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1.
J Physiol ; 601(2): 335-353, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36515167

RESUMO

Layer V neurons in the primary motor cortex (M1) are important for motor skill learning. Since pretreatment of either CNQX or APV in rat M1 layer V impaired rotor rod learning, we analysed training-induced synaptic plasticity by whole-cell patch-clamp technique in acute brain slices. Rats trained for 1 day showed a decrease in small inhibitory postsynaptic current (mIPSC) frequency and an increase in the paired-pulse ratio of evoked IPSCs, suggesting a transient decrease in presynaptic GABA release in the early phase. Rats trained for 2 days showed an increase in miniature excitatory postsynaptic current (mEPSC) amplitudes/frequency and elevated AMPA/NMDA ratios, suggesting a long-term strengthening of AMPA receptor-mediated excitatory synapses. Importantly, rotor rod performance in trained rats was correlated with the mean mEPSC amplitude and the frequency obtained from that animal. In current-clamp analysis, 1-day-trained rats transiently decreased the current-induced firing rate, while 2-day-trained rats returned to pre-training levels, suggesting dynamic changes in intrinsic properties. Furthermore, western blot analysis of layer V detected decreased phosphorylation of Ser408-409 in GABAA receptor ß3 subunits in 1-day-trained rats, and increased phosphorylation of Ser831 in AMPA receptor GluA1 subunits in 2-day-trained rats. Finally, live-imaging analysis of Thy1-YFP transgenic mice showed that the training rapidly recruited a substantial number of spines for long-term plasticity in M1 layer V neurons. Taken together, these results indicate that motor training induces complex and diverse plasticity in M1 layer V pyramidal neurons. KEY POINTS: Here we examined motor training-induced synaptic and intrinsic plasticity of layer V pyramidal neurons in the primary motor cortex. The training reduced presynaptic GABA release in the early phase, but strengthened AMPA receptor-mediated excitatory synapses in the later phase: acquired motor performance after training correlated with the strength of excitatory synapses rather than inhibitory synapses. As to the intrinsic property, the training transiently decreased the firing rate in the early phase, but returned to pre-training levels in the later phase. Western blot analysis detected decreased phosphorylation of Ser408-409 in GABAA receptor ß3 subunits in the acute phase, and increased phosphorylation of Ser831 in AMPA receptor GluA1 subunits in the later phase. Live-imaging analysis of Thy1-YFP transgenic mice showed rapid and long-term spine plasticity in M1 layer V neurons, suggesting training-induced increases in self-entropy per spine.


Assuntos
Córtex Motor , Receptores de GABA-A , Camundongos , Ratos , Animais , Receptores de GABA-A/metabolismo , Receptores de AMPA/metabolismo , Córtex Motor/fisiologia , Células Piramidais/fisiologia , Sinapses/fisiologia , Plasticidade Neuronal/fisiologia , Ácido gama-Aminobutírico , Camundongos Transgênicos
2.
Cereb Cortex ; 29(5): 2183-2195, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30796817

RESUMO

The hippocampus is functionally heterogeneous between the dorsal and ventral subfields with left-right asymmetry. To determine the possible location of contextual memory, we performed an inhibitory avoidance task to analyze synaptic plasticity using slice patch-clamp technique. The training bilaterally increased the AMPA/NMDA ratio at dorsal CA3-CA1 synapses, whereas the training did not affect the ratio at ventral CA3-CA1 synapses regardless of the hemisphere. Moreover, sequential recording of miniature excitatory postsynaptic currents and miniature inhibitory postsynaptic currents from the same CA1 neuron clearly showed learning-induced synaptic plasticity. In dorsal CA1 neurons, the training dramatically strengthened both excitatory and inhibitory postsynaptic responses in both hemispheres, whereas the training did not promote the plasticity in either hemisphere in ventral CA1 neurons. Nonstationary fluctuation analysis further revealed that the training bilaterally increased the number of AMPA or GABAA receptor channels at dorsal CA1 synapses, but not at ventral CA1 synapses, suggesting functional heterogeneity of learning-induced receptor mobility. Finally, the performance clearly impaired by the bilateral microinjection of plasticity blockers in dorsal, but not ventral CA1 subfields, suggesting a crucial role for contextual learning. The quantification of synaptic diversity in specified CA1 subfields may help us to diagnose and evaluate cognitive disorders at the information level.


