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1.
Sci Data ; 11(1): 353, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589407

RESUMO

Diffusion-weighted MRI (dMRI) is a widely used neuroimaging modality that permits the in vivo exploration of white matter connections in the human brain. Normative structural connectomics - the application of large-scale, group-derived dMRI datasets to out-of-sample cohorts - have increasingly been leveraged to study the network correlates of focal brain interventions, insults, and other regions-of-interest (ROIs). Here, we provide a normative, whole-brain connectome in MNI space that enables researchers to interrogate fiber streamlines that are likely perturbed by given ROIs, even in the absence of subject-specific dMRI data. Assembled from multi-shell dMRI data of 985 healthy Human Connectome Project subjects using generalized Q-sampling imaging and multispectral normalization techniques, this connectome comprises ~12 million unique streamlines, the largest to date. It has already been utilized in at least 18 peer-reviewed publications, most frequently in the context of neuromodulatory interventions like deep brain stimulation and focused ultrasound. Now publicly available, this connectome will constitute a useful tool for understanding the wider impact of focal brain perturbations on white matter architecture going forward.


Assuntos
Conectoma , Substância Branca , Humanos , Encéfalo/diagnóstico por imagem , Conectoma/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Neuroimagem , Substância Branca/diagnóstico por imagem
2.
Cell Death Dis ; 15(4): 262, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615026

RESUMO

Gliomas are among the most fatal tumors, and the available therapeutic options are very limited. Additionally, the blood-brain barrier (BBB) prevents most drugs from entering the brain. We designed and produced a ferritin-based stimuli-sensitive nanocarrier with high biocompatibility and water solubility. It can incorporate high amounts of the potent topoisomerase 1 inhibitor Genz-644282. Here, we show that this nanocarrier, named The-0504, can cross the BBB and specifically deliver the payload to gliomas that express high amounts of the ferritin/transferrin receptor TfR1 (CD71). Intranasal or intravenous administration of The-0504 both reduce tumor growth and improve the survival rate of glioma-bearing mice. However, nose-to-brain administration is a simpler and less invasive route that may spare most of the healthy tissues compared to intravenous injections. For this reason, the data reported here could pave the way towards a new, safe, and direct ferritin-based drug delivery method for brain diseases, especially brain tumors.


Assuntos
Ferritinas , Glioma , Animais , Camundongos , Taxa de Sobrevida , Glioma/tratamento farmacológico , Encéfalo , Barreira Hematoencefálica
3.
Sci Rep ; 14(1): 8593, 2024 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615051

RESUMO

Previous studies have indicated that brain functional plasticity and reorganization in patients with degenerative cervical myelopathy (DCM). However, the effects of cervical cord compression on the functional integration and separation between and/or within modules remain unclear. This study aimed to address these questions using graph theory. Functional MRI was conducted on 46 DCM patients and 35 healthy controls (HCs). The intra- and inter-modular connectivity properties of the whole-brain functional network and nodal topological properties were then calculated using theoretical graph analysis. The difference in categorical variables between groups was compared using a chi-squared test, while that between continuous variables was evaluated using a two-sample t-test. Correlation analysis was conducted between modular connectivity properties and clinical parameters. Modules interaction analyses showed that the DCM group had significantly greater inter-module connections than the HCs group (DMN-FPN: t = 2.38, p = 0.02); inversely, the DCM group had significantly lower intra-module connections than the HCs group (SMN: t = - 2.13, p = 0.036). Compared to HCs, DCM patients exhibited higher nodal topological properties in the default-mode network and frontal-parietal network. In contrast, DCM patients exhibited lower nodal topological properties in the sensorimotor network. The Japanese Orthopedic Association (JOA) score was positively correlated with inter-module connections (r = 0.330, FDR p = 0.029) but not correlated with intra-module connections. This study reported alterations in modular connections and nodal centralities in DCM patients. Decreased nodal topological properties and intra-modular connection in the sensory-motor regions may indicate sensory-motor dysfunction. Additionally, increased nodal topological properties and inter-modular connection in the default mode network and frontal-parietal network may serve as a compensatory mechanism for sensory-motor dysfunction in DCM patients. This could provide an implicative neural basis to better understand alterations in brain networks and the patterns of changes in brain plasticity in DCM patients.


