Ca2+ currents in dorsal unpaired median (DUM) neurons isolated from the fifth abdominal ganglion of the cockroach Periplaneta americana were investigated with the whole cell patch-clamp technique. On the basis of kinetic and pharmacological properties, two different Ca2+ currents were separated in these cells: mid/low-voltage-activated (M-LVA) currents and high-voltage-activated (HVA) currents....

OBJECTIVE To determine the effect of changes in autonomic tone induced by phenylephrine infusion on atrial refractoriness and conduction. DESIGN Left and right atrial electrophysiological properties were measured before and after a constant phenylephrine infusion designed to increase sinus cycle length by 25%. SUBJECTS 20 patients, aged 53 (SD 6) years, undergoing electrophysiological study...

Right ventricular cardiac tissue (10-20 mg wet weight) was obtained from anesthetized adult dogs by endomyocardial biopsy. The biopsy could be repeated in one dog every 2 weeks for up to 3 months. Fifty to 200 cardiomyocytes, dispersed with collagenase and trypsin, were collected by centrifugation of the cells with 50% polysucrose-sodium diatrizoate solution (Ficoll-Paque). Single cardiomyocyte...

Background/aim: Isolated cell cultures are widely used to study neuronal properties due to their advantages. Although embryonic animals are preferred for culturing, their morphological or electrophysiological properties may not reflect adult neurons, which may be important in neurodegenerative diseases. This paper aims to develop a method for preparing isolated cell cultures of medial vestibula...

introduction: developmental changes in atrioventricular nodal conduction time and refractoriness have been shown in several studies. prevalence of atrioventricular nodal reentrant tachycardia (avnrt) is clearly age-dependent. the purpose of this study was to determine developmental changes of basic and frequency-dependent electrophysiological properties of the atrioventricular node (av-node) in...

There are between 20 and 30 drugs available for the treatment of seizures but despite this ~30% of the epilepsy population remains unresponsive to treatment. The underlying mechanisms behind drug resistance in temporal lobe epilepsy (TLE) have not been completely identified. The purpose of this study was to determine if distinct types of neuronal firing patterns occurring in human epileptic cor...

Most neurons have large numbers of voltage- and time-dependent currents that contribute to their electrical firing patterns. Because these currents are nonlinear, it can be difficult to determine the role each current plays in determining how a neuron fires. The lateral pyloric (LP) neuron of the stomatogastric ganglion of decapod crustaceans has been studied extensively biophysically. We const...

The forebrains of mammals and birds appear quite different in their gross morphology, making it difficult to identify homologies between them and to assess how far they have diverged in organization. Nevertheless one set of forebrain structures, the basal ganglia, has been successfully compared in mammals and birds. Anatomical, histochemical, and molecular data have identified the avian homolog...

The pulmonary vein contains a myocardial layer extending from the left atrium, which is receiving attention as the source of ectopic electrical activity underlying atrial fibrillation. Electrophysiological and pharmacological analysis of the pulmonary vein myocardium performed in various experimental animal species have revealed characteristics such as presence of intracellular Ca(2+) oscillati...

The present study sought to uncover the emotion regulatory properties of mindfulness by examining its effects-differentiated as a meditative practice, state of mind and dispositional trait-on the late positive potential (LPP), an event-related potentials (ERPs) indexing emotional processing. Results revealed that mindfulness as a meditative practice produced a reduction in the difference betwee...