Navegando por Palavras-chave "Synaptic transmission"
Agora exibindo 1 - 5 de 5
Resultados por página
Opções de Ordenação
- ItemAcesso aberto (Open Access)Estudos da competição entre laminina e ollgômeros Aβ pela ligação à PrPc e seus efeitos no ritmo circadiano(Universidade Federal de São Paulo (UNIFESP), 2017-05-30) Luz, Marcio Henrique Mello da [UNIFESP]; Lee, Kil Sun [UNIFESP]; http://lattes.cnpq.br/7705881286363327; http://lattes.cnpq.br/7724620775199307; Universidade Federal de São Paulo (UNIFESP)Interaction between PrPC and Laminin (LN) promotes neuritogenesis via ERK1/2, while the interaction between PrPC and amyloid-beta oligomer (oAβ) triggers synaptic dysfunction via Fyn kinase, but both complexes use mGluR1 as co-receptor. The involvement of PrPC in these opposite functions suggests that PrPC-mGluR1 acts as a key complex in the regulation of synaptic activity. To better understand how this complex works, we evaluated the interference of oAβ on LN binding to PrPC. We also verified levels of these molecules in different circadian periods and after sleep deprivation (SD), as the synaptic activity oscillates along the sleep-wake cycle. Our results showed that the addition of oAβ reduced LN-PrPC binding, suggesting that these ligands can compete with each other. Regarding the expression levels, we observed a reduction of PrPC in sleep deprived animals, independent of circadian period. mGluR1 levels were increased during the activity period in control animals (CTa) compared to the rest period (CTr), however this variation was attenuated with SD. These results indicate that the signaling triggered by PrPC-mGluR1 might undergo circadian regulation through the alteration of mGluR1 levels, and that SD might impair this regulation. Moreover, the levels of amyloid-beta peptides (pAβ) were increased by SD in rest period (SDr) when compared with CTr group. This increase correlated with hyperphosphorylation of SRC kinases in SDr group and might have contributed to a higher deviation in NMDAR phosphorylation of the same group. Total NMDAR levels in CTr and CTa showed the same profile of mGluR1. Laminin levels did not varied between groups, however ERK1/2 phosphorylation presented subtle decrease in CTa group compared to CTr group, which was not observed in SD groups. These results suggest that ERK1/2 and NMDAR tend to function in an opposite way during the activity time in control animals. However, SD seems to attenuate the variation of ERK/12 activity and hyperactivate SRC kinases leading to a NMDAR deregulation.
- ItemSomente MetadadadosEvaluation of -Aminocarboxylic Acid Derivatives in Hippocampal Excitatory Synaptic Transmission(Wiley-V C H Verlag Gmbh, 2017) Oliveira, Daniela R.; Luchez, Cibele V. [UNIFESP]; Bortolotto, Zuner A.; Fernandes, Joao P. S. [UNIFESP]-Aminocarboxylic acid derivatives (LINS04 series) were screened with the aim to explore their potential functional role in excitatory synaptic transmission in the central nervous system. We used field recordings in rat hippocampal slices to investigate th
- ItemEmbargoFarmacologia da musculatura lisa de filhotes de ratas de mães tratadas com álcool etílico na gravidez e aleitamento.(Universidade Federal de São Paulo (UNIFESP), 2008-11-26) Verde, Luciana Ferreira [UNIFESP]; Jurkiewicz, Aron [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Em mães etilistas, a ingestão de álcool durante o período da prenhez e aleitamento produziu: 1. Menor ingestão de calorias provenientes da ração em relação ao consumo das mães controles. 2. Menor ingestão de calorias, mesmo consumindo duas fontes de energias diferentes (ração e álcool). 3. O consumo alimentar das mães etilistas foi afetado pelo consumo de etanol, demonstrando que a ingestão de etanol afetou o estado nutricional das mães, sugerindo que a absorção de nutrientes e a metabolização estejam alterados. 4. Baixo ganho de peso durante a prenhez e diminuição de peso corporal durante o aleitamento. 5. Grande variação na concentração sanguínea de álcool nas mães etilistas , que pode ser explicada pelo baixo consumo alimentar, tempo de exposição ao álcool, dose consumida. 6. Maior número de abortos, morte das parturientes, filhotes natimortos e diminuição no tamanho da ninhada. 7. Ausência de atraso no parto de todos grupos estudados. Em filhotes machos e fêmeas de mães etilistas, a ingestão de álcool durante o período da prenhez e aleitamento produziu: 8. Diminuição na Taxa de desmame (T.D.) e Aumento da Taxa de mortalidade (T.M.) Associado ao alto índice de mortalidade nos filhotes: canibalismo das mães (logo após o nascimento ou durante o desmame), altos níveis de álcool no sangue, baixo peso corporal até o 45º dia de vida de filhotes machos e fêmeas. 9. Diminuição no peso de órgãos (ovário, fundus e coração, ddr e testículos), de filhotes machos e fêmeas 10. Altos níveis de álcool no sangue dos filhotes machos e fêmeas, que também está associado ao alto índice de mortes dos filhotes e também explica o porque muitos deles não sobrevivem até o desmame, ou morrem logo após o parto. 11. Embora o baixo peso nos filhotes tenha persistido durante toda a evolução corporal dos filhotes, há uma tendência a recuperação, conforme foi vista pelo aumento de peso quando o etanol foi suspenso com o desmame. Contudo, o tempo de interrupção (28-45° dia de vida dos filhotes) não foi suficiente para a recuperação do peso dos filhotes. 12. Diminuição da reatividade do DDR quando induzida por drogas (CaCl2, KCl, noradrenalina) ou por estímulo elétrico transmurral, mostrando que o componente fásico parece estar afetado. 13. Alteração de eventos pré e pós-sinápticos dos ductos deferentes de filhotes, sendo que os eventos pós-sinápticos parecem ser mais afetados, já que a concentração intracelular do íon cálcio pode estar relacionada com alterações da mobilização celular do cálcio. 14. Diminuição da reatividade do DDR, corroborando que os sistemas receptores deste órgão, pelo menos o adrenérgico, foram susceptíveis às perturbações. causadas pelo tratamento com álcool.