Assuntos
Pescoço , Doenças da Medula Espinal , Humanos , Encéfalo/diagnóstico por imagem , Doenças da Medula Espinal/diagnóstico por imagem , Interpretação Estatística de Dados , Plasticidade Neuronal , Fator de Crescimento Transformador beta
4.
Sci Rep ; 14(1): 8605, 2024 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615065

RESUMO

Adolescence is characterized by increased impulsive and risk-taking behaviors. To better understand the neural networks that subserves impulsivity in adolescents, we used a reward-guided behavioral model that quantifies age differences in impulsive actions in adult and adolescent rats of both sexes. Using chemogenetics, we identified orbitofrontal cortex (OFC) projections to the dorsomedial striatum (DMS) as a critical pathway for age-related execution of impulsive actions. Simultaneous recording of single units and local field potentials in the OFC and DMS during task performance revealed an overall muted response in adolescents during impulsive actions as well as age-specific differences in theta power and OFC-DMS functional connectivity. Collectively, these data reveal that the OFC-DMS pathway is critical for age-differences in reward-guided impulsive actions and provide a network mechanism to enhance our understanding of how adolescent and adult brains coordinate behavioral inhibition.


Assuntos
Corpo Estriado , Neostriado , Feminino , Masculino , Animais , Ratos , Comportamento Impulsivo , Encéfalo , Procedimentos Clínicos
5.
Cell Mol Life Sci ; 81(1): 181, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615095

RESUMO

In vertebrates, oligodendrocytes (OLs) are glial cells of the central nervous system (CNS) responsible for the formation of the myelin sheath that surrounds the axons of neurons. The myelin sheath plays a crucial role in the transmission of neuronal information by promoting the rapid saltatory conduction of action potentials and providing neurons with structural and metabolic support. Saltatory conduction, first described in the peripheral nervous system (PNS), is now generally recognized as a universal evolutionary innovation to respond quickly to the environment: myelin helps us think and act fast. Nevertheless, the role of myelin in the central nervous system, especially in the brain, may not be primarily focused on accelerating conduction speed but rather on ensuring precision. Its principal function could be to coordinate various neuronal networks, promoting their synchronization through oscillations (or rhythms) relevant for specific information processing tasks. Interestingly, myelin has been directly involved in different types of cognitive processes relying on brain oscillations, and myelin plasticity is currently considered to be part of the fundamental mechanisms for memory formation and maintenance. However, despite ample evidence showing the involvement of myelin in cognition and neurodevelopmental disorders characterized by cognitive impairments, the link between myelin, brain oscillations, cognition and disease is not yet fully understood. In this review, we aim to highlight what is known and what remains to be explored to understand the role of myelin in high order brain processes.


Assuntos
Bainha de Mielina , Transtornos do Neurodesenvolvimento , Animais , Cognição , Sistema Nervoso Central , Encéfalo
6.
Commun Biol ; 7(1): 457, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615103

RESUMO

Visceral hypersensitivity, a common clinical manifestation of irritable bowel syndrome, may contribute to the development of chronic visceral pain, which is a major challenge for both patients and health providers. Neural circuits in the brain encode, store, and transfer pain information across brain regions. In this review, we focus on the anterior cingulate cortex and paraventricular nucleus of the hypothalamus to highlight the progress in identifying the neural circuits involved in visceral pain. We also discuss several neural circuit mechanisms and emphasize the importance of cross-species, multiangle approaches and the identification of specific neurons in determining the neural circuits that control visceral pain.


Assuntos
Hipersensibilidade , Síndrome do Intestino Irritável , Dor Visceral , Humanos , Encéfalo , Neurônios
7.
CNS Neurosci Ther ; 30(4): e14710, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38615363

RESUMO

AIMS: The present study aimed to explore the effect of cortico-cortical paired-associative stimulation (ccPAS) in modulating hyperdirect pathway and its influence on balance performance. METHODS: Forty healthy participants were randomly allocated to the active ccPAS group (n = 20) or the sham ccPAS group (n = 20). The primary motor cortex and subthalamic nucleus were stimulated sequentially with ccPAS. Unlike the active ccPAS group, one wing of coil was tilted to form a 90° angle with scalp of stimulation locations for the sham ccPAS group. Magnetic resonance imaging, functional reach test (FRT), timed up and go (TUG) test, and limit of stability (LOS) test were performed, and correlation between them was also analyzed. RESULTS: Three participants in the sham ccPAS group were excluded because of poor quality of NIfTI images. The active group had strengthened hyperdirect pathway, increased functional connectivity (FC) between orbital part of frontal cortex and bilateral precuneus, and decreased FC among basal ganglia (all p < 0.05). Regional network properties of triangular and orbital parts of IFG, middle cingulate cortex, and hippocampus increased. The active group performed better in FRT and LOS (all p < 0.05). FRT positively correlated with FC of the hyperdirect pathway (r = 0.439, p = 0.007) and FCs between orbital part of frontal cortex and bilateral precuneus (all p < 0.05). CONCLUSION: The ccPAS enhanced balance performance by promotion-like plasticity mechanisms through the hyperdirect pathway.


