scholarly journals Whisking-Related Changes in Neuronal Firing and Membrane Potential Dynamics in the Somatosensory Thalamus of Awake Mice

Cell Reports ◽  
2015 ◽  
Vol 13 (4) ◽  
pp. 647-656 ◽  
Author(s):  
Nadia Urbain ◽  
Paul A. Salin ◽  
Paul-Antoine Libourel ◽  
Jean-Christophe Comte ◽  
Luc J. Gentet ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Neuronal Firing ◽  
Somatosensory Thalamus

scholarly journals Brain-State-Dependent Modulation of Neuronal Firing and Membrane Potential Dynamics in the Somatosensory Thalamus during Natural Sleep

Cell Reports ◽  
2019 ◽  
Vol 26 (6) ◽  
pp. 1443-1457.e5 ◽  
Author(s):  
Nadia Urbain ◽  
Nicolas Fourcaud-Trocmé ◽  
Samuel Laheux ◽  
Paul A. Salin ◽  
Luc J. Gentet
Keyword(s):  
Membrane Potential ◽  
Neuronal Firing ◽  
Brain State ◽  
Natural Sleep ◽  
Somatosensory Thalamus ◽  
State Dependent

Measurement of spontaneous neuronal membrane activity by time lapse confocal microscopy

1995 ◽  
Vol 53 ◽  
pp. 972-973
Author(s):  
R H. Selinfreund ◽  
A. H. Cornell-Bell
Keyword(s):  
Membrane Potential ◽  
Confocal Microscopy ◽  
Patch Clamp ◽  
Electrical Activity ◽  
Time Lapse ◽  
Neuronal Firing ◽  
Neuronal Membrane ◽  
Pituitary Cells ◽  
Patch Clamp Recording ◽  
Spontaneous Electrical Activity

Cellular electrophysiological properties are normally monitored by standard patch clamp techniques . The combination of membrane potential dyes with time-lapse laser confocal microscopy provides a more direct, least destructive rapid method for monitoring changes in neuronal electrical activity. Using membrane potential dyes we found that spontaneous action potential firing can be detected using time-lapse confocal microscopy. Initially, patch clamp recording techniques were used to verify spontaneous electrical activity in GH4\C1 pituitary cells. It was found that serum depleted cells had reduced spontaneous electrical activity. Brief exposure to the serum derived growth factor, IGF-1, reconstituted electrical activity. We have examined the possibility of developing a rapid fluorescent assay to measure neuronal activity using membrane potential dyes. This neuronal regeneration assay has been adapted to run on a confocal microscope. Quantitative fluorescence is then used to measure a compounds ability to regenerate neuronal firing.The membrane potential dye di-8-ANEPPS was selected for these experiments. Di-8- ANEPPS is internalized slowly, has a high signal to noise ratio (40:1), has a linear fluorescent response to change in voltage.

scholarly journals Sub-optimal Discontinuous Current-Clamp switching rates lead to deceptive mouse neuronal firing

2020 ◽  
Author(s):  
Marin Manuel
Keyword(s):  
Membrane Potential ◽  
Neuronal Firing ◽  
Intracellular Recordings ◽  
Optimal Switching ◽  
Switching Rate ◽  
Current Clamp ◽  
Care Needs ◽  
Cell Potential ◽  
Cell Excitability

AbstractIntracellular recordings using sharp microelectrodes often rely on a technique called Discontinuous Current-Clamp to accurately record the membrane potential while injecting current through the same microelectrode. It is well known that a poor choice of DCC switching rate can lead to under-or over-estimation of the cell potential, however, its effect on the cell firing is rarely discussed. Here, we show that sub-optimal switching rates lead to an overestimation of cell excitability. We performed intracellular recordings of mouse spinal motoneurons and recorded their firing in response to pulses and ramps of current in Bridge and DCC mode at various switching rates. We demonstrate that using an incorrect (too low) DCC frequency leads not only to an underestimation of the input resistance, but also, paradoxically, to an artificial overestimation of the firing of these cells: neurons fire at lower current, and at higher frequencies than at higher DCC rates, or than the same neuron recorded in Bridge mode. These effects are dependent on the membrane time constant of the recorded cell, and special care needs to be taken in large cells with very short time constants. Our work highlights the importance of choosing an appropriate DCC switching rate to obtain not only accurate membrane potential readings but also an accurate representation of the firing of the cell.Significance StatementDiscontinuous Current-Clamp is a technique often used during intracellular recordings in vivo. However, incorrect usage of this technique can lead to incorrect interpretations. Poor choice of the DCC switching rate can lead to under- or over-estimation of the cell potential. In addition, we show here that sub-optimal switching rates lead to an overestimation of the cell excitability.

