Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
The dynamic-clamp electrophysiological technique allows the mimicking of the electrical effects of arbitrary ion channels, controlled by the experimentalist, activating and inactivating into the membrane of an intracellularly recorded biological cell. Dynamic clamp relies on the establishing of a loop between the injected current and the recorded membrane potential. In this introductory chapter, we...
Central neurons receive the majority of synaptic input at dendritic sites. Classical models of neuronal function suggest that dendrites simply funnel synaptic input to the site of action potential initiation in the axon. Direct dendritic whole-cell recording techniques have however demonstrated that dendrites are electrically excitable. Recently, the dynamic clamp has been used to simulate synaptic...
Investigating how cortical neurons integrate their electrical inputs has commonly involved injecting fixed patterns of current and observing the resulting membrane potential and spike responses. However, we now have accurate biophysical models of the ionic conductances at the postsynaptic sites of cortical synapses and of the conductances which generate action potentials (APs). Using conductance injection...
Neurons in vivo receive a large amount of internally generated “background” activity in addition to synaptic input directly driven by an external stimulus. Stimulus-driven and background synaptic inputs interact, through the nonlinearities of neuronal integration, in interesting ways. The dynamic clamp can be used in vitro to duplicate background input, allowing the experimenter to take advantage...
Neurons in the intact brain are bombarded by spontaneous synaptic input that causes increased membrane conductance (i.e. shunting), tonic depolarization, and noisy fluctuations in membrane potential. By comparison, neurons in acute brain slices experience little spontaneous synaptic input and are therefore less leaky, more hyperpolarized, and less noisy. Such differences can compromise the extrapolation...
In this chapter, we present different methods to analyze intracellular recordings and the testing of these methods using dynamic-clamp techniques. The methods are derived from a model of synaptic background activity where the synaptic membrane conductances are considered as stochastic processes. Because this fluctuating point-conductance model can be treated analytically, different methods can be...
We present in vivo dynamic-clamp electrophysiological recordings to characterize the influences of shunting inhibition and the potassium current IBK on the input–output (I/O) transfer function of cortical neurons, in response to both artificial (injected current or conductance) and functional visual stimuli. In comparison to previous experimental and theoretical studies, we find that realistic...
Many cortical neurons and other vertebrate nerve cells are equipped with a persistent Na+ current, INaP, which operates at membrane potentials near the action potential threshold. This current may strongly influence integration and transduction of synaptic input into spike patterns. However, due to the lack of pharmacological tools for selective blockade or enhancement of INaP...
We report on development and use of dynamic-clamp technology to understand how synchronous neuronal activity is generated in the hippocampus and entorhinal cortex. We find that “hard” real-time dynamic-clamp systems, characterized by very small maximal errors in timing of feedback, are necessary for cases in which fast voltage-gated channels are being mimicked in experiments. Using a hard real-time...
In this chapter we demonstrate how dynamic clamping can be used to apply different types of conductances to neurons in the deep cerebellar nuclei (DCN) to explore how spiking in these neurons is controlled by the interaction of synaptic and intrinsic conductances. Besides the application of synaptic- and voltage-gated conductances, we introduce the modeling of an intracellular calcium pool in the...
Cortical cells belong to small interconnected ensembles. These ensembles have the potential of being activated in a reverberatory fashion in vitro and in vivo, spontaneously or in response to stimulation. We combined computer simulations and in vitro intracellular recording from prefrontal cortical neurons to explore the elicitation, modulation, and termination of these reverberations. In computer...
Hybrid circuits comprised of one biological bursting neuron and one model bursting neuron were constructed using the dynamic clamp to create artificial synaptic conductances in both neurons. The strength and duration of reciprocal inhibitory and excitatory synaptic inputs were varied in a number of such circuits. The phase resetting curves (PRCs) for each component neuron were constructed for each...
Our goal is to understand how neural network dynamics depend on the properties of the component neurons and their synaptic connections. To that end, we propose a novel method using the dynamic clamp to evaluate the intrinsic properties of isolated neurons that replaces conventional methods such as measuring input impedance. Secondly, we construct novel circuits using the dynamic clamp by electrically...
Understanding the input–output transfer properties of NEURONs is a complex problem which requires detailed knowledge of the intrinsic properties of neurons, and how these intrinsic properties influence signal integration. More recently, it became clear that the transfer function of neurons also highly depends on the activity of the surrounding network, and in particular on the presence of synaptic...
During different stages of vigilance, the thalamus engages in a range of rhythmic activities from the slow (<1 Hz), delta (δ) (1–4 Hz) and spindle (7–14 Hz) waves that permeate the brain during sleep and anaesthesia to the faster oscillations in the alpha (α) and beta/gamma (β/γ) (>15 Hz) bands that occur during wakefulness. In recent years, it has been shown that several of these oscillations...
The active electrode compensation (AEC) consists of an online correction of the recorded membrane potential based on a computational model of the electrode. This technique may be particularly useful for situations where high-frequency components (such as noise) must be injected. This is particularly important for dynamic-clamp applications because of the real-time feedback between injected current...
The dynamic-clamp technique has been recognized and used by electrophysiologists for over 15 years. Nevertheless, only a small number of papers have been written focusing on the performance and reliability of this protocol and how the accuracy of a dynamic-clamp system can be assessed. Here we review the published literature to date, focusing on how experimental, computational, and algorithmic factors...
In this chapter, we briefly review the use of dynamic clamp in cardiac cellular electrophysiology and present novel results obtained with the ‘dynamic action potential clamp’ (dAPC) technique. This is a technique that we recently developed to study the effects of long-QT syndrome-related ion channel mutations by effectively replacing the associated native ionic current of a cardiac myocyte with wild-type...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.