Involvement of ceramide in ethanol-induced apoptotic neurodegeneration in the neonatal mouse brain.

Acute administration of ethanol to 7-day-old mice is known to cause robust apoptotic neurodegeneration in the brain. Our previous studies have shown that such ethanol-induced neurodegeneration is accompanied by increases in lipids, including ceramide, triglyceride (TG), cholesterol ester (ChE), and N-acylphosphatidylethanolamine (NAPE) in the brain. In this study, the effects of ethanol on lipid profiles as well as caspase 3 activation were examined in the cortex, hippocampus, cerebellum, and inferior colliculus of the postnatal day 7 mouse brain. We found that the cortex, hippocampus, and inferior colliculus, which showed substantial caspase 3 activation by ethanol, manifested significant elevations in ceramide, TG, and NAPE. In contrast, the cerebellum, with the least caspase 3 activation, failed to show significant changes in ceramide and TG, and exhibits much smaller increases in NAPE than other brain regions. Ethanol-induced increases in ChE were observed in all brain regions tested. Inhibitors of serine palmitoyltransferase effectively blocked ethanol-induced caspase 3 activation as well as elevations in ceramide, ChE, and NAPE. Immunohistochemical studies indicated that the expression of serine palmitoyltransferase was mainly localized in neurons and was enhanced in activated caspase 3-positive neurons generated by ethanol. These results indicate that de novo ceramide synthesis has a vital role in ethanol-induced apoptotic neurodegeneration in the developing brain.

Assessment of antidiarrhoeal activity of Desmostachya bipinnata L. (Poaceae) root extracts / Evaluación de la actividad de antidiarreica de extractos de la raíz de Desmostachya bipinnata L. (Poaceae)

Desmostachya bipinnata root has been used in the Indian traditional system of medicine for treatment of diarrhoea and dysentery. The antidiarrhoeal effect of both alcoholic and aqueous extracts of the roots of Desmostachya bipinnata were studied in rats against castor oil induced diarrhoea and charcoal meal test at the doses of 200 and 400 mg/kg body weight. The alcoholic extract and to a lesser extent aqueous extract significantly reduced the weight of the faces and decreased the propulsion of charcoal meal through the gastrointestinal tract. The phytochemical screening of the extracts showed the presence of alkaloids, glycosides, flavonoids, tannins, phytosterol, terpenoids, polyphenolics, protein and carbohydrates. These results may support the fact that this plant is used traditionally to cure diarrhoea.

La raíz de Desmostachya bipinnata ha sido utilizada en el sistema tradicional de medicina Hindú para el tratamiento de diarrea y disentería. El efecto antidiarreico de los extractos alcohólicos y acuosos de los extractos de la raíz de Desmostachya bipinnata fueron estudiados en ratas, utilizando la diarrea inducida por aceite de castor y el ensayo de la prueba por carbón en dosis de 200 y 400 mg/kg de peso corporal. El extracto alcohólico y en menor grado, el extracto acuoso, redujeron significativamente la propulsión de carbón a través del tracto gastrointestinal. El análisis de los extractos mostrarón la presencia de alcaloides, glicósidos, flavonoides, taninos, fitoesterol, terpenoides, polifenoles, proteínas y carbohidratos. Estos resultados pueden apoyar el hecho de que esta planta sea usada tradicionalmente para curar la diarrea.

Perceptual learning of non-native speech contrast and functioning of the olivocochlear bundle.

The purpose of this study was to investigate the relationship between perceptual learning of non-native speech sounds and strength of feedback in the medial olivocochlear bundle (MOCB). Discrimination abilities of non-native speech sounds (Malayalam) from its native counterparts (Hindi) were monitored during 12 days of training. Contralateral inhibition of otoacoustic emissions were measured on the first and twelfth day of training. Results suggested that training significantly improved reaction time and accuracy of identification of non-native speech sounds. There was a significant positive correlation between the slope (linear) of identification scores and change in distortion product otoacoustic emission inhibition at 3000 Hz. Findings suggest that during perceptual learning feedback from the MOCB may fine tune the brain stem and/or cochlea. However, such a change, isolated to a narrow frequency region, represents a limited effect and needs further exploration to confirm and/or extend any generalization of findings.