Assuntos
Encéfalo , Núcleo Subtalâmico , Humanos , Encéfalo/diagnóstico por imagem , Couro Cabeludo , Gânglios da Base , Lobo Frontal
8.
CNS Neurosci Ther ; 30(4): e14712, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38615364

RESUMO

BACKGROUND: The specific non-motor symptoms associated with α-synucleinopathies, including orthostatic hypotension (OH), cognitive impairment, and emotional abnormalities, have been a subject of ongoing controversy over the mechanisms underlying the development of a vicious cycle among them. The distinct structural alterations in white matter (WM) in patients with α-synucleinopathies experiencing OH, alongside their association with other non-motor symptoms, remain unexplored. This study employs axial diffusivity and density imaging (NODDI) to investigate WM damage specific to α-synucleinopathies with concurrent OH, delivering fresh evidence to supplement our understanding of the pathogenic mechanisms and pathological rationales behind the occurrence of a spectrum of non-motor functional impairments in α-synucleinopathies. METHODS: This study recruited 49 individuals diagnosed with α-synucleinopathies, stratified into an α-OH group (n = 24) and an α-NOH group (without OH, n = 25). Additionally, 17 healthy controls were included for supine and standing blood pressure data collection, as well as neuropsychological assessments. Magnetic resonance imaging (MRI) was utilized for the calculation of NODDI parameters, and tract-based spatial statistics (TBSS) were employed to explore differential clusters. The fibers covered by these clusters were defined as regions of interest (ROI) for the extraction of NODDI parameter values and the analysis of their correlation with neuropsychological scores. RESULTS: The TBSS analysis unveiled specific cerebral regions exhibiting disparities within the α-OH group as compared to both the α-NOH group and the healthy controls. These differences were evident in clusters that indicated a decrease in the acquisition of the neurite density index (NDI), a reduction in the orientation dispersion index (ODI), and an increase in the isotropic volume fraction (FISO) (p < 0.05). The extracted values from these ROIs demonstrated significant correlations with clinically assessed differences in supine and standing blood pressure, overall cognitive scores, and anxiety-depression ratings (p < 0.05). CONCLUSION: Patients with α-synucleinopathies experiencing OH exhibit distinctive patterns of microstructural damage in the WM as revealed by the NODDI model, and there is a correlation with the onset and progression of non-motor functional impairments.


Assuntos
Hipotensão Ortostática , Sinucleinopatias , Substância Branca , Humanos , Substância Branca/diagnóstico por imagem , Hipotensão Ortostática/diagnóstico por imagem , Encéfalo , Depressão , Anticorpos
9.
J Comp Neurol ; 532(4): e25614, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38616537

RESUMO

Comprehensive understanding of interconnected networks within the brain requires access to high resolution information within large field of views and over time. Currently, methods that enable mapping structural changes of the entire brain in vivo are extremely limited. Third harmonic generation (THG) can resolve myelinated structures, blood vessels, and cell bodies throughout the brain without the need for any exogenous labeling. Together with deep penetration of long wavelengths, this enables in vivo brain-mapping of large fractions of the brain in small animals and over time. Here, we demonstrate that THG microscopy allows non-invasive label-free mapping of the entire brain of an adult vertebrate, Danionella dracula, which is a miniature species of cyprinid fish. We show this capability in multiple brain regions and in particular the identification of major commissural fiber bundles in the midbrain and the hindbrain. These features provide readily discernable landmarks for navigation and identification of regional-specific neuronal groups and even single neurons during in vivo experiments. We further show how this label-free technique can easily be coupled with fluorescence microscopy and used as a comparative tool for studies of other species with similar body features to Danionella, such as zebrafish (Danio rerio) and tetras (Trochilocharax ornatus). This new evidence, building on previous studies, demonstrates how small size and relative transparency, combined with the unique capabilities of THG microscopy, can enable label-free access to the entire adult vertebrate brain.


