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1.
Front Oncol ; 14: 1343533, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38410101

RESUMO

Background: Uterine leiomyosarcoma(uLMS) is a rare malignant tumor with low clinical specificity and poor prognosis.There are many studies related to uLMS, however, there is still a lack of metrological analyses with generalization. This study provides a bibliometric study of uLMS. Methods and materials: We chose the Web of Science (WoS) as our main database due to its extensive interdisciplinary coverage. We specifically focused on the literature from the last 20 years to ensure relevance and practicality. By utilizing the WOS core dataset and leveraging the R package "bibliometric version 4.1.0" and Citespace, we performed a comprehensive bibliometric analysis. This allowed us to pinpoint research hotspots and create visual representations, resulting in the retrieval of 2489 pertinent articles. Results: This literature review covers 2489 articles on uterine leiomyosarcoma (uLMS) from the past 20 years. Key findings include an average annual publication rate of 8.75, with a 6.07% yearly growth rate and an average citation count of 17.22. Core+Zone 2 sources contributed 1079 articles and 207 reviews, displaying a 4.98% annual growth rate. The analysis identified top journals, influential authors, and core sources, such as the prevalence of publications from the United States and the dominance of GYNECOLOGIC ONCOLOGY and HENSLEY ML. Bradford's Law and Lotka's Law highlighted core sources and author productivity, respectively. Thematic mapping and factorial analysis revealed research clusters, including etiology, diagnosis, treatment advancements, and surgical approaches, with prominent themes such as gemcitabine and docetaxel. Overall, this comprehensive analysis provides insights into uLMS literature trends and influential factors. Conclusion: This thorough bibliometric analysis, in its whole, illuminates the field's guiding principles while also revealing the subtle patterns within the uLMS literature. The knowledge gained here contributes to the current discussion in uLMS and related scientific fields and provides a solid basis for future research paths.

2.
Hepatol Int ; 17(4): 915-926, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37012542

RESUMO

BACKGROUND: The evidence of transcatheter arterial chemoembolization (TACE) plus tyrosine kinase inhibitor and immune checkpoint inhibitor in unresectable hepatocellular carcinoma (HCC) was limited. This study aimed to evaluate the role of TACE plus apatinib (TACE + A) and TACE combined with apatinib plus camrelizumab (TACE + AC) in patients with unresectable HCC. METHODS: This study retrospectively reviewed patients with unresectable HCC who received TACE + A or TACE + AC in 20 centers of China from January 1, 2019 to June 31, 2021. Propensity score matching (PSM) at 1:1 was performed to reduce bias. Treatment-related adverse events (TRAEs), overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and disease control rate (DCR) were collected. RESULTS: A total of 960 eligible patients with HCC were included in the final analysis. After PSM, there were 449 patients in each group, and the baseline characteristics were balanced between two groups. At data cutoff, the median follow-up time was 16.3 (range: 11.9-21.4) months. After PSM, the TACE + AC group showed longer median OS (24.5 vs 18.0 months, p < 0.001) and PFS (10.8 vs 7.7 months, p < 0.001) than the TACE + A group; the ORR (49.9% vs 42.5%, p = 0.002) and DCR (88.4% vs 84.0%, p = 0.003) of the TACE + AC group were also higher than those in the TACE + A group. Fever, pain, hypertension and hand-foot syndrome were the more common TRAEs in two groups. CONCLUSIONS: Both TACE plus apatinib and TACE combined with apatinib plus camrelizumab were feasible in patients with unresectable HCC, with manageable safety profiles. Moreover, TACE combined with apatinib plus camrelizumab showed additional benefit.


Assuntos
Antineoplásicos , Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Estudos Retrospectivos , Antineoplásicos/uso terapêutico , Terapia Combinada
3.
Mol Oncol ; 14(11): 2775-2786, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32920960

