RESUMEN
It has been suggested that the left medial prefrontal cortex (LmPFC) has an inhibitory role in controlling the right mPFC (RmPFC), thereby reducing the deleterious effects of stressors on emotional states. Here, we investigated the effects on anxiety of bilateral or unilateral injections of NOC-9 [a nitric oxide (NO) donor] and cobalt chloride (CoCl2; a synaptic inhibitor) into the mPFC of mice exposed to the elevated plus-maze (Experiments 1 and 2). The effects of restraint or social defeat on anxiety in undrugged mice were recorded at 5 min or 24 h after exposure to the stress (Experiment 3). Experiment 4 investigated the effects of LmPFC injection of CoCl2 combined with restraint or social defeat on anxiety, which was recorded 24 h later. Although intra-RmPFC NOC-9 produced anxiogenesis, its injection into the LmPFC, or bilaterally, did not change anxiety. Intra-RmPFC or -LmPFC injection of CoCl2 produced anxiolytic- and anxiogenic-like effects, respectively. Both restraint and social defeat produced anxiogenesis at 5 min, but defeated mice did not display anxiety 24 h after the stress. Although intra-LmPFC CoCl2 did not change anxiety, which was recorded 24 h later in non-stressed mice, this synaptic inhibitor produced a clear, anxiogenic-like effect in defeated (but not restrained) mice. These results suggest that (i) nitrergic activation of the RmPFC increases anxiety, which in turn is inhibited by NO production within the LmPFC; (ii) neuronal inhibition of the RmPFC or LmPFC elicits anxiolysis and anxiogenesis, respectively; and (iii) inactivation of the LmPFC results in recrudescence of anxiety induced by social defeat stress.
Asunto(s)
Ansiedad/metabolismo , Lateralidad Funcional/fisiología , Óxido Nítrico/fisiología , Corteza Prefrontal/fisiología , Animales , Ansiolíticos/administración & dosificación , Ansiedad/inducido químicamente , Ansiedad/tratamiento farmacológico , Cobalto/administración & dosificación , Relación Dosis-Respuesta a Droga , Lateralidad Funcional/efectos de los fármacos , Inyecciones Intraventriculares , Masculino , Ratones , Corteza Prefrontal/efectos de los fármacos , Triazenos/administración & dosificaciónRESUMEN
A espécie medicinal Vernonia condensata, vulgarmente conhecida por alumã, pertencente à família Asteraceae, possui propriedades analgésicas e de proteção gástrica. A crescente utilização dessa planta no Nordeste, pelas propriedades terapêuticas, justifica a necessidade de medidas que minimizem o impacto de sua exploração nas reservas naturais. O objetivo desse trabalho foi multiplicar in vitro plantas de alumã sob diferentes concentrações de BAP e aclimatá-las. Gemas axilares foram desinfestadas em solução de álcool etílico 70 por cento, durante 2 minutos e em solução de hipoclorito de sódio (2 por cento de cloro ativo) na concentração de 3:1, durante 15 minutos, seguido de três lavagens em água destilada estéril. Os tratamentos para multiplicação consistiram em doses de BAP (0,0; 1,0; 2,0; 3,0; 4,0 e 5,0 mg L-1) em meio MS semi-sólido. O delineamento experimental foi o inteiramente casualizado, com 5 repetições, contendo 10 gemas por repetição. Após 30 dias de cultivo observou-se maior taxa de explantes responsivos, 84 por cento na concentração de 1,0 mg L-1 de BAP, com produção de 4,0 brotos/explante. Nos tratamentos 3,0; 4,0 e 5,0 mg L-1 ocorreu hiperhidricidade nas folhas. As microplantas de alumã provenientes da metodologia utilizada neste trabalho alcançaram 100 por cento de sobrevivência na aclimatação.
The medicinal species Vernonia condensata, commonly known as "alumã", belongs to the family Asteraceae and has analgesic and gastric protective properties. The increasing use of this plant in the Northeast of Brazil due to its therapeutic properties justifies the need of measures to minimize the impact of its exploitation in natural reserves. The aim of this study was to multiply, in vitro, "alumã" plants under different BAP levels, acclimating them. Axillary buds were sterilized in 70 percent (v/v) alcohol solution for 2 minutes and in 75 percent sodium hypochlorite solution (2 percent active chlorine) at 3:1 concentration for 15 minutes, followed by three washings in sterile distilled water. Multiplication treatments consisted of different BAP levels (0.0; 1.0; 2.0; 3.0; 4.0 and 5.0 mg L-1) in semi-solid MS medium. The experimental design was completely randomized, with 5 replicates and 10 buds per replicate. After 30 days of cultivation, the highest rate of responsive explants was obtained: 84 percent at 1.0 mg L-1 BAP, producing 4.0 sprouts/explant. In the treatments 3.0, 4.0 and 5.0 mg L-1, there were vitrified leaves. The "alumã" microplants used in this study had 100 percent survival in acclimation.
Asunto(s)
Técnicas In Vitro/métodos , Vernonia/clasificación , Aclimatación , Plantas Medicinales/clasificación , Biotecnología/instrumentación , Técnicas de Cultivo de Tejidos/métodosRESUMEN
The aim of this work is to study the effect of the platinum content (0-1.8 wt % Pt) on the microstructure of an alumina-pillared clay. For this purpose, the nitrogen physisorption data at -196 degrees C, the micropore size distributions of the supported platinum catalysts, and the hydrogen chemisorption results at 30 degrees C have been analyzed and compared. The preparation of the catalysts has modified the textural properties of the Al-pillared clay support, giving rise to a loss of surface area and micropore volume. After reduction at 420 degrees C, the presence of dispersed metallic platinum with mean crystallite size in the 22-55 A range has been found by hydrogen adsorption. Comparison of all results reveals that the platinum species block the micropore entrances by steric hindrance to nitrogen access as the platinum content increases.