Light-Enhanced Startle as an Experimental Model of Withdrawal

Nicotine is extremely addictive, and the negative effects of withdrawal, such as increased anxiety, contribute to relapse. Nicotine produces significant changes in the extended amygdala, the brain regions responsible for regulating anxiety. Light-Enhanced Startle is an established method for assessing anxiety in animal models and is sensitive to drug manipulations. This thesis had two goals, Experiment 1 asked: can LES be used to investigate the anxiety of extended nicotine withdrawal following chronic nicotine administration in rats? We hypothesized that exposing rats to chronic nicotine would result in elevated LES during spontaneous withdrawal as compared to controls, and that this elevation in LES would decrease as withdrawal progressed. Adult Sprague-Dawley rats were given .40 mg/kg nicotine twice daily for 14 days, and were then tested in LES on withdrawal days 1, 3, and 5. Animals showed significantly increased anxiety on withdrawal day 1, and exhibited a pattern of decreasing but elevated LES on withdrawal days 3 and 5 consistent with our predictions. Experiment 2 built on Experiment 1, and asked: what effect will brief nicotine pre-exposure have on the anxiety of withdrawal following later administration? We hypothesized that briefly exposing animals to nicotine, followed by abstinence and then chronic exposure, would potentiate the anxiogenic effects of withdrawal, resulting in even further elevated LES during withdrawal. Adult rats were given 4 days of .40 mg/kg nicotine, followed by 10 days of abstinence, and then chronic nicotine and LES as described above. Surprisingly, animals in Experiment 2 displayed a general decrease in LES, indicating that nicotine pre-exposure has an anxiolytic effect during later withdrawal. These findings demonstrate that nicotine pre-exposure has a significant impact on how the brain responds to later nicotine, and this could be caused by a unique pattern of nAChR desensitization and upregulation resulting from pre-exposure

Aquí vienen las novias: leyendo las pinturas neolíticas de Uan Derbuaen (Tasili n’Ajer, Argelia)

The Tassil-n-Ajjer mountain range is well known for its phenomenal richness in rock-shelters and cave paintings. Generations of researchers have surveyed, mapped, drafted and discussed different facets of these Tassili paintings. The diversity and versatility of the paintings traditions of the Tassili make difficult any attempt at straightforward generalization, whether stylistic or thematic. Each painting’s station appears to be unique and conveys its own suggestions that have to be studied extensively and systematically. In the approach outlined in this paper –the iconographic approach–, paintings are viewed as complex sets of ‘artifacts’ arranged by the creative minds of the actual artists. How did these artists practice their crafts? What iconic elements did they choose to represent and why? How and why are these selected elements arranged and combined? These are some of the questions addressed in this paper. The new readings of the Uan Derbuaen paintings allow to suggest a staging and grand representation of matrimonial arrangements, the final travel of the brides.La cordillera montañosa del Tasili n’Ajer es bien conocida por su fenomenal riqueza en abrigos y cuevas pintados. Generaciones de investigadores han prospectado, cartografiado, dibujado y discutido diferentes facetas de estas pinturas del Tasili. La diversidad y versatilidad de las tradiciones pictóricas del Tasili hace difícil cualquier intento de generalización directa ya sea estilística o temática. Cada estación pintada parece ser única y expresiva de sugerencias propias que deben ser estudiadas extensa y sistemáticamente. En el enfoque esbozado en este artículo, un enfoque iconográfico, las pinturas son consideradas como series complejas de “artefactos” organizados por las mentes creativas de los artistas reales. ¿Cómo desarrollaban sus habilidades esos artistas? ¿Qué elementos icónicos escogieron para la representación y por qué? ¿Cómo y por qué esos elementos seleccionados se organizaron y combinaron? La nueva lectura de las pinturas de Uan Derbuaen permite sugerir una puesta en escena y una gran representación de los arreglos matrimoniales, el viaje final de las novias

Composition of Rambutan Seeds

The seeds of three rambutan clones (R4, R 7 and R169) were analysed. Proximate analysis of the seeds showed that they contained 11.9-14.1% protein, 37.1-38.9% crude fat (peroleum ether extract), 2.8-6.6% crude fibre and 2.6-2.9% ash on a dry weight basis. The seeds contained 34.1-34.6% moisture. The amino acid profile of the seed protein showed that the protein was of good quality. The major fatty acids in rambutan seed fat were C16:0 (4.36-4.86%); C18:0 (5.93-7.49%); C18:1 (37.91-40.15%); C20:0 (36.14-36.77%) and C20:1 (6.92-7.27%)