RESUMO

It is well known that different racial groups have significantly different incidence and mortality rates for certain cancers. It has been suggested that biological factors play a major role in these cancer racial disparities. Previous studies on the biological factors contributing to cancer racial disparity have generated a very large number of candidate factors, although there is modest agreement among the results of the different studies. Here, we performed an integrative analysis using genomic data of 21 cancer types from TCGA, GTEx, and the 1000 Genomes Project to identify biological factors contributing to racial disparity in cancer. We also built a companion website with additional results for cancer researchers to freely mine. Our study identified genes, gene families, and pathways displaying similar differential expression patterns between different racial groups across multiple cancer types. Among them, XKR9 gene expression was found to be significantly associated with overall survival for all cancers combined as well as for several individual cancers. Our results point to the interesting hypothesis that XKR9 could be a novel drug target for cancer immunotherapy. Bayesian network modeling showed that XKR9 is linked to important cancer-related genes, including FOXM1, cyclin B1, and RB1CC1 (RB1 regulator). In addition, metabolic pathways, neural signaling pathways, and several cancer-related gene families were found to be significantly associated with cancer racial disparities for multiple cancer types. Single nucleotide polymorphisms (SNPs) discovered through integrating data from the TCGA, GTEx, and 1000 Genomes databases provide biologists the opportunity to test highly promising, targeted hypotheses to gain a deeper understanding of the genetic drivers of cancer racial disparity and cancer biology in general.


Assuntos
Neoplasias/genética , Proteínas Reguladoras de Apoptose/genética , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Genômica , Humanos , Incidência , Proteínas de Membrana/genética , Neoplasias/epidemiologia , Polimorfismo de Nucleotídeo Único , Fatores Raciais , Transcriptoma
4.
iScience ; 23(3): 100942, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32179471

RESUMO

Many animals, including humans, have evolved to live and move in groups. In humans, disrupted social interactions are a fundamental feature of many psychiatric disorders. However, we know little about how genes regulate social behavior. Zebrafish may serve as a powerful model to explore this question. By comparing the behavior of wild-type fish with 90 mutant lines, we show that mutations of genes associated with human psychiatric disorders can alter the collective behavior of adult zebrafish. We identify three categories of behavioral variation across mutants: "scattered," in which fish show reduced cohesion; "coordinated," in which fish swim more in aligned schools; and "huddled," in which fish form dense but disordered groups. Changes in individual interaction rules can explain these differences. This work demonstrates how emergent patterns in animal groups can be altered by genetic changes in individuals and establishes a framework for understanding the fundamentals of social information processing.

5.
Curr Biol ; 29(15): 2541-2546.e3, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31327717

RESUMO

Mating and flight from threats are innate behaviors that enhance species survival [1, 2]. Stimuli to these behaviors often are contemporaneous and conflicting [3, 4]. Both how such conflicts are resolved and where in the brain such decisions are made are poorly understood. For teleosts, olfactory stimuli are key elements of mating and threat responses [5-7]. For example, zebrafish manifest a stereotypical escape response when exposed to an alarm substance released from injured conspecific skin ("skin extract") [8, 9]. We find that when mating, fish ignore this threatening stimulus. Water conditioned by the mating fish ("mating water") suffices to suppress much of the alarm-response behavior. By 2-photon imaging of calcium transients [10], we mapped the regions of the brain responding to skin extract and to mating water. In the telencephalon, we found regions where the responses overlap, one region (medial Dp) to be predominantly activated by skin extract, and another, Vs, to be predominantly activated by mating water. When mating water and skin extract were applied simultaneously, the alarm-specific response was suppressed, while the mating-water-specific response was retained, corresponding to the dominance of mating over flight behavior. The choice made, for reproduction over escape, is opposite to that of mammals, presumably reflecting how the balance affects species survival.


Assuntos
Reação de Fuga , Odorantes , Comportamento Sexual Animal , Telencéfalo/fisiologia , Peixe-Zebra/fisiologia , Animais , Água
6.
iScience ; 17: 325-333, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31325771

RESUMO

Dopamine transporter (SLC6A3) deficiency causes infantile Parkinson disease, for which there is no effective therapy. We have explored the effects of genetically deleting SLC6A3 in zebrafish. Unlike the wild-type, slc6a3-/- fish hover near the tank bottom, with a repetitive digging-like behavior. slc6a3-/- fish manifest pruning and cellular loss of particular tyrosine hydroxylase-immunoreactive neurons in the midbrain. Clozapine, an effective therapeutic for treatment-resistant schizophrenia, rescues the abnormal behavior of slc6a3-/- fish. Clozapine also reverses the abnormalities in the A8 region of the mutant midbrain. By RNA sequencing analysis, clozapine increases the expression of erythropoietin pathway genes. Transgenic over-expression of erythropoietin in neurons of slc6a3-/- fish partially rescues the mutant behavior, suggesting a potential mechanistic basis for clozapine's efficacy.

