Distribution and morphology of the ampullary organs of the estuarine long-tailed catfish, Euristhmus lepturus (Plotosidae, Siluriformes)

Ampullary organs of Euristhmus lepturus occur in high densities along the head and in four parallel pathways along the trunk of the body. Large ampullary pores (125–130 μm) are easily distinguishable from other sensory epithelial pores due to the differences in size and the presence of a collar-like structure. Simple, singular ampullary organs of the head region consist of an ampullary pore connected to a long canal with a diameter of 115–175 μm before terminating as a simple ampulla with an external diameter of 390–480 μm. The ampullary canal is composed of 1–2 layers of flattened squamous epithelial cells, the basement membrane and an interlocking collagen sheath. The innermost cells lining the canal wall are adjoined via tight junctions and numerous desmosomes, as are those of the receptor and supportive cells. Canal wall tissue gives rise to a sensory epithelium containing between 242 and 285 total receptor cells, with an average diameter of 11.7 ± 5.3 μm, intermixed with medially nucleated supportive cells. Each receptor cell (21.38 ± 4.41 μm, height) has an apically positioned nucleus and a luminal surface covered with numerous microvilli. Neural terminals abut the basal region of receptor cells opposite multiple presynaptic bodies and dense mitochondria. Supportive cells extend from the ampullary lumen to the basement membrane, which is adjacent to the complex system of collagen fibres

Nutrition and Central Nervous System

Clinical studies have revealed that depression is accompanied by impaired brain function and cognitive performances or neurodegenerative processes. Moreover, accumulation of oxidative damage has been implicated in aging and various neurological disorders. This chapter aims to integrate the current knowledge on the relation between brain and diverse alterations in nutrition. The mammalian brain is a lipid-rich organ, where lipids content in gray matter is 36–40% lipid. However, the regulation of cholesterol transport from astrocytes to neurons still remains unclear, among other things. In addition to that, micronutrient status can affect cognitive function at all ages. Vitamin deficiency could influence memory function, and might contribute to cognitive impairment and dementia. Deficiency of vitamin A, folate, vitamins B6, B12, and minerals such as Fe and Zn are associated with prevalence of depressive symptoms according to several epidemiological studies. Experimental evidence suggests that resveratrol, vitamins A, C, E, D and folate may block oxidative stress and promote clearance of Aβ peptides. An adequate intake of fruit, nuts, vegetables, cereals, legumes, or fish can prevent the depletion. High dietary intake of saturated fat and low intake of vegetables may be associated with increased risk of Alzheimer’s disease. Supplementation of diets with omega-3 has been shown to have positive effects on cognitive function. The biochemical and molecular mechanism of these alterations of normal brain function has been described. Future studies should also examine how DNA repair deficiency occurs and affects the nervous system, because this could provide a rational basis for therapies in neurodegenerative diseases.Fil: Alvarez, Silvina Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Gomez, Nidia Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Navigatore Fonzo, Lorena Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Sanchez, Emilse Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Gimenez, Maria Sofia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentin