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Papel dos receptores GABA-benzodiazepínicos da matéria cinzenta periaquedutal na modulação da ansiedade em camundongos ingênuos e reexpostos ao labirinto em cruz elevado
(Universidade Federal de São Carlos, 2006-11-10) Reis, Luciana Maria dos; Souza, Azair Liane Matos do Canto de; https://lattes.cnpq.br/2352004564367849; https://lattes.cnpq.br/2993264661694458
It is well known that the previous experience to the elevated plus-maze (EPM) increases the avoidance of rodents to the open arms and impairs the anxiolytic-like effect of benzodiazepines in a subsequent exposure to the EPM, a phenomenon known as "one trial tolerance" (OTT). This study investigated the effects of intra-periaqueductal gray matter (PAG) infusions of midazolam (MDZ) in EPM-naïve and EPM-experienced mice. The antiaversive effects of MDZ were also evaluated after prior injection of flumazenil, a benzodiazepine receptor antagonist, into to same midbrain site. Test videotapes were scored for conventional measures of anxiety (% open arm entries and % open arm time) and locomotor activity (frequency of closed arm entries), as well as a range of ethological measures related to risk assessment (e.g. stretch attend postures; head dips, etc). In EPMnaïve mice, intra-PAG infusions of MDZ increased % open arm entries (2.26 nmol) and % open arm time (2.26 and 30 nmol). These effects were observed in the absence of significant changes in locomotor activity, indicating a selective anxiolytic-like effect of MDZ. The antiaversive effects of MDZ were completely blocked by prior injection of flumazenil (16 nmol) into the same midbrain site, and did not alter any behavioral measures per se. In EPMexperienced mice, intra-PAG infusion of MDZ did not modify any behavioral measures. Taken together, present results demonstrates that GABA-benzodiazepine receptor complex located within the PAG plays a role on anxiety modulation in EPM-naïve mice as well as indicates its involvement in the OTT phenomenon.
Diversidade de peixes residentes em cabeceiras de rios. Uma abordagem cromossômica em três diferentes biomas aquáticos da Região Sul do Brasil
(Universidade Federal de São Carlos, 2006-11-10) Vicari, Marcelo Ricardo; Bertollo, Luiz Antonio Carlos; https://lattes.cnpq.br/9824170107078686
This study presented cytogenetic analysis of small fishes species collected in the headwaters of Jaguariaíva, Ribeira and, Tibagi rivers. Some of these species have had a comparative cytogenetic population analysis among different basins, while in the others were observed inherent specific problems only in one population. In this work we boarded cytogenetic, cytotoxonomy, biogeographic and evolutive biology aspects of these populations: Corydoras paleatus, Corydoras ehrhardti, Apareiodon sp., Geophagus brasiliensis, Cichlasoma facetum, Astyanax scabripinnis species complex, Astyanax janeiroensis, and Characidium sp. cf. C. gomesi. Here we discussed and presented (a) the sympatric occurrence of C. paleatus and C. ehrhardti from Dourada lagoon, Tibagi basin; (b) a ZZ/ZW sex chromosome system in an undescribed species of the genus Apareiodon in the Verde river, Tibagi basin (c) the karyotypic conservadorism visualized in species and populations of Perciformes, G. brasiliensis and C. facetum, in the Jaguariaíva, Ribeira and Tibagi basins, showing the dispersion of fish species hypotheses among these basins; (d) a comparative cytogenetic analysis of A. scabripinnis species complex, among Jaguariaíva, Ribeira, and Tibagi basins, all of them shared karyotypes with 2n=50 chromosomes but minors differences among them were observed, and we also showed a sympatric cytotype with 2n=48 chromosomes only in the Jaguariaíva basin; (e) the composition, location and nature of heterochromatic sites present in the A. janeiroensis karyotype of Ribeira basin and; (f) a possible sinapomorphic condition in the Characidium species with heteromorphic sex chromosome system. We also discussed the possible faunes interchange in the headwaters regions of Ribeira de Iguape and Tibagi rivers in the Ponta Grossa arc region, beside to the supposed endemic ictiofaune of Jaguariaíva basin. Thus, this study associated cytogenetic data, biogeographic aspects, and evolutive biology of fishes species located in the headwaters of three Paraná State rivers.