7.
Sci Rep ; 8(1): 5934, 2018 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-29651008

RESUMO

Solution processing of ternary and multinary amorphous metal oxide insulators at processing temperatures below 250 °C remains challenging. Here, we report that the synthesis of a hybrid cluster structure, where the metal oxide core is coordinated by ligands and the different metal elements are incorporated into one core, is an effective strategy for the low-temperature processing of the ternary LaZrO insulator. Solvothermal treatment at 160-180 °C facilitated the development of a cluster structure. From the cluster precursor, high-performance insulating LaZrO films were obtained at 200 °C under the irradiation of ultraviolet light. The analysis data indicate that the solvothermal treatment led to structural unification of the metal oxide network and facilitated stabilization of the residual organic ingredients in UV annealing, which both contributed to the improved insulating properties of LaZrO. Together with a solution-processed channel, we have been able to fabricate LaZrO-based transistors at 200 °C. Though the channel material has not been optimized, the transistor have showed a low gate leakage current around 10 pA at an operating voltage of 15 V, an on/off ratio of near 106, a field-effect saturation mobility of 0.37 cm2 V-1 s-1, a subthreshold swing factor of 0.61 V decade-1.

8.
Sci Rep ; 6: 29682, 2016 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-27411971

RESUMO

In the solution processing of oxide electronics, the structure of metal-organic precursors in solution and their effect on processability and on the final structure and properties of the oxide have rarely been studied. We have observed that hybrid clusters, having inorganic cores coordinated by organic ligands, are the typical form of metal-organic precursor structures. For insulating ternary LaZrO, improved synthesis of the cluster precursor under solvothermal conditions led to low-temperature deposition of the film at 200 °C, as we will report in another paper. In the current paper, we first briefly show that solvothermal synthesis of the precursor resulted in significantly improved insulating properties (e.g., two orders lower leakage current) of high-temperature-annealed films, and then focus on the structural analysis of the cluster precursors and annealed solids and relate the results to the significant improvement of properties by solvothermal treatment of solutions. A change in the cluster core toward structural unification was brought about by solvothermal treatment, resulting in higher uniformity and higher stability of clusters. The final structure of the material maintained the features of the core structure in solution, even after annealing at high temperatures. These results demonstrate the key role played by designing cluster structure in solution.

9.
Planta Med ; 80(13): 1107-12, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25127022

RESUMO

A novel heteroglycan, Cordyceps sinensis polysaccharide 1 (molecular weight 1 17 × 10(5) Da), was isolated and purified from mycelia of the fungus C. sinensis obtained by solid-state culture. Structural characterization by chemical analysis, GC-MS, FTIR, and NMR spectroscopy showed that C. sinensis polysaccharide 1 was mainly composed of (1 → 6)-linked α-D-Glc and α-D-Gal, with minor ß-(1 → 4)-D-Xyl and ß-(1 → 4)-D-Man residues probably located in the side chains with a trace amount of α-(1 → 3)-L-Rha residue. In biological assays, C. sinensis polysaccharide 1 significantly inhibited proliferation of sarcoma 180 cells and induced apoptosis in a dose-dependent manner. Further studies will elucidate the antitumor mechanism of C. sinensis polysaccharide 1 and promote its utilization for the development of novel, effective anticancer drugs.


Assuntos
Antineoplásicos/farmacologia , Cordyceps/química , Polissacarídeos/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Micélio/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Sarcoma 180/tratamento farmacológico , Sarcoma 180/patologia , Espectroscopia de Infravermelho com Transformada de Fourier
10.
Beilstein J Nanotechnol ; 4: 793-804, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24367748

RESUMO

This paper describes a facile approach to a biomimetic rapid fabrication of ultrathin silica nanotubes with a highly uniform diameter of 10 nm and inner hollow of around 3 nm. The synthesis is carried out through a spontaneous polycondensation of alkoxysilane on polyamine crystalline fibrils that were conveniently produced from the neutralization of a solution of protonated linear polyethyleneimine (LPEI-H(+)) by alkali compounds. A simple mixing the fibrils with alkoxysilane in aqueous solution allowed for the rapid formation of silica to produce LPEI@silica hybrid nanotubes. These 10-nm nanotubes were hierarchically organized in a mat-like morphology with a typical size of 1-2 micrometers. The subsequent removal of organic LPEI via calcination resulted in silica nanotubes that keep this morphology. The morphology, the structure, the pore properties and the formation mechanism of the silica nanotubes were carefully investigated with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller measurements (BET), and X-ray diffraction (XRD). Detailed studies demonstrated that the formation of the nanotubes depends on the molar ratio of [OH]/[CH2CH2NH] during the neutralization as well as on the basicity of the alkali compound and on the concentration of the silica source. The synthesis of silica nanotubes established here could be easily applied to a fabrication on the kilogram scale. Silica nanotubes that were obtained from the calcination of hybrid nanotubes of LPEI@silica in an N2 atmosphere showed a distinct photoluminescence centered at 540 nm with a maximum excitation wavelength of 320 nm. Furthermore, LPEI@silica hybrid nanotubes were applied to create silica-carbon composite nanotubes by alternative adsorption of ionic polymers and subsequent carbonization.