Assuntos
Microscopia de Geração do Segundo Harmônico , Animais , Peixe-Zebra , Encéfalo , Mapeamento Encefálico , Mesencéfalo
10.
J Biochem ; 175(4): 377-381, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38616641

RESUMO

Understanding the mechanisms of drug action in the brain, from the genetic to the neural circuit level, is crucial for the development of new agents that act upon the central nervous system. Determining the brain regions and neurons affected by a drug is essential for revealing its mechanism of action in the brain. c-Fos, a marker of neuronal activation, has been widely used to detect neurons activated by stimuli with high spatial resolution. In this review, the use of c-Fos for the visualization and manipulation of activated neurons is introduced. I also explain that a higher temporal resolution can be achieved by changing the staining method for visualization of c-Fos. Moreover, a new method that allows labeling and manipulating commonly activated neurons using two different stimuli is proposed.


Assuntos
Encéfalo , Neurônios , Coloração e Rotulagem
11.
Isr Med Assoc J ; 26(4): 236-239, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38616669

RESUMO

BACKGROUND: The cavum septi pellucidi (CSP) is a brain-enclosed cavity located on the midline between the two leaflets of the septum pellucidum that separates the lateral ventricles. This structure develops in the fetus from week 18 and can be seen up to week 37 in almost all cases and then begins to disappear. OBJECTIVES: To measure and determine the normative values of the CSP volume in fetuses between 20 to 40 weeks of gestation. METHODS: The study comprised 161 consecutive pregnant women between 20 to 40 weeks of gestation with single viable fetuses. All patients had normal, disease-free pregnancies. Transvaginal or transabdominal ultrasound was used according to the fetal presentation. The fetal head was assessed in mid-sagittal sections. Once the CSP was visualized, its volume was measured using three-dimensional ultrasound with Virtual Organ Computer-aided Analysis software. The width of the CSP was also measured at the biparietal diameter (BPD) plane. RESULTS: Of the 161 fetuses, the CSP volume was measured in 158. In three patients the CSP was not identified. The CSP volume correlated poorly with gestational age (r=0.229) and with the BPD (r=0.295). The mean CSP volume was 0.508 ± 0.372 ml (range: 0.03-1.78 ml). The simple measurement of the CSP width correlated better with gestational age (r=0.535) and the BPD (r=0.484). CONCLUSIONS: The CSP volume had a poor correlation with gestational age; however, the volume did not exceed 2 ml regardless of gestational age. This information can be used to assess pathologies involving the CSP.


Assuntos
Feto , Septo Pelúcido , Humanos , Feminino , Gravidez , Septo Pelúcido/diagnóstico por imagem , Idade Gestacional , Encéfalo
12.
Front Endocrinol (Lausanne) ; 15: 1338980, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38616820

RESUMO

Introduction: Neonatal and early-life hypoglycaemia, is a frequent finding but is often non-specific and asymptomatic, making detection and diagnosis challenging. Hypoglycaemia-induced cerebral injury can be identified by magnetic resonance imaging (MRI) changes in cerebral white matter, occipital lobes, and posterior parietotemporal regions. It is unknown if children may have hypoglycaemic brain injury secondary to unrecognised hypoglycaemia in early life. We have examined retrospective radiological findings of likely brain injury by neuroimaging to investigate the existence of previous missed hypoglycaemic events. Methods: Retrospective MRI data in children in a single tertiary centre, over a ten-year period was reviewed to identify potential cases of unrecognised early-life hypoglycaemia. A detailed search from an electronic radiology repository involved the term "hypoglycaemia'' from text-based reports. The initial report was used for those who required serial scanning. Images specific to relevant reports were further reviewed by a designated paediatric neuroradiologist to confirm likely hypoglycaemia induced brain injury. Medical records of those children were subsequently reviewed to assess if the hypoglycaemia had been diagnosed prior to imaging. Results: A total of 107 MR imaging reports were identified for review, and 52 (48.5%) showed typical features strongly suggestive of hypoglycaemic brain injury. Medical note review confirmed no documented clinical information of hypoglycaemia prior to imaging in 22 (42%) patients, raising the likelihood of missed hypoglycaemic events resulting in brain injury. Conclusions: We have identified the existence of unrecognised childhood hypoglycaemia through neuroimaging review. This study highlights the need for heightened awareness of early life hypoglycaemia to prevent adverse neurological outcomes later in childhood.