Introduction

1998 ◽  
Author(s):  
Christof Koch
Keyword(s):  
Membrane Potential ◽  
Nerve Cells ◽  
Neuronal Firing ◽  
Western World ◽  
Long Term Memory ◽  
Sensory Data ◽  
Relevant Variables ◽  
Elementary Circuit ◽  
Circuit Designer ◽  
The Brain

The brain computes! This is accepted as a truism by the majority of neuroscientists engaged in discovering the principles employed in the design and operation of nervous systems. What is meant here is that any brain takes the incoming sensory data, encodes them into various biophysical variables, such as the membrane potential or neuronal firing rates, and subsequently performs a very large number of ill-specified operations, frequently termed computations, on these variables to extract relevant features from the input. The outcome of some of these computations can be stored for later access and will, ultimately, control the motor output of the animal in appropriate ways. The present book is dedicated to understanding in detail the biophysical mechanisms responsible for these computations. Its scope is the type of information processing underlying perception and motor control, occurring at the millisecond to fraction of a second time scale. When you look at a pair of stereo images trying to fuse them into a binocular percept, your brain is busily computing away trying to find the “best” solution. What are the computational primitives at the neuronal and subneuronal levels underlying this impressive performance, unmatched by any machine? Naively put and using the language of the electronic circuit designer, the book asks: “What are the diodes and the transistors of the brain?” and “What sort of operations do these elementary circuit elements implement?” Contrary to received opinion, nerve cells are considerably more complex than suggested by work in the neural network community. Like morons, they are reduced to computing nothing but a thresholded sum of their inputs. We know, for instance, that individual nerve cells in the locust perform an operation akin to a multiplication. Given synapses, ionic channels, and membranes, how is this actually carried out? How do neurons integrate, delay, or change their output gain? What are the relevant variables that carry information? The membrane potential? The concentration of intracellular Ca2+ ions? What is their temporal resolution? And how large is the variability of these signals that determines how accurately they can encode information? And what variables are used to store the intermediate results of these computations? And where does long-term memory reside? Natural philosophers and scientists in the western world have always compared the brain to the most advanced technology of the day.

Ionic basis for endogenous rhythmic patterns induced by activation of N-methyl-D-aspartate receptors in neurons of the rat nucleus tractus solitarii

1993 ◽  
Vol 70 (6) ◽  
pp. 2379-2390 ◽  
Author(s):  
F. Tell ◽  
A. Jean
Keyword(s):  
Membrane Potential ◽  
Neuronal Firing ◽  
Calcium Currents ◽  
Nucleus Tractus Solitarii ◽  
Repetitive Firing ◽  
Potential Range ◽  
Electrophysiological Properties ◽  
Ionic Mechanisms ◽  
Discharge Patterns

1. Activation of N-methyl-D-aspartate (NMDA) receptors in caudal nucleus tractus solitarii (cNTS) neurons elicited endogenous rhythmic activities. We used an in vitro brain stem slice preparation to determine the ionic mechanisms underlying the generation of these activities. 2. Using intracellular recordings, we found several ionic conductances to be responsible for the electrophysiological properties of cNTS neurons. After addition of tetrodotoxin (TTX) to the perfusate, cNTS neurons were still able to generate action potentials (APs). Because these APs were suppressed by the addition of cobalt or by the reduction of calcium, they were likely due to calcium currents (ICa). In addition, the amplitude of the afterhyperpolarization (AHP) that followed a train of TTX-resistant APs was reduced in both low-calcium and cobalt-containing saline. It was therefore suggested that calcium-activated potassium (IKCa) currents were involved in the AHP. Accordingly, application of apamin, a blocker of slow IKCa, also decreased the AHP. cNTS neurons exhibited a delayed excitation phenomenon, characterized by a ramplike depolarization that delayed the onset of neuronal firing, when they were depolarized from hyperpolarizing potential. The underlying current was presumed to be an A-current (IKA), because this phenomenon was suppressed during application of 4-aminopyridine (4-AP). 3. Application of NMDA elicited different types of discharge patterns in cNTS neurons: a repetitive firing at depolarized levels of membrane potential (above -60 mV) and rhythmic patterns characterized by either rhythmic bursting or rhythmic single discharges at hyperpolarized levels (within membrane potential range of -60 to -85 mV). In all neurons, rhythmic patterns were superimposed on oscillations of membrane potential. They were characterized by a sudden shift of membrane potential, followed by a ramp-shaped phase of depolarization that preceded spike elicitation. Addition of TTX to the saline did not suppress NMDA-induced oscillations. Therefore rhythmic patterns were not driven by synaptic mechanisms but resulted from endogenous properties of cNTS neurons. 4. APs superimposed on NMDA-induced depolarizations presented the same characteristics as those elicited by positive current pulses. NMDA-elicited oscillations of membrane potential were eliminated by removing magnesium from the saline. Therefore oscillation generation was based primarily on the NMDA channel properties. 5. Intrinsic conductances of cNTS neurons interacted with NMDA-gated conductances to shape the depolarization waveform. Because removal of calcium from the saline suppressed endogenous oscillations, ICa currents were required for the expression of rhythmic activities. IKCa currents were involved in the repolarization phase of oscillations because apamin increased the duration of the oscillations.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals TRPM4 Expression During Postnatal Developmental of Mouse CA1 Pyramidal Neurons

