Recent investigations have shown the ability of ascorbyl palmitate (AP), a bioactive, lipid-soluble ester of ascorbic acid (AA), to penetrate neural tissues. This study seeks to determine the occurrence of hydrolysis of AP molecule in brain tissue, which could rather point to the action of AA alone carried over the biological barrier and then released from the AP compound. The integrity of AP m...

Action potential (AP) profiles vary based on the cell type, with cells of the same type typically producing APs with similar shapes. But in certain syncytial tissues, such as the smooth muscle of the urinary bladder wall, even a single cell is known to exhibit APs with diverse profiles. The origin of this diversity is not currently understood, but is often attributed to factors such as syncytia...

The role of dendritic voltage-gated ion channels in the generation of action potential bursting was investigated using whole cell patch-clamp recordings from the soma and dendrites of CA1 pyramidal neurons located in hippocampal slices of adult rats. Under control conditions somatic current injections evoked single action potentials that were associated with an afterhyperpolarization (AHP). Aft...

According to theoretical and clinical considerations the risk of re-entry type malignant arrhythmia can be predicted by body surface QRST integral maps. Our aim was to understand better the intracardiac processes causing noninvasively measurable action potential (AP) heterogeneity. For this task we used a computer model of human cardiac ventricles with modifiable AP patterns to investigate the ...

Introduction: Although aging is the most important risk factor for Alzheimer's disease (AD), there is evidence indicating that neuroinflammation may contribute to the development and progression of the disease. Several studies indicated that minocycline may exert neuroprotective effects in rodent models of neurodegenerative diseases. Nevertheless, there are also other studies implying that ...

In a recent article in the Jpn J Physiol Matsuoka et al. [1] present in their discussion section a comparison of their cardiac action potential model and the Luo-Rudy dynamic (LRd) model [2]. Figure 10 in their paper compares the action potential (AP), calcium transient (CaT) and selected ionic currents during the AP. Several results of their LRd simulations are conducted using parameters/proto...

CONCLUSIONS Our results suggest that summating potential/action potential (SP/AP) area ratio may not necessarily have higher sensitivity in the diagnosis of endolymphatic hydrops of Meniere's disease (MD) than SP/AP amplitude ratio in transtympanic electrocochleography (ECochG). OBJECTIVE Recent studies suggested that SP/AP area curve ratio was more sensitive to endolymphatic hydrops in compa...

Upon stimulation, excitable cells generate a transient change in the membrane potential called Action Potential (AP). The AP is governed by numerous ionic currents that flow in or out of the cell membrane. The goal of cellular electrophysiology is to understand the role of individual ionic currents and the interplay between currents in determining the profile and the time course of AP. A critic...

Action potential (AP) alternans has been well established as a mechanism of arrhythmogenesis and sudden cardiac death. Proper interpretation of AP alternans requires a robust method of alternans quantification. Traditional methods of alternans analysis neglect higher order periodicities that may have greater pro-arrhythmic potential than classical 2:1 alternans. The spectral method of alternans...

Large-conductance Ca(2+)-activated K(+) channels (BK, also called Maxi-K or Slo channels) are widespread in the vertebrate nervous system, but their functional roles in synaptic transmission in the mammalian brain are largely unknown. By combining electrophysiology and immunogold cytochemistry, we demonstrate the existence of functional BK channels in presynaptic terminals in the hippocampus an...