Assuntos
Lesões Encefálicas , Hipoglicemia , Recém-Nascido , Humanos , Criança , Estudos Retrospectivos , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética , Hipoglicemia/diagnóstico por imagem , Hipoglicemiantes
13.
Artigo em Inglês | MEDLINE | ID: mdl-38617832

RESUMO

Clinical vignette: We present the case of a patient who developed intra-operative pneumocephalus during left globus pallidus internus deep brain stimulation (DBS) placement for Parkinson's disease (PD). Microelectrode recording (MER) revealed that we were anterior and lateral to the intended target. Clinical dilemma: Clinically, we suspected brain shift from pneumocephalus. Removal of the guide-tube for readjustment of the brain target would have resulted in the introduction of movement resulting from brain shift and from displacement from the planned trajectory. Clinical solution: We elected to leave the guide-tube cannula in place and to pass the final DBS lead into a channel that was located posterior-medially from the center microelectrode pass. Gap in knowledge: Surgical techniques which can be employed to minimize brain shift in the operating room setting are critical for reduction in variation of the final DBS lead placement. Pneumocephalus after dural opening is one potential cause of brain shift. The recognition that the removal of a guide-tube cannula could worsen brain shift creates an opportunity for an intraoperative team to maintain the advantage of the 'fork' in the brain provided by the initial procedure's requirement of guide-tube placement.


Assuntos
Estimulação Encefálica Profunda , Pneumocefalia , Humanos , Estimulação Encefálica Profunda/efeitos adversos , Pneumocefalia/diagnóstico por imagem , Pneumocefalia/etiologia , Pneumocefalia/terapia , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Globo Pálido/diagnóstico por imagem , Globo Pálido/cirurgia , Movimento
14.
PeerJ ; 12: e17228, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38618564

RESUMO

Background: Driving is a complex skill involving various cognitive activities. Previous research has explored differences in the brain structures related to the navigational abilities of drivers compared to non-drivers. However, it remains unclear whether changes occur in the structures associated with low-level sensory and higher-order cognitive abilities in drivers. Methods: Gray matter volume, assessed via voxel-based morphometry analysis of T1-weighted images, is considered a reliable indicator of structural changes in the brain. This study employs voxel-based morphological analysis to investigate structural differences between drivers (n = 22) and non-drivers (n = 20). Results: The results indicate that, in comparison to non-drivers, drivers exhibit significantly reduced gray matter volume in the middle occipital gyrus, middle temporal gyrus, supramarginal gyrus, and cerebellum, suggesting a relationship with driving-related experience. Furthermore, the volume of the middle occipital gyrus, and middle temporal gyrus, is found to be marginally negative related to the years of driving experience, suggesting a potential impact of driving experience on gray matter volume. However, no significant correlations were observed between driving experiences and frontal gray matter volume. Conclusion: These findings suggest that driving skills and experience have a pronounced impact on the cortical areas responsible for low-level sensory and motor processing. Meanwhile, the influence on cortical areas associated with higher-order cognitive function appears to be minimal.


Assuntos
Encéfalo , Substância Cinzenta , Substância Cinzenta/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Cerebelo , Cognição , Lobo Occipital/diagnóstico por imagem
15.
J Med Virol ; 96(4): e29590, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38619024

RESUMO

Our study investigates the molecular link between COVID-19 and Alzheimer's disease (AD). We aim to elucidate the mechanisms by which COVID-19 may influence the onset or progression of AD. Using bioinformatic tools, we analyzed gene expression datasets from the Gene Expression Omnibus (GEO) database, including GSE147507, GSE12685, and GSE26927. Intersection analysis was utilized to identify common differentially expressed genes (CDEGs) and their shared biological pathways. Consensus clustering was conducted to group AD patients based on gene expression, followed by an analysis of the immune microenvironment and variations in shared pathway activities between clusters. Additionally, we identified transcription factor-binding sites shared by CDEGs and genes in the common pathway. The activity of the pathway and the expression levels of the CDEGs were validated using GSE164805 and GSE48350 datasets. Six CDEGs (MAL2, NECAB1, SH3GL2, EPB41L3, MEF2C, and NRGN) were identified, along with a downregulated pathway, the endocannabinoid (ECS) signaling pathway, common to both AD and COVID-19. These CDEGs showed a significant correlation with ECS activity (p < 0.05) and immune functions. The ECS pathway was enriched in healthy individuals' brains and downregulated in AD patients. Validation using GSE164805 and GSE48350 datasets confirmed the differential expression of these genes in COVID-19 and AD tissues. Our findings reveal a potential pathogenetic link between COVID-19 and AD, mediated by CDEGs and the ECS pathway. However, further research and multicenter evidence are needed to translate these findings into clinical applications.


