiological conditions, as observed by atomic force microscopy. The injection of designer self-assembling peptides can efficiently provide the sustained delivery of VEGF for at least 1 month. At 4 weeks after transplantation, cardiac function was improved, and scar size and collagen deposition were markedly reduced in the group receiving VEGF with the LRKKLGKA scaffolds compared with groups receiving VEGF alone, LRKKLGKA scaffolds alone or VEGF with RADA16 scaffolds. The microvessel density in the VEGF with LRKKLGKA group was higher than that in the VEGF with RADA16 group. TUNEL and cleaved caspase-3 expression assays showed that the transplantation of VEGF with LRKKLGKA enhanced cell survival in the infarcted heart. These results present the tailor-made peptide scaffolds as a new generation of sustained-release biomimetic biomaterials and suggest that the use of angiogenic factors along with designer self-assembling peptides can lead to myocardial protection, sufficient angiogenesis, and improvement in cardiac function.
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Inductores de la Angiogénesis/administración & dosificación , Materiales Biomiméticos/administración & dosificación , Corazón/efectos de los fármacos , Contracción Miocárdica/efectos de los fármacos , Infarto del Miocardio/fisiopatología , Factor A de Crecimiento Endotelial Vascular/administración & dosificación , Disfunción Ventricular Izquierda/fisiopatología , Secuencia de Aminoácidos , Inductores de la Angiogénesis/química , Animales , Materiales Biomiméticos/química , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/química , Diseño de Fármacos , Femenino , Fibrosis , Heparina/química , Microscopía de Fuerza Atómica , Infarto del Miocardio/patología , Nanofibras/administración & dosificación , Nanofibras/química , Estructura Terciaria de Proteína , Ratas , Ratas Sprague-Dawley , Factor A de Crecimiento Endotelial Vascular/química , Disfunción Ventricular Izquierda/patologíaRESUMEN
Taohong Siwu decoction (THSWD) is one of the classic prescriptions for promoting blood circulation and removing blood stasis. With the continuous in-depth excavation in basic and clinical research, it has been found that THSWD has made greater progress in the prevention and treatment of cardiovascular diseases. Mechanisms of the current studies have shown that it could prevent and treat the myocardial injury by inhibiting inflammatory reaction, antioxidant stress, inhibiting platelet aggregation, prolonging clotting time, anti-fibrosis, reducing blood lipids, anti-atherosclerosis, improving hemorheology and vascular pathological changes, regulating related signal pathways and other mechanisms to prevent and treat the myocardial injury, so as to protect cardiomyocytes and improve cardiac function. Many clinical studies have shown that THSWD is effective in the prevention and treatment of cardiovascular diseases related to myocardial injuries, such as coronary heart disease angina pectoris (CHD-AP), and myocardial infarction. In clinical practice, it is often used by adding and subtracting prescriptions, the combination of compound prescriptions and combinations of chemicals and so on. However, there are some limitations and uncertainties in both basic and clinical research of prescriptions. According to the current research, although the molecular biological mechanism of various active ingredients needs to be further clarified, and the composition and dose of the drug have not been standardized and quantified, this study still has exploration for scientific research and clinical practice. Therefore, this review mainly discusses the basic mechanisms and clinical applications of THSWD in the prevention and treatment of the myocardial injury caused by CHD-AP and myocardial infarction. The authors hope to provide valuable ideas and references for researchers and clinicians.
RESUMEN
This article describes how to assemble and operate a spectrometer-based fiber photometry system for in vivo simultaneous measurements of multiple fluorescent biosensors in freely moving mice. The first section of the article describes the step-by-step procedure to assemble a basic single-spectrometer fiber photometry system and how to expand it into a dual-spectrometer system that allows for simultaneous recordings from two sites. The second part describes the steps for a typical fiber probe implantation surgery. The last section describes how to acquire and analyze the time-lapsed spectral data. This article is intended for teaching labs how to build their own fiber photometry systems (with a video tutorial) from commercially available parts and perform in vivo recordings in behaving mice. © Published 2022. This article is a U.S. Government work and is in the public domain in the USA. Basic Protocol 1: Assembling a dual-laser, single-spectrometer fiber photometry system Support Protocol: Dual-spectrometer fiber photometry assembly Basic Protocol 2: Optical fiber probe implantation Basic Protocol 3: Data acquisition and analysis.
Asunto(s)
Fibras Ópticas , Fotometría , Animales , Ratones , Fotometría/métodosRESUMEN
Coupling of hemodynamic responses to neuronal activity is the foundation of several functional neuroimaging techniques. Here, we provide three fiber-photometry approaches to simultaneously measure neuronal and vascular signals in the rodent brain using a spectrometer-based system. Two out of these three approaches allow the removal of hemoglobin (Hb)-absorption artifacts and restore the underlying neuronal activity. This technique is applicable to different fluorescent sensors and provides a more accurate measurement of hemodynamic response function in any location of the rodent brain. For complete details on the use and execution of this protocol, please refer to Zhang et al. (2022).