11.
Nat Neurosci ; 16(11): 1678-86, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24077563

RESUMO

Robustness of neuronal activity patterns against variations in input intensity is critical for neuronal computations. We found that odor representations in the olfactory bulb were stabilized by interneurons that were densely coupled to the output neurons by electrical and GABAergic synapses. This interneuron network modulated responses of output neurons as a function of stimulus intensity in two ways: it globally boosted responses to weak odors, but attenuated responses to strong odors, and it increased the sensitivity of some output neurons, but decreased the sensitivity of others. These effects are closely related to strategies used in engineering to increase dynamic range. Together, they maintained not only the mean, but also the distribution, of activity across the population of output neurons within narrow limits, which is important for pattern classification. Neuronal circuits in the olfactory bulb therefore stabilize combinatorial sensory representations against variations in stimulus intensity by generic mechanisms.


Assuntos
Interneurônios/fisiologia , Modelos Neurológicos , Inibição Neural/fisiologia , Odorantes , Bulbo Olfatório/citologia , Condutos Olfatórios/fisiologia , Olfato , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Animais Geneticamente Modificados , Cálcio/metabolismo , Simulação por Computador , Feminino , Proteínas Luminescentes/genética , Masculino , Proteínas do Tecido Nervoso/genética , Inibição Neural/efeitos dos fármacos , Dinâmica não Linear , Técnicas de Patch-Clamp , Estimulação Luminosa , Proteínas R-SNARE/genética , Proteínas R-SNARE/metabolismo , Estatísticas não Paramétricas , Peixe-Zebra , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
12.
Artigo em Inglês | MEDLINE | ID: mdl-23641200

RESUMO

Complex motor behaviors are thought to be coordinated by networks of brain nuclei that may control different elementary motor programs. Transparent zebrafish larvae offer the opportunity to analyze the functional organization of motor control networks by optical manipulations of neuronal activity during behavior. We examined motor behavior in transgenic larvae expressing channelrhodopsin-2 throughout many neurons in the brain. Wide-field optical stimulation triggered backward and rotating movements caused by the repeated execution of J-turns, a specific motor program that normally occurs during prey capture. Although optically-evoked activity was widespread, behavioral responses were highly coordinated and lateralized. 3-D mapping of behavioral responses to local optical stimuli revealed that J-turns can be triggered specifically in the anterior-ventral optic tectum (avOT) and/or the adjacent pretectum. These results suggest that the execution of J-turns is controlled by a small group of neurons in the midbrain that may act as a command center. The identification of a brain area controlling a defined motor program involved in prey capture is a step toward a comprehensive analysis of neuronal circuits mediating sensorimotor behaviors of zebrafish.


Assuntos
Mesencéfalo/fisiologia , Atividade Motora/fisiologia , Desempenho Psicomotor/fisiologia , Colículos Superiores/fisiologia , Animais , Animais Geneticamente Modificados , Vias Neurais/fisiologia , Estimulação Luminosa/métodos , Peixe-Zebra
13.
Nat Protoc ; 7(7): 1410-25, 2012 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-22743832

RESUMO

Optogenetic approaches allow the manipulation of neuronal activity patterns in space and time by light, particularly in small animals such as zebrafish. However, most techniques cannot control neuronal activity independently at different locations. Here we describe equipment and provide a protocol for single-photon patterned optical stimulation of neurons using a digital micromirror device (DMD). This method can create arbitrary spatiotemporal light patterns with spatial and temporal resolutions in the micrometer and submillisecond range, respectively. Different options to integrate a DMD into a multiphoton microscope are presented and compared. We also describe an ex vivo preparation of the adult zebrafish head that greatly facilitates optogenetic and other experiments. After assembly, the initial alignment takes about one day and the zebrafish preparation takes <30 min. The method has previously been used to activate channelrhodopsin-2 and manipulate oscillatory synchrony among spatially distributed neurons in the zebrafish olfactory bulb. It can be adapted easily to a wide range of other species, optogenetic probes and scientific applications.