- ItemAcesso aberto (Open Access)Influência da aprendizagem e da manipulação do sistema colinérgico muscarínico na sensibilização ao efeito estimulante do etanol(Universidade Federal de São Paulo (UNIFESP), 2011-02-21) Takahashi, Shirley [UNIFESP]; Souza-Formigoni, Maria Lucia Oliveira de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Several authors suggest that behavioral sensitization, characterized as psychomotor activity increase in response to psychoactive drugs repeated administration, seems to play a fundamental role in the development of abuse and dependence, increasing the reinforcement property of these substances. Animals that develop sensitization to ethanol differ regarding the binding to some neurotransmitter receptors and also differ regarding the response to the administration of agonists and antagonists of these receptors. Behavioral sensitization is a complex phenomenon that involves different factors, being affected by environment and learning. To evaluate the influence of learning capacity in the sensitization process, in the present study we compared the performance of two groups of mice that presented different levels of sensitization (high and low) in two different learning tasks (appetitive and aversive). We also evaluated the influence of an amnestic drug (scopolamine) in the development and expression of sensitization. It was observed that mice with different levels of sensitization did not differ regarding their learning capacity after chronic treatment with ethanol, in both tasks. Scopolamine, when administered in the dorsal hippocampus simultaneously with ethanol treatment, did not alter the sensitization development. However, when administered subcutaneously it induced higher levels of locomotor activity in those animals that had already developed high sensitization than in low sensitized mice or in the control group. This phenomenon was not observed when scopolamine was administered directly in the nucleus accumbens. When administered in combination with ethanol, it blocked the sensitization. These data suggest that the cholinergic system acts as a neuromodulator in the sensitization process. However, the cholinergic system seems to act in different ways depending on the level of sensitization developed by the animal.
- ItemSomente MetadadadosThe role of the paratrigeminal nucleus in the pressor response to sciatic nerve stimulation in the rat(Elsevier B.V., 2008-06-01) Caous, Cristofer André [UNIFESP]; Koepp, Janice; Couture, Rejean; Balan, Antonio Claudir [UNIFESP]; Lindsey, Charles Julian [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Inst Israelita Ensino & Pesquisa Albert Einstein; Univ MontrealThe paratrigeminal nucleus (Pa5), an input site for spinal, trigeminal, vagus and glossopharyngeal afferents, is a recognized site for orofacial nociceptive sensory processing. It has efferent connections to brain structures associated with nociception and cardiorespiratory functions. This study aimed at determining the function of the Pa5 on the cardiovascular component of the somatosensory reflex (SSR) to sciatic nerve stimulation (SNS) in paralyzed and artificially-ventilated rats following Pa5 chemical lesions (ibotenic acid), synaptic transmission blockade (CoCl(2)), local anaesthetics (lidocaine) or desensitization of primary afferent fibers (capsaicin). the pressor response to sciatic nerve stimulation at 0.6 mA and 20 Hz (14 +/- 1 mm Hg) was strongly attenuated by contra-(-80%) or bilateral (-50%) paratrigeminal nucleus lesions. Ipsilateral Pa5 lesions only attenuated the response to 0.1 mA, 20 Hz SNS (-55%). Cobalt chloride or lidocaine injected in the contralateral paratrigeminal nucleus also attenuated the SSR. in capsaicin-treated animals, the pressor responses to 0.1 mA were abolished, whereas the responses to SNS at 0.6 mA were increased from 65 to 100% depending on the stimulus frequency. the paratrigeminal nucleus receives both, excitatory and inhibitory components; the later apparently involving capsaicin-sensitive fiber inputs mostly to the ipsilateral site whereas the capsaicin insensitive excitatory components that respond to high or low frequency stimulation, respectively, target the contralateral and ipsilateral sites. Thus, the paratrigeminal nucleus mediates excitatory and inhibitory components of the somatosensory reflex, representing a primary synapse site in the brain for nociceptive inputs from the sciatic innervation field. (C) 2008 Published by Elsevier B.V.