2021 ◽  
Vol 15 ◽  
Author(s):  
Denise Riquelme ◽  
Oscar Cerda ◽  
Elias Leiva-Salcedo
Keyword(s):  
Membrane Potential ◽  
Patch Clamp ◽  
Postnatal Development ◽  
Pyramidal Neurons ◽  
Brain Slices ◽  
Long Term Potentiation ◽  
Neuronal Firing ◽  
Resting Membrane Potential ◽  
Ca1 Pyramidal Neurons ◽  
Apical Dendrites

TRPM4 is a non-selective cation channel activated by intracellular calcium and permeable to monovalent cations. This channel participates in the control of neuronal firing, neuronal plasticity, and neuronal death. TRPM4 depolarizes dendritic spines and is critical for the induction of NMDA receptor-dependent long-term potentiation in CA1 pyramidal neurons. Despite its functional importance, no subcellular localization or expression during postnatal development has been described in this area. To examine the localization and expression of TRPM4, we performed duplex immunofluorescence and patch-clamp in brain slices at different postnatal ages in C57BL/6J mice. At P0 we found TRPM4 is expressed with a somatic pattern. At P7, P14, and P35, TRPM4 expression extended from the soma to the apical dendrites but was excluded from the axon initial segment. Patch-clamp recordings showed a TRPM4-like current active at the resting membrane potential from P0, which increased throughout the postnatal development. This current was dependent on intracellular Ca2+ (ICAN) and sensitive to 9-phenanthrol (9-Ph). Inhibiting TRPM4 with 9-Ph hyperpolarized the membrane potential at P14 and P35, with no effect in earlier stages. Together, these results show that TRPM4 is expressed in CA1 pyramidal neurons in the soma and apical dendrites and associated with a TRPM4-like current, which depolarizes the neurons. The expression, localization, and function of TRPM4 throughout postnatal development in the CA1 hippocampal may underlie an important mechanism of control of membrane potential and action potential firing during critical periods of neuronal development, particularly during the establishment of circuits.

scholarly journals Subthreshold Membrane-Potential Resonances Shape Spike-Train Patterns in the Entorhinal Cortex

2008 ◽  
Vol 100 (3) ◽  
pp. 1576-1589 ◽  
Author(s):  
T. A. Engel ◽  
L. Schimansky-Geier ◽  
A.V.M. Herz ◽  
S. Schreiber ◽  
I. Erchova
Keyword(s):  
Membrane Potential ◽  
Entorhinal Cortex ◽  
Rhythmic Activity ◽  
Cell Types ◽  
Neuronal Firing ◽  
Type Model ◽  
Fundamental Properties ◽  
Subthreshold Oscillations ◽  
Subthreshold Resonance ◽  
Specific Discharge

Many neurons exhibit subthreshold membrane-potential resonances, such that the largest voltage responses occur at preferred stimulation frequencies. Because subthreshold resonances are known to influence the rhythmic activity at the network level, it is vital to understand how they affect spike generation on the single-cell level. We therefore investigated both resonant and nonresonant neurons of rat entorhinal cortex. A minimal resonate-and-fire type model based on measured physiological parameters captures fundamental properties of neuronal firing statistics surprisingly well and helps to shed light on the mechanisms that shape spike patterns: 1) subthreshold resonance together with a spike-induced reset of subthreshold oscillations leads to spike clustering and 2) spike-induced dynamics influence the fine structure of interspike interval (ISI) distributions and are responsible for ISI correlations appearing at higher firing rates (≥3 Hz). Both mechanisms are likely to account for the specific discharge characteristics of various cell types.