Assuntos
Doença de Alzheimer , COVID-19 , Humanos , COVID-19/genética , Doença de Alzheimer/genética , Endocanabinoides , Encéfalo , Análise por Conglomerados , Proteínas Proteolipídicas Associadas a Linfócitos e Mielina , Proteínas dos Microfilamentos
16.
J Vis Exp ; (205)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38619261

RESUMO

Gene therapy is a powerful technology to deliver new genes to a patient for the treatment of disease, be it to introduce a functional gene, inactivate a toxic gene, or provide a gene whose product can modulate the biology of the disease. The delivery method for the therapeutic vector can take many forms, ranging from intravenous infusion for systemic delivery to direct injection into the target tissue. For neurodegenerative disorders, it is often desirable to skew transduction towards the brain and/or spinal cord. The least invasive approach to target the entire central nervous system involves injection into the cerebrospinal fluid (CSF), allowing the therapeutic to reach a large fraction of the central nervous system. The safest approach to deliver a vector into the CSF is the lumbar intrathecal injection, where a needle is introduced into the lumbar cistern of the spinal cord. This technique, also known as a lumbar puncture, has been widely used in neonatal and adult rodents and in large animal models. While the technique is similar across species and developmental stages, subtle differences in size, structure, and elasticity of tissues surrounding the intrathecal space require accommodations in the approach. This article describes a method for performing lumbar puncture in juvenile rats to deliver an adeno-associated serotype 9 vector. Here, 25-35 µL of vector were injected into the lumbar cistern, and a green fluorescent protein (GFP) reporter was used to evaluate the transduction profile resulting from each injection. The benefits and challenges of this approach are discussed.


Assuntos
Sistema Nervoso Central , Medula Espinal , Adulto , Ratos , Animais , Humanos , Injeções , Acomodação Ocular , Encéfalo
17.
J Vis Exp ; (205)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38619271

RESUMO

Over the past decade, single-cell transcriptomics has significantly evolved and become a standard laboratory method for simultaneous analysis of gene expression profiles of individual cells, allowing the capture of cellular diversity. In order to overcome limitations posed by difficult-to-isolate cell types, an alternative approach aiming at recovering single nuclei instead of intact cells can be utilized for sequencing, making transcriptome profiling of individual cells universally applicable. These techniques have become a cornerstone in the study of brain organoids, establishing them as models of the developing human brain. Leveraging the potential of single-cell and single-nucleus transcriptomics in brain organoid research, this protocol presents a step-by-step guide encompassing key procedures such as organoid dissociation, single-cell or nuclei isolation, library preparation and sequencing. By implementing these alternative approaches, researchers can obtain high-quality datasets, enabling the identification of neuronal and non-neuronal cell types, gene expression profiles, and cell lineage trajectories. This facilitates comprehensive investigations into cellular processes and molecular mechanisms shaping brain development.


Assuntos
Encéfalo , Transcriptoma , Humanos , Organoides , Perfilação da Expressão Gênica , Núcleo Celular
18.
J Vis Exp ; (205)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38619274