Assuntos
Luz , Neurobiologia/instrumentação , Neurobiologia/métodos , Neurônios/fisiologia , Dispositivos Ópticos , Fótons , Peixe-Zebra/fisiologia , Animais , Neurônios/citologia , Óptica e Fotônica/métodos , Estimulação Luminosa
14.
J Neurosci ; 32(20): 6830-40, 2012 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-22593052

RESUMO

In the olfactory bulb, the modulatory neurotransmitter dopamine (DA) is coexpressed with GABA by local interneurons, but its role in odor processing remains obscure. We examined functions of DA mediated by D2-like receptors in the olfactory bulb of adult zebrafish by pharmacology, whole-cell recordings, calcium imaging, and optogenetics. Bath application of DA had no detectable effect on odorant-evoked sensory input. DA directly hyperpolarized mitral cells (MCs) via D2-like receptors and slightly increased their response gain. Consistent with this effect on input-output functions of MCs, small odorant responses were suppressed, whereas strong responses were enhanced in the presence of DA. These effects increased the root-mean-square contrast of population activity patterns but did not reduce their correlations. Optical stimulation of interneurons expressing channelrhodopsin-2 evoked fast GABAergic inhibitory currents in mitral cells but failed to activate D2 receptor-mediated currents when stimuli were short. Prolonged stimulus trains, however, activated a slow hyperpolarizing current that was blocked by an antagonist of D2-like receptors. GABA and DA are therefore both released from interneurons by electrical activity and hyperpolarize MCs, but D2-dependent dopaminergic effects occur on slower timescales. Additional effects of DA may be mediated by D1-like receptors. These results indicate that DA acts on D2-like receptors via asynchronous release and/or volume transmission and implicate DA in the slow adaptation of circuit function. The shift of the membrane potential away from spike threshold could adapt mitral cells to background input without compromising their sensitivity.


Assuntos
Dopamina/fisiologia , Bulbo Olfatório/fisiologia , Percepção Olfatória/fisiologia , Neurônios Receptores Olfatórios/fisiologia , Receptores de Dopamina D2/fisiologia , Animais , Animais Geneticamente Modificados , Dopamina/farmacologia , Antagonistas dos Receptores de Dopamina D2 , Técnicas In Vitro , Interneurônios/fisiologia , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Modelos Neurológicos , Imagem Molecular/métodos , Bulbo Olfatório/efeitos dos fármacos , Técnicas de Patch-Clamp/métodos , Estimulação Luminosa/métodos , Rodopsina/genética , Rodopsina/metabolismo , Estimulação Química , Fatores de Tempo , Peixe-Zebra
15.
Nature ; 479(7374): 493-8, 2011 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-22080956

RESUMO

Neuronal activity patterns contain information in their temporal structure, indicating that information transfer between neurons may be optimized by temporal filtering. In the zebrafish olfactory bulb, subsets of output neurons (mitral cells) engage in synchronized oscillations during odour responses, but information about odour identity is contained mostly in non-oscillatory firing rate patterns. Using optogenetic manipulations and odour stimulation, we found that firing rate responses of neurons in the posterior zone of the dorsal telencephalon (Dp), a target area homologous to olfactory cortex, were largely insensitive to oscillatory synchrony of mitral cells because passive membrane properties and synaptic currents act as low-pass filters. Nevertheless, synchrony influenced spike timing. Moreover, Dp neurons responded primarily during the decorrelated steady state of mitral cell activity patterns. Temporal filtering therefore tunes Dp neurons to components of mitral cell activity patterns that are particularly informative about precise odour identity. These results demonstrate how temporal filtering can extract specific information from multiplexed neuronal codes.


Assuntos
Modelos Neurológicos , Neurônios/fisiologia , Odorantes/análise , Bulbo Olfatório/citologia , Bulbo Olfatório/fisiologia , Peixe-Zebra/fisiologia , Potenciais de Ação , Animais , Condutos Olfatórios/fisiologia , Estimulação Luminosa , Estimulação Física , Fatores de Tempo
16.
Curr Biol ; 20(8): R371-81, 2010 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-21749961

