In the first 4 hours after occlusion of the anterior septal coronary artery, 18 dogs developed bundle branch block, heart block, or both. The hearts were then excised, and preparations were dissected to expose the His bundle and the bundle branches, which were superfused with modified Tyrode's solution at 37 degrees C. In the His bundle and the most proximal bundle branches, resting potentials ...

OBJECTIVE The aim of this study was to analyze whether cells with long action potential duration, fast Vmax, and spike-and-dome configuration (M-cells) are present in porcine left ventricular myocardium. METHODS Transmembrane action potentials (n = 505) of the left ventricle were recorded with conventional glass microelectrodes in an epicardial-endocardial direction at 2000 ms basic cycle len...

Understanding the mechanisms that influence the initiation of action potentials in single neurons is an important step in determining the way information is processed by neural networks. Therefore, we have investigated the properties of action potential thresholds for hippocampal neurons using in vivo intracellular recording methods in Sprague-Dawley rats. The use of in vivo recording has the a...

In order to extract neural information, action potentials recorded with cuff electrodes from peripheral nerves were classified into unit activities. The classification was performed based on their waveforms, as it was considered that they were affected by the radius of nerve fiber and the distance between fiber and recording electrode. This study focused on automatic classification method. Acti...

Inhibitory interneurons of the dorsal lateral geniculate nucleus of the thalamus modulate the activity of thalamocortical cells in response to excitatory input through the release of inhibitory neurotransmitter from both axons and dendrites. The exact mechanisms by which release can occur from dendrites are, however, not well understood. Recent experiments using calcium imaging have suggested t...

An updated program for modeling simplified heart geometry and simulation of action potentials propagation is presented. The implemented model allows simulation of geometry changes as well as changes in action potentials amplitude and duration. In propagation simulation real conduction velocities can be considered. Two different pathological situations were simulated using the model. First, only...

A study was made of the change's produced in action potentials of frog ventricular cells by variation in ion concentrations, by administration of NaN3, 2: 4 DNP, NaCN, NalA and N2 which shortened the potentials. The exposure of the perfused tissue to ionized acridines, barbiturates and desoxyglucose caused a prolongation of the action potentials. These actions as obtained were reversible. The e...

In vivo neocortical neurons fire apparently random trains of action potentials in response to sensory stimuli. Does this randomness represent a signal or noise around a mean firing rate? Here we use the timing of action potential trains recorded in vivo to explore the dendritic consequences of physiological patterns of action potential firing in neocortical pyramidal neurons in vitro. We find t...

We present two further cases of the pharyngeal-cervical-brachial (PCB) form of GBS, with unfavourable outcome, showing dramatic dissociation between upper and lower body Symptoms. Both patients showed rapidly progressive motor denervation with disappearance of Compound Muscle Action Potentials (CMAPs) in upper limbs muscles. Sensory Nerve Action Potentials (SNAPs) were instead normal. Normal re...

This work examined how quinine, a drug that induces both hearing loss and tinnitus, interfered with the excitability of spiral ganglion (SG) neurons in cultures. The membrane potential changes and the modification of the action-potential waveform induced by quinine were studied in SG neurons under current clamp. The effects of the drug on voltage-dependent currents in SG neurons were also inves...