RESUMO

Melanoma-associated leptomeningeal disease (M-LMD) occurs when circulating tumor cells (CTCs) enter into the cerebral spinal fluid (CSF) and colonize the meninges, the membrane layers that protect the brain and the spinal cord. Once established, the prognosis for M-LMD patients is dismal, with overall survival ranging from weeks to months. This is primarily due to a paucity in our understanding of the disease and, as a consequence, the availability of effective treatment options. Defining the underlying biology of M-LMD will significantly improve the ability to adapt available therapies for M-LMD treatment or design novel inhibitors for this universally fatal disease. A major barrier, however, lies in obtaining sufficient quantities of CTCs from the patient-derived CSF (CSF-CTCs) to conduct preclinical experiments, such as molecular characterization, functional analysis, and in vivo efficacy studies. Culturing CSF-CTCs ex vivo has also proven to be challenging. To address this, a novel protocol for the culture of patient-derived M-LMD CSF-CTCs ex vivo and in vivo is developed. The incorporation of conditioned media produced by human meningeal cells (HMCs) is found to be critical to the procedure. Cytokine array analysis reveals that factors produced by HMCs, such as insulin-like growth factor-binding proteins (IGFBPs) and vascular endothelial growth factor-A (VEGF-A), are important in supporting CSF-CTC survival ex vivo. Here, the usefulness of the isolated patient-derived CSF-CTC lines is demonstrated in determining the efficacy of inhibitors that target the insulin-like growth factor (IGF) and mitogen-activated protein kinase (MAPK) signaling pathways. In addition, the ability to intrathecally inoculate these cells in vivo to establish murine models of M-LMD that can be employed for preclinical testing of approved or novel therapies is shown. These tools can help unravel the underlying biology driving CSF-CTC establishment in the meninges and identify novel therapies to reduce the morbidity and mortality associated with M-LMD.


Assuntos
Melanoma , Células Neoplásicas Circulantes , Humanos , Animais , Camundongos , Fator A de Crescimento do Endotélio Vascular , Encéfalo , Membrana Celular
19.
Nat Commun ; 15(1): 3226, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622132

RESUMO

The tumor microenvironment plays a crucial role in determining response to treatment. This involves a series of interconnected changes in the cellular landscape, spatial organization, and extracellular matrix composition. However, assessing these alterations simultaneously is challenging from a spatial perspective, due to the limitations of current high-dimensional imaging techniques and the extent of intratumoral heterogeneity over large lesion areas. In this study, we introduce a spatial proteomic workflow termed Hyperplexed Immunofluorescence Imaging (HIFI) that overcomes these limitations. HIFI allows for the simultaneous analysis of > 45 markers in fragile tissue sections at high magnification, using a cost-effective high-throughput workflow. We integrate HIFI with machine learning feature detection, graph-based network analysis, and cluster-based neighborhood analysis to analyze the microenvironment response to radiation therapy in a preclinical model of glioblastoma, and compare this response to a mouse model of breast-to-brain metastasis. Here we show that glioblastomas undergo extensive spatial reorganization of immune cell populations and structural architecture in response to treatment, while brain metastases show no comparable reorganization. Our integrated spatial analyses reveal highly divergent responses to radiation therapy between brain tumor models, despite equivalent radiotherapy benefit.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Animais , Camundongos , Proteômica , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/patologia , Glioblastoma/diagnóstico por imagem , Glioblastoma/radioterapia , Glioblastoma/patologia , Encéfalo/patologia , Imunofluorescência , Microambiente Tumoral
20.
Sci Rep ; 14(1): 8701, 2024 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622193

RESUMO

Honey bees are social insects, and each colony member has unique morphological and physiological traits associated with their social tasks. Previously, we identified a long non-coding RNA from honey bees, termed Nb-1, whose expression in the brain decreases associated with the age-polyethism of workers and is detected in some neurosecretory cells and octopaminergic neurons, suggesting its role in the regulation of worker labor transition. Herein, we investigated its spatially and temporary-regulated/sex-specific expression. Nb-1 was expressed as an abundant maternal RNA during oogenesis and embryogenesis in both sexes. In addition, Nb-1 was expressed preferentially in the proliferating neuroblasts of the mushroom bodies (a higher-order center of the insect brain) in the pupal brains, suggesting its role in embryogenesis and mushroom body development. On the contrary, Nb-1 was expressed in a drone-specific manner in the pupal and adult retina, suggesting its role in the drone visual development and/or sense. Subcellular localization of Nb-1 in the brain during development differed depending on the cell type. Considering that Nb-1 is conserved only in Apidae, our findings suggest that Nb-1 potentially has pleiotropic functions in the expression of multiple developmental, behavioral, and physiological traits, which are closely associated with the honey bee lifecycle.


Assuntos
RNA Longo não Codificante , Feminino , Masculino , Abelhas/genética , Animais , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Nióbio , Encéfalo/fisiologia , Neurônios/fisiologia , Cabeça , Pupa
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