Serum and potassium deprivation-induced neuronal death on the primary culture of rat cerebellar granule neurons is being widely used as an in vitro model of neurodegeneration and neuronal apoptosis. In our experiments, serum and potassium deprivation for 12 h induced neuronal death in approximately 20% of cerebellar granule neurons as demonstrated by Trypan Blue assay. Neuronal death was accomp...

The transient potassium current (I(A)) plays an important role in shaping the firing properties of pyloric neurons in the stomatogastric ganglion (STG) of the spiny lobster, Panulirus interruptus. The shal gene encodes I(A) in pyloric neurons. However, when we over-expressed the lobster Shal protein by shal RNA injection into the pyloric dilator (PD) neuron, the increased I(A) had somewhat diff...

BACKGROUND Patients with chronic iron overload may develop a cardiomyopathy manifested by ventricular arrhythmias and heart failure. We hypothesized that iron-loaded cardiomyocytes may have abnormal excitability. METHODS AND RESULTS We examined a new model of human iron overload, the Mongolian gerbil given repeated injections of iron dextran. In ventricular myocytes, we measured iron concentr...

OBJECTIVES Hypertrophy has been shown to be associated with arrhythmias which can be caused by abnormal remodeling of the Kv4-family of transient potassium channels. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins) have recently been shown to exert pleiotropic protective effects in cardiovascular diseases, including anti-arrhythmias. It is hypothesized that remodeling of ...

L-type, voltage-dependent calcium (Ca(2+)) channels, ryanodine-sensitive Ca(2+) release (RyR) channels, and large-conductance Ca(2+)-activated potassium (K(Ca)) channels comprise a functional unit that regulates smooth muscle contractility. Here, we investigated whether genetic ablation of caveolin-1 (cav-1), a caveolae protein, alters Ca(2+) spark to K(Ca) channel coupling and Ca(2+) spark reg...

Cheng, Xiaoyang, and Jonathan H. Jaggar. Genetic ablation of caveolin-1 modifies Ca spark coupling in murine arterial smooth muscle cells. Am J Physiol Heart Circ Physiol 290: H2309–H2319, 2006. First published January 20, 2006; doi:10.1152/ajpheart.01226.2005.—Ltype, voltage-dependent calcium (Ca ) channels, ryanodine-sensitive Ca release (RyR) channels, and large-conductance Ca activated pota...

Characterization of outward currents in neurons of the avian nucleus magnocellularis. J. Neurophysiol. 80: 2824-2835, 1998. Neurons of the nucleus magnocellularis (NM) preserve the timing of auditory signals through the convergence of a variety of voltage- and ligand-gated ion channels. To understand better how these channels interact, we have characterized the kinetics, voltage sensitivity, an...

Hyperkalemia generally is attributable to cell shifts or abnormal renal potassium excretion. Cell shifts account for transient increases in serum potassium levels, whereas sustained hyperkalemia generally is caused by decreased renal potassium excretion. Impaired renal potassium excretion can be caused by a primary decrease in distal sodium delivery, a primary decrease in mineralocorticoid leve...

2,5-Di-(tert-butyl)-1,4-benzohydroquinone (TBQ) is a reversible inhibitor of SERCA, potentially making it a useful tool to study the effects of SERCA inhibition in cardiac cells. However, it is unknown if TBQ also has effects on other components of ventricular Ca handling. The aim of these experiments was to characterise the effects of TBQ on Ca handling in rat ventricular myocytes and assess i...

This paper presents a new single-wire autonomous current-share paralleling of current-mode-controlled dc power supplies. The proposed control scheme makes use of the nature of fast response of the inner current loop and the share bus injected signal to improve the response of the power supplies. It reduces the unbalance of current distribution during the transient state and avoids the fault ala...