We investigated how spontaneous activity is generated in developing, hyperexcitable networks. We focused our study on the embryonic chick spinal cord, a preparation that exhibits rhythmic discharge on multiple timescales: slow episodes (lasting minutes) and faster intraepisode cycling (approximately 1 Hz frequency). For this purpose, we developed a mean field model of a recurrent network with s...

Dietary potassium deficiency activates thiazide-sensitive sodium chloride cotransport along the distal nephron. This may explain, in part, the hypertension and cardiovascular mortality observed in individuals who consume a low-potassium diet. Recent data suggest that plasma potassium affects the distal nephron directly by influencing intracellular chloride, an inhibitor of the with-no-lysine ki...

Cuppoletti, John, Danuta H. Malinowska, Kirti P. Tewari, Qiu-ju Li, Ann M. Sherry, Myra L. Patchen, and Ryuji Ueno. SPI-0211 activates T84 cell chloride transport and recombinant human ClC-2 chloride currents. Am J Physiol Cell Physiol 287: C1173– C1183, 2004. First published June 22, 2004; doi:10.1152/ajpcell. 00528.2003.—The purpose of this study was to determine the mechanism of action of SP...

Stimulation with heavy metals is known to induce calcium (Ca(2+)) mobilization in many cell types. Interference with the measurement of intracellular Ca(2+) concentration by the heavy metals in cells loaded with Ca(2+) indicator fura-2 is an ongoing problem. In this study, we analyzed the effect of heavy metals on the fura-2 fluorescence ratio in human SH-SY5Y neuroblastoma cells by using TPEN,...

The rare earth metals cerium, lanthanum, and neodymium each were evaluated in an in vitro cytotoxicity assay system using adult, male Sprague-Dawley rat pulmonary alveolar macrophages. Both the soluble chloride form of these metals and their insoluble metal oxides were studied. For comparison purposes, the cytotoxicities of cadmium chloride and cadmium oxide were also quantified in this test sy...

Three polyphenols were isolated and purified from sugar beet molasses by ultrasonic-aid extraction and various chromatographic techniques, and their structures were elucidated by spectral analysis. Cytotoxicity and the molecular mechanism were measured by methyl thiazolyl tetrazolium (MTT) assay, flow cytometry, caspase-3 activity assay and Western blot assay. The results showed that gallic aci...

Background: Cell therapy of many neurodegenerative diseases using bone marrow stromal cells (BMSC) requires the differentiation of BMSC into neuronal subtype. However, the transdifferentiation of BMSC into GABAergic phenotype requires more investigation. Methods: In this study, BMSC of adult female rats were pre-induced into neuroblast-like cells using 1 mM β-mercaptoethanol (βME) and 10 M re...

The purpose of this study was to determine the mechanism of action of SPI-0211 (lubiprostone), a novel bicyclic fatty acid in development for the treatment of bowel dysfunction. Adult rabbit intestine was shown to contain mRNA for ClC-2 using RT-PCR, Northern blot analysis, and in situ hybridization. T84 cells grown to confluence on permeable supports were shown to express ClC-2 channel protein...