RESUMO

A central goal of modern neuroscience is to obtain a mechanistic understanding of higher brain functions under healthy and diseased conditions. Addressing this challenge requires rigorous experimental and theoretical analysis of neuronal circuits. Recent advances in optogenetics, high-resolution in vivo imaging, and reconstructions of synaptic wiring diagrams have created new opportunities to achieve this goal. To fully harness these methods, model organisms should allow for a combination of genetic and neurophysiological approaches in vivo. Moreover, the brain should be small in terms of neuron numbers and physical size. A promising vertebrate organism is the zebrafish because it is small, it is transparent at larval stages and it offers a wide range of genetic tools and advantages for neurophysiological approaches. Recent studies have highlighted the potential of zebrafish for exhaustive measurements of neuronal activity patterns, for manipulations of defined cell types in vivo and for studies of causal relationships between circuit function and behavior. In this article, we summarize background information on the zebrafish as a model in modern systems neuroscience and discuss recent results.


Assuntos
Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Modelos Animais , Rede Nervosa/anatomia & histologia , Rede Nervosa/fisiologia , Peixe-Zebra/anatomia & histologia , Peixe-Zebra/fisiologia , Animais , Comportamento Animal/fisiologia , Expressão Gênica , Neurociências/métodos , Condutos Olfatórios/anatomia & histologia , Condutos Olfatórios/fisiologia , Vias Visuais/anatomia & histologia , Vias Visuais/fisiologia , Peixe-Zebra/genética
17.
Artigo em Inglês | MEDLINE | ID: mdl-20126518

RESUMO

The conditional expression of transgenes at high levels in sparse and specific populations of neurons is important for high-resolution optogenetic analyses of neuronal circuits. We explored two complementary methods, viral gene delivery and the iTet-Off system, to express transgenes in the brain of zebrafish. High-level gene expression in neurons was achieved by Sindbis and Rabies viruses. The Tet system produced strong and specific gene expression that could be modulated conveniently by doxycycline. Moreover, transgenic lines showed expression in distinct, sparse and stable populations of neurons that appeared to be subsets of the neurons targeted by the promoter driving the Tet-activator. The Tet system therefore provides the opportunity to generate libraries of diverse expression patterns similar to gene trap approaches or the thy-1 promoter in mice, but with the additional possibility to pre-select cell types of interest. In transgenic lines expressing channelrhodopsin-2, action potential firing could be precisely controlled by two-photon stimulation at low laser power, presumably because the expression levels of the Tet-controlled genes were high even in adults. In channelrhodopsin-2-expressing larvae, optical stimulation with a single blue LED evoked distinct swimming behaviors including backward swimming. These approaches provide new opportunities for the optogenetic dissection of neuronal circuit structure and function.

18.
PLoS One ; 2(6): e533, 2007 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-17579707

RESUMO

To identify the underlying reason for the controversial performance of tetracycline (Tet)-controlled regulated gene expression in mammalian neurons, we investigated each of the three components that comprise the Tet inducible systems, namely tetracyclines as inducers, tetracycline-transactivator (tTA) and reverse tTA (rtTA), and tTA-responsive promoters (P(tets)). We have discovered that stably integrated P(tet) becomes functionally silenced in the majority of neurons when it is inactive during development. P(tet) silencing can be avoided when it is either not integrated in the genome or stably-integrated with basal activity. Moreover, long-term, high transactivator levels in neurons can often overcome integration-induced P(tet) gene silencing, possibly by inducing promoter accessibility.


Assuntos
Encéfalo/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Regulação da Expressão Gênica , Inativação Gênica/efeitos dos fármacos , Tetraciclina/farmacologia , Transativadores/genética , Animais , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Hibridização In Situ , Luciferases/genética , Luciferases/metabolismo , Camundongos , Camundongos Transgênicos , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas/genética , Transativadores/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos
20.
Langmuir ; 22(1): 332-7, 2006 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-16378440

RESUMO

We have developed a technique for the site-selective electroless deposition of Cu on poly(ethylene terephthalate) (PET) substrate modified with an organic self-assembled monolayer (SAM). The PET substrate was first modified with a silica-like layer by being dip-coated in an acetone solution of 3-aminopropyltrimethoxysilane and treated with UV light. The PET substrate was further modified with thiol groups using a 3-mercaptopropyltrimethoxysilane-SAM and then irradiated by UV light through a photomask to prepare thiol-group regions and OH-group regions. Cu was then deposited on only the thiol-group regions of the substrate by electroless deposition in a neutral solution with no catalysts by using dimethylamineborane as a reducing reagent. This site-selective deposition process can control the deposition conditions by an organic thin film fabricated on a surface-modified PET substrate, and thus can be applied to other low heat-resistant substrates.

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