We investigated the types and distribution of voltage-gated K+ channels in soma apical dendrite layer 5 (L5) neocortical pyramidal neurones, young rats (postnatal days 13-15), acute brain slices. A slow inactivating outward current a fast were detected nucleated patches. The was completely blocked by tetraethylammonium (TEA) with an IC50 +/- 1 mM (mean s.e.m.) partially 4-aminopyridine (4-AP). 4-AP 4.2 0.5 mM, but not TEA. activation kinetics described second order Hodgkin-Huxley model....

Transcranial magnetic stimulation (TMS) is a method in which coil generates field an area of interest the brain. This induces electric that modulates neuronal activity. The spatial distribution induced determined by geometry and location relative to Although TMS has been used for several decades, biophysical basis underlying neurons central nervous system (CNS) still unknown. To address this problem we developed numerical scheme enabling us combine realistic (MS) with compartmental modeling...

Compartmental models with many nonlinearly and nonhomogeneous distributions of voltage-gated conductances are routinely used to investigate the physiology complex neurons. However, number loosely constrained parameters makes manually constructing desired model a daunting if not impossible task. Recently, progress has been made using automated parameter search methods, such as genetic algorithms (GAs). these methods have applied somatically recorded action potentials relatively simple target...

The voltage-clamp technique is applicable only to spherical cells. In nonspherical cells, such as neurons, the membrane potential not clamped distal electrode. This means that current recorded by electrode sum of local and axial currents from locations experiencing different potentials. Furthermore, voltage-gated a cell are, definition, severely distorted due lack space clamp. Justifications for voltage clamping in cells first, clamp severe neurons with short dendrites. Second, passive cable...

Although transcranial magnetic stimulation (TMS) is a popular tool for both basic research and clinical applications, its actions on nerve cells are only partially understood. We have previously predicted, using compartmental modeling, that of central nervous system neurons depolarized the soma followed by initiation an action potential in initial segment axon. The simulations also predict with low current threshold more susceptible to stimulation. Here we tested these theoretical...

Postsynaptic integration is a complex function of passive membrane properties and nonlinear activation voltage-gated channels. Some cortical neurons express many channels, with each displaying heterogeneous dendritic conductance gradients. This complexity has hindered the construction experimentally based mechanistic models neurons. Here we show that it possible to overcome this obstacle. We recorded potential from soma apical dendrite layer 5 (L5) pyramidal rat somatosensory cortex. A...

Airway ciliated cells express an ATP-gated P2X receptor channel of unknown subunit composition (P2X(cilia)) which is modulated by Na+ and long exposures to ATP. P2X(cilia) was investigated recording currents from freshly dissociated rabbit airway with the patch-clamp technique in whole-cell configuration. During initial continuous exposure extracellular ATP, gradually increase magnitude (priming), yet permeability N-methyl-D-glucamine (NMDG) does not change, indicating that priming arise a...

The activity of trans-membrane proteins such as ion channels is the essence neuronal transmission. currently most accurate method for determining channel kinetic mechanisms single-channel recording and analysis. Yet, limitations complexities in interpreting recordings discourage many physiologists from using them. Here we show that a genetic search algorithm combination with gradient descent can be used to fit whole-cell voltage-clamp data models high degree accuracy. Previously, stimulation...

1. Simultaneous measurements of average intracellular calcium concentration ([Ca2+]i) and ciliary beat frequency (CBF) were carried out on ciliated rabbit tracheal cells in order to determine quantitatively the role regulation mucus‐transporting cilia. 2. Extracellular ATP caused a rapid increase both [Ca2+]i CBF 0.1‐1000 microM range. The rise levelled off an elevated plateau while cilia remained high activation state. magnitude as well value sustained dependent solution. 3. No correlation...

Extracellular recordings in primates have identified two types of neurons the external segment globus pallidus (GPe): high frequency pausers (HFP) and low bursters (LFB). The aim current study was to test whether properties HFP LFB recorded extracellularly primate GPe are linked cellular mechanisms underlying generation action potential (AP) firing. Thus, we from rat neurons. revealed that addition differences firing patterns APs these groups different widths (APex). To quantitatively...

A membrane conductance activated by extracellular ATP was identified and characterized in freshly dissociated rabbit airway ciliated cells using the whole‐cell outside‐out patch configurations of patch‐clamp technique. In solutions designed to maximize currents through voltage‐gated calcium channels, there were no indications Ba 2+ currents. Extracellular (but not UTP or ADP) a which remained for several minutes presence ATP. The permeable monovalent divalent cations with approximate...

Constructing physiologically relevant compartmental models of neurones is critical for understanding neuronal activity and function. We recently suggested that measurements from multiple locations along the soma, dendrites axon are necessary as a data set when using genetic optimization algorithm to constrain parameters model an entire neurone. However, recordings L5 pyramidal can routinely be performed simultaneously only two locations. Now we show recorded soma apical dendrite combined...

The firing patterns of neurons in the globus pallidus (GP) are affected by two major sources GABAergic inhibition: striatal afferents and local axon collaterals. Local GP-GP synapses display short-term depression (STD) very sparse connectivity. At high presynaptic rates typical GP, one would expect this STD to be complete, practically cancelling postsynaptic impact synapse. To investigate apparent paradox a synapse not affecting its neuron, we performed dual whole-cell recordings acute brain...

Voltage-gated sodium channels (Nav) are key players in excitable tissues with the capability to generate and propagate action potentials. Mutations genes encoding Navs can lead severe inherited diseases, some of these so-called channelopathies show temperature-sensitive phenotypes, for example, paramyotonia congenita, Brugada syndrome, febrile seizure syndromes, pain syndromes like erythromelalgia (IEM) paroxysmal extreme disorder (PEPD). Nevertheless, most investigations mutation-induced...

In the present work we report that increasing viscosity of medium caused not only a decrease in ciliary beat frequency but also changes metachrony and correlation between cilia. The study was performed using double triple simultaneous photoelectric measurements on cultured cells from frog esophagus range 1-2,000 cp. We observed intensified fluctuations all measured parameters. Ciliary decreased moderately. Even at quite high viscosities (circa 2000 cp.), cilia were still active with beating...

Voltage‐gated potassium channels effectively regulate dendritic excitability in neurones. It has been suggested that the distal apical dendrite of layer 5B (L5B) neocortical pyramidal neurones, K + conductances participate active synaptic integration and control regenerative potentials. The ionic mechanism for triggering these potentials yet to be elucidated. Here we used two‐electrode voltage clamp (TEVC) quantitatively record conductance densities a sustained soma L5B neurones adult rats....

Neuronal voltage-gated Ca2+ channels are involved in electrical signalling and converting these signals into cytoplasmic calcium changes. One important function of is generating regenerative dendritic spikes. However, the dependent mechanisms used to create spikes only partially understood. To start investigating this mechanism, we set out kinetically pharmacologically identify sub-types somatic pyramidal neurons from layer 5 rat somatosensory cortex, using nucleated configuration...

KCNQ2/KCNQ3 channels are the molecular correlates of neuronal M-channels, which play a major role in control excitability. Notably, they differ from homomeric KCNQ2 their distribution pattern within neurons, with unique expression axons and nerve terminals. Here, combined reciprocal coimmunoprecipitation two-electrode voltage clamp analyses Xenopus oocytes revealed strong association syntaxin 1A, component exocytotic SNARE complex, resulting ∼2-fold reduction macroscopic conductance slower...