Assuntos
Região CA1 Hipocampal/fisiologia , Aprendizagem/fisiologia , Memória/fisiologia , Plasticidade Neuronal , Células Piramidais/fisiologia , Animais , Aprendizagem da Esquiva , Região CA3 Hipocampal/fisiologia , Masculino , Potenciais Pós-Sinápticos em Miniatura , Vias Neurais/fisiologia , Ratos Sprague-Dawley , Receptores de AMPA/fisiologia , Receptores de N-Metil-D-Aspartato/fisiologia
3.
Neuroscience ; 559: 54-63, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39209105

RESUMO

Layer V neurons in primary motor cortex (M1) are required for motor skill learning. We analyzed training-induced plasticity using a whole-cell slice patch-clamp technique with a rotor rod task, and found that training induces diverse changes in intrinsic properties and synaptic plasticity in M1 layer V neurons. Although the causal relationship between specific cellular changes and motor performance is unclear, by linking individual motor performance to cellular/synaptic functions, we identified several cellular and synaptic parameters that represent acquired motor skills. With respect to cellular properties, motor performance was positively correlated with resting membrane potential and fast afterhyperpolarization, but not with the membrane resistance, capacitance, or threshold. With respect to synaptic function, the performance was positively correlated with AMPA receptor-mediated postsynaptic currents, but not with GABAA receptor-mediated postsynaptic currents. With respect to live imaging analysis in Thy1-YFP mice, we further demonstrated a cross-correlation between motor performance, spine head volume, and self-entropy per spine. In the present study, we identified several changes in M1 layer V pyramidal neurons after motor training that represent acquired motor skills. Furthermore, training increased extracellular acetylcholine levels known to promote synaptic plasticity, which is correlated with individual motor performance. These results suggest that systematic control of specific intracellular parameters and enhancement of synaptic plasticity in M1 layer V neurons may be useful for improving motor skills.

6.
Vet Rec ; 161(25): 853-7, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18156594

RESUMO

Monoclonal antibodies (mAbs) against a recombinant carboxyl terminus of the 34 kDa protein of Mycobacterium paratuberculosis were produced in mice. Two of the mAbs cross-reacted with Mycobacterium avium and Mycobacterium intracellulare in both an elisa and immunoblot. The recombinant protein also reacted with polyclonal sera produced in rabbits against all three mycobacteria, indicating the presence of cross-reactive epitopes in the protein. To determine the reactivity of cattle sera against epitopes recognised by the mAbs, competition assays between bovine sera and the mAbs were carried out. Two mAbs were significantly inhibited by sera from cattle that were naturally infected with M paratuberculosis. The results indicate that epitopes on the carboxyl terminus of the 34 kDa protein common to M paratuberculosis, M avium and M intracellulare readily induce antibody production in naturally infected cattle. These epitopes reduce the diagnostic specificity of the carboxyl terminus of the 34 kDa protein, which was originally thought to contain only M paratuberculosis-specific epitopes.


Assuntos
Anticorpos Antibacterianos/imunologia , Proteínas de Bactérias/imunologia , Doenças dos Bovinos/diagnóstico , Epitopos de Linfócito B/imunologia , Mycobacterium/imunologia , Paratuberculose/diagnóstico , Animais , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/sangue , Anticorpos Monoclonais/imunologia , Antígenos de Bactérias/imunologia , Bovinos , Doenças dos Bovinos/imunologia , Linhagem Celular , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática/normas , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Immunoblotting/veterinária , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium avium/imunologia , Complexo Mycobacterium avium/imunologia , Mycobacterium avium subsp. paratuberculosis/imunologia , Paratuberculose/imunologia , Coelhos , Proteínas Recombinantes/imunologia
7.
Transbound Emerg Dis ; 64(6): 1991-1999, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28120423

RESUMO

In Vietnam, live bird markets are found in most populated centres, providing the means by which fresh poultry can be purchased by consumers for immediate consumption. Live bird markets are aggregation points for large numbers of poultry, and therefore, it is common for a range of avian influenza viruses to be mixed within live bird markets as a result of different poultry types and species being brought together from different geographical locations. We conducted a cross-sectional study in seven live bird markets in four districts of Thua Thien Hue Province in August and December, 2014. The aims of this study were to (i) document the prevalence of avian influenza in live bird markets (as measured by virus isolation); and (ii) quantify individual bird-, seller- and market-level characteristics that rendered poultry more likely to be positive for avian influenza virus at the time of sale. A questionnaire soliciting details of knowledge, attitude and avian influenza practices was administered to poultry sellers in study markets. At the same time, swabs and faecal samples were collected from individual poultry and submitted for isolation of avian influenza virus. The final data set comprised samples from 1,629 birds from 83 sellers in the seven live bird markets. A total of 113 birds were positive for virus isolation; a prevalence of 6.9 (95% CI 5.8-8.3) avian influenza virus-positive birds per 100 birds submitted for sale. After adjusting for clustering at the market and individual seller levels, none of the explanatory variables solicited in the questionnaire were significantly associated with avian influenza virus isolation positivity. The proportions of variance at the individual market, seller and individual bird levels were 6%, 48% and 46%, respectively. We conclude that the emphasis of avian influenza control efforts in Vietnam should be at the individual seller level as opposed to the market level.