Interactive Effects of the GABABergic Modulation of Calcium Channels and Calcium-Dependent Potassium Channels in Lamprey

1999 ◽  
Vol 81 (3) ◽  
pp. 1318-1329 ◽  
Author(s):  
Jesper Tegnér ◽  
Sten Grillner
Keyword(s):  
Membrane Potential ◽  
Potassium Channels ◽  
Calcium Channels ◽  
Receptor Activation ◽  
Neuronal Firing ◽  
Calcium Currents ◽  
Interactive Effects ◽  
Potential Oscillations ◽  
Calcium Dependent ◽  
Membrane Potential Oscillations

Interactive effects of the GABABergic modulation of calcium channels and calcium-dependent potassium channels in lamprey. The GABAB-mediated modulation of spinal neurons in the lamprey is investigated in this study. Activation of GABAB receptors reduces calcium currents through both low- (LVA) and high-voltage activated (HVA) calcium channels, which subsequently results in the reduction of the calcium-dependent potassium (KCa) current. This in turn will reduce the peak amplitude of the afterhyperpolarization (AHP). We used the modulatory effects of GABAB receptor activation on N-methyl-d-aspartate (NMDA)-induced, TTX-resistant membrane potential oscillations as an experimental model in which to separate the effects of GABAB receptor activation on LVA calcium channels from that on KCachannels. We show experimentally and by using simulations that a direct effect on LVA calcium channels can account for the effects of GABAB receptor activation on intrinsic membrane potential oscillations to a larger extent than indirect effects mediated via KCa channels. Furthermore, by conducting experiments and simulations on intrinsic membrane potential oscillations, we find that KCa channels may be activated by calcium entering through LVA calcium channels, providing that the decay kinetics of the calcium that enters through LVA calcium channels is not as slow as the calcium entering via NMDA receptors. A combined experimental and computational analysis revealed that the LVA calcium current also contributes to neuronal firing properties.

Origins of 1/f2 scaling in the power spectrum of intracortical local field potential

2012 ◽  
Vol 107 (3) ◽  
pp. 984-994 ◽  
Author(s):  
Gytis Baranauskas ◽  
Emma Maggiolini ◽  
Alessandro Vato ◽  
Giannicola Angotzi ◽  
Andrea Bonfanti ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Power Spectrum ◽  
Local Field ◽  
Local Field Potential ◽  
Field Potential ◽  
Neuronal Firing ◽  
Neuronal Membrane ◽  
Up States ◽  
Up And Down States ◽  
Spiking Activity

It has been noted that the power spectrum of intracortical local field potential (LFP) often scales as 1/f−2. It is thought that LFP mostly represents the spiking-related neuronal activity such as synaptic currents and spikes in the vicinity of the recording electrode, but no 1/f2 scaling is detected in the spike power. Although tissue filtering or modulation of spiking activity by UP and DOWN states could account for the observed LFP scaling, there is no consensus as to how it arises. We addressed this question by recording simultaneously LFP and single neurons (“single units”) from multiple sites in somatosensory cortex of anesthetized rats. Single-unit data revealed the presence of periods of high activity, presumably corresponding to the “UP” states when the neuronal membrane potential is depolarized, and periods of no activity, the putative “DOWN” states when the membrane potential is close to resting. As expected, the LFP power scaled as 1/f2 but no such scaling was found in the power spectrum of spiking activity. Our analysis showed that 1/f2 scaling in the LFP power spectrum was largely generated by the steplike transitions between UP and DOWN states. The shape of the LFP signal during these transitions, but not the transition timing, was crucial to obtain the observed scaling. These transitions were probably induced by synchronous changes in the membrane potential across neurons. We conclude that a 1/f2 scaling in the LFP power indicates the presence of steplike transitions in the LFP trace and says little about the statistical properties of the associated neuronal firing.

Fluorescent potentiometric dyes for membrane-potential imaging

1994 ◽  
Vol 52 ◽  
pp. 166-167
Author(s):  
Leslie M. Loew
Keyword(s):  
Membrane Potential ◽  
Single Cells ◽  
Quantitative Imaging ◽  
Optical Recording ◽  
Biological Processes ◽  
Major Focus ◽  
The Past ◽  
Excitable Systems ◽  
Major Application ◽  
The Impact

A major application of potentiometric dyes has been the multisite optical recording of electrical activity in excitable systems. After being championed by L.B. Cohen and his colleagues for the past 20 years, the impact of this technology is rapidly being felt and is spreading to an increasing number of neuroscience laboratories. A second class of experiments involves using dyes to image membrane potential distributions in single cells by digital imaging microscopy - a major focus of this lab. These studies usually do not require the temporal resolution of multisite optical recording, being primarily focussed on slow cell biological processes, and therefore can achieve much higher spatial resolution. We have developed 2 methods for quantitative imaging of membrane potential. One method uses dual wavelength imaging of membrane-staining dyes and the other uses quantitative 3D imaging of a fluorescent lipophilic cation; the dyes used in each case were synthesized for this purpose in this laboratory.

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