This study aims to compare the electron spin resonance (ESR) spectra emitted by human blood loaded with either ascorbyl-6-palmitate (AP), a lipid-soluble derivative of ascorbic acid (AA), or with AA. Whole blood of a healthy male individual was equilibrated with equimolar concentrations of AP and AA of 200, 400, and 800 micromol/l. The intensity of the ESR signal, expressed as the peak-to-peak ...

The generation of an action potential (AP) is a complex process in excitable cells that involves the temporal opening and closing of several voltage-dependent ion channels within the cell membrane. The shape of an AP can carry information concerning the state of the involved ion channels as well as their relationship to cellular processes. Alteration of these ion channels by the administration ...

ion channels are responsible for control of cell function in excitable tissues such as heart and brain and also in organs and tissues traditionally thought to be non- excitable including liver and epithelium. in the present research, the effect of lead (pb2+) on ca2+ -dependent action potential and currents was studied in f77 neuronal soma membrane of helix aspersa. for this purpose, action pot...

A-type potassium channels regulate neuronal firing frequency and the back-propagation of action potentials (APs) into dendrites of hippocampal CA1 pyramidal neurones. Recent molecular cloning studies have found several families of voltage-gated K(+) channel genes expressed in the mammalian brain. At present, information regarding the relationship between the protein products of these genes and ...

In the mammalian main olfactory bulb (MOB), the release of glutamate from lateral dendrites of mitral cells onto the dendrites of granule cells evokes recurrent and lateral inhibition of mitral cell activity. Whole-cell voltage recordings in the mouse MOB in vivo and in vitro show that recurrent and lateral inhibition together control the number, duration, and onset of odor-evoked action potent...

The discrete arrangement of voltage-gated K(+) (Kv) channels in axons may impart functional advantages in action potential (AP) signaling yet, in compact cell types, the organization of Kv channels is poorly understood. We find that in cerebellar stellate cell interneurons of mice, the composition and influence of Kv channels populating the axon is diverse and depends on location allowing axona...

High-frequency action potential (AP) transmission is essential for rapid information processing in the central nervous system. Voltage-dependent Kv3 channels play an important role in this process thanks to their high activation threshold and fast closure kinetics, which reduce the neuron's refractory period. However, premature Kv3 channel closure leads to incomplete membrane repolarization, pr...

AIMS To study the properties of ion-channel gating (I(Ks), the slow delayed rectifier K+ channel) that underlie the channel's participation in rate-dependent repolarization of the cardiac action potential (AP). METHODS Computational biology approach was used to simulate the channel gating and the AP of a mammalian ventricular myocyte. RESULTS At fast rate, channels accumulate at closed stat...

Action potential (AP) generation in inhibitory interneurons is critical for cortical excitation-inhibition balance and information processing. However, it remains unclear what determines AP initiation in different interneurons. We focused on two predominant interneuron types in neocortex: parvalbumin (PV)- and somatostatin (SST)-expressing neurons. Patch-clamp recording from mouse prefrontal co...

Action potential (AP) generation at the plasmalemma of Chara corallina has a strong influence on photoprocesses in chloroplasts. Under physiological conditions the AP generation transiently suppresses photosynthetic electron transport and reversibly increases thermal losses of chlorophyll excitations. However, these changes provoked by membrane excitation became irreversible in the presence of ...