Assuntos
Galinhas , Patos , Conhecimentos, Atitudes e Prática em Saúde , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Animais , Comércio , Estudos Transversais , Fezes/virologia , Feminino , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/virologia , Masculino , Doenças das Aves Domésticas/virologia , Prevalência , Vietnã/epidemiologia
8.
Virus Res ; 116(1-2): 78-84, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16216377

RESUMO

Cytopathogenic (cp) bovine viral diarrhea virus (BVDV) strain KS86-1 cp was isolated from a cow persistently infected with non-cytopathogenic (ncp) BVDV strain KS86-ncp after development of mucosal disease by superinfection with cp BVDV strain Nose. cp BVDV strains 799cp and 839cp were also isolated from independent cattle that developed mucosal disease by superinfection with cp BVDV KS86-1cp. In the present study, genetic analysis revealed that the genes of cp BVDV strains 799cp and 839cp were chimeras between the genes of the persisting ncp BVDVs and that of superinfecting KS86-1cp. The genetic recombination that generates 799cp occurred between the identical points in the N(pro) gene region, whereas genetic recombination that generates 839cp occurred between different points in the N(pro) gene region. Both 799cp and 839cp were inherited Jiv gene of KS86-1cp strain and envelope protein genes of the persisting viruses. In addition, neutralization test disclosed that antigenicities of 799cp, 839cp, and KS86-1cp were also similar to each persisting virus. These findings indicate that exogenous cp BVDV containing insertion of Jiv gene in the 5 terminal region can induce genetic recombination with the original ncp BVDV at different points in the N(pro) gene region, and those viruses have high potential to change those antigenicities and pathogenicities by RNA recombination.


Assuntos
Antígenos Virais/genética , Vírus da Diarreia Viral Bovina/imunologia , Vírus da Diarreia Viral Bovina/patogenicidade , Recombinação Genética , Proteínas Virais/genética , Animais , Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Antígenos Virais/fisiologia , Bovinos , Células Cultivadas , Reações Cruzadas , Vírus da Diarreia Viral Bovina/genética , Vírus da Diarreia Viral Bovina/isolamento & purificação , Genoma Viral , Dados de Sequência Molecular , Testes de Neutralização , Técnicas de Amplificação de Ácido Nucleico , RNA Viral/genética , Análise de Sequência de DNA , Proteínas do Envelope Viral/genética , Proteínas Virais/imunologia , Proteínas Virais/fisiologia
9.
J Virol Methods ; 138(1-2): 140-6, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17046073

RESUMO

An immunochromatographic test was developed for rapid diagnosis of bovine viral diarrhea virus (BVDV) infections using monoclonal antibodies against the nonstructural protein, NS3, of the virus. The kit detected specifically the NS3 of various BVDV strains. Using the kit, leukocyte extracts of cattle infected persistently with BVDV were found positive while those of healthy cattle were negative. The sensitivity and specificity of this kit in compared with virus isolation were 100% and 97.2%, respectively. Furthermore, the test also gave positive results for calves infected acutely with BVDV in experimental infection. The BVDV antigen was detected in 1 ml of blood using a relatively simple procedure. This test kit should be useful for rapid diagnosis of BVD.


Assuntos
Antígenos Virais/análise , Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Cromatografia de Afinidade/métodos , Vírus da Diarreia Viral Bovina/imunologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Peptídeo Hidrolases/análise , RNA Helicases/análise , Proteínas não Estruturais Virais/análise , Animais , Sangue/virologia , Bovinos , Leucócitos/virologia , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade , Cultura de Vírus
10.
Dev Biol (Basel) ; 124: 69-72, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16447496

RESUMO

To prepare for the emergence of pandemic influenza in birds and mammals including humans, we have carried out global surveillance of avian influenza. Influenza A viruses of 48 combinations of 15 HA and 9 NA subtypes out of 135 theoretical combinations have been isolated from faecal samples of ducks in Alaska, Siberia, Mongolia, Taiwan, China and Japan. So far, viruses of 73 other combinations have been generated by genetic reassortment in chicken embryos. Thus, avian influenza viruses of 121 combinations of HA and NA subtypes have been stocked for use in vaccine and diagnosis. Their pathogenicity, antigenicity, genetic information, and yield in chicken embryo have been analysed and registered in the database.


Assuntos
Surtos de Doenças/veterinária , Patos/virologia , Saúde Global , Vírus da Influenza A/imunologia , Vacinas contra Influenza/genética , Influenza Aviária/epidemiologia , Alaska/epidemiologia , Animais , Ásia/epidemiologia , Surtos de Doenças/prevenção & controle , Fezes/virologia , Biblioteca Genômica , Humanos , Vírus da Influenza A/genética , Especificidade da Espécie
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