scholarly journals NeuroGrid: recording action potentials from the surface of the brain

2014 ◽  
Vol 18 (2) ◽  
pp. 310-315 ◽  
Author(s):  
Dion Khodagholy ◽  
Jennifer N Gelinas ◽  
Thomas Thesen ◽  
Werner Doyle ◽  
Orrin Devinsky ◽  
...  
Keyword(s):  
Action Potentials ◽  
The Brain

Ephaptic Coupling in Hybrid Neuronal Model

2021 ◽  
Author(s):  
Gabriel Moreno Cunha ◽  
Gilberto Corso ◽  
José Garcia Vivas Miranda ◽  
Gustavo Zampier Dos Santos Lima
Keyword(s):  
Electric Fields ◽  
Action Potentials ◽  
Population Vector ◽  
Input Stimulus ◽  
Circular Statistic ◽  
Coupling Behavior ◽  
The Impact ◽  
The Brain ◽  
Ephaptic Coupling ◽  
Phase Differences

Abstract In recent decades, there has been growing interest in the impact of electric fields generated in the brain. Transmembrane ionic currents originate electric fields in the extracellular space and are capable of affecting nearby neurons, a phenomenon called ephaptic neuronal communication. In the present work, the Quadratic Integrate-and-Trigger model (QIF-E) underwent an adjustment/improvement to include the ephaptic coupling behavior between neurons and their results are compared to the empirical results. In this way, the analysis tools are employed according to the neuronal activity regime: (i) for the subthreshold regime, the circular statistic is used to describe the phase differences between the input stimulus signal and the modeled membrane response; (ii) in the suprathreshold regime, the Population Vector and the Spike Field Coherence are employed to estimate phase preferences and the coupling intensity between the input stimulus and the Action Potentials. The results observed are i) in the subthreshold regime the values of the phase differences change with distinct frequencies of an input stimulus; ii) in the supra-threshold regime the preferential phase of Action Potentials changes for different frequencies. In addition, we explore other parameters of the model, such as noise and membrane characteristic-time, in order to understand different types of neurons and extracellular environment related to ephaptic communication. Such results are consistent with results observed in empirical experiments based on ephaptic coupling behavior. In addition, the QIF-E model allows further studies on the physiological importance of ephaptic coupling in the brain, and its simplicity can open a door to simulating ephaptic coupling in neuron networks and evaluating the impact of ephaptic communication in such scenarios.

scholarly journals Apical length governs computational diversity of L5 pyramidal neurons

2019 ◽  
Author(s):  
Alessandro R. Galloni ◽  
Aeron Laffere ◽  
Ede Rancz
Keyword(s):  
Action Potentials ◽  
Pyramidal Neurons ◽  
Apical Dendrite ◽  
Common Assumption ◽  
Dendritic Excitability ◽  
Visual Cortices ◽  
The Common ◽  
Channel Dependent ◽  
Apical Dendrites ◽  
The Brain

AbstractAnatomical similarity across the neocortex has led to the common assumption that the circuitry is modular and performs stereotyped computations. Layer 5 pyramidal neurons (L5PNs) in particular are thought to be central to cortical computation because of their extensive arborisation and nonlinear dendritic operations. Here, we demonstrate that computations associated with dendritic Ca2+ plateaus in L5PNs vary substantially between the primary and secondary visual cortices. L5PNs in the secondary visual cortex show reduced dendritic excitability and smaller propensity for burst firing. This reduced excitability is correlated with shorter apical dendrites. Using numerical modelling, we uncover a universal principle underlying the influence of apical length on dendritic backpropagation and excitability, based on a Na+ channel-dependent broadening of backpropagating action potentials. In summary, we provide new insights into the modulation of dendritic excitability by apical dendrite length and show that the operational repertoire of L5 neurons is not universal throughout the brain.

Forward Dendritic Spikes

2011 ◽  
pp. 42-59
Author(s):  
Oscar Herreras ◽  
Julia Makarova ◽  
José Manuel Ibarz
Keyword(s):  
Action Potentials ◽  
Remarkable Property ◽  
Synaptic Inputs ◽  
Brain Circuits ◽  
Voltage Dependent ◽  
Dendritic Spikes ◽  
Underlying Mechanisms ◽  
The Brain ◽  
Made In

Neurons send trains of action potentials to communicate each other. Different messages are issued according to varying inputs, but they can also mix them up in a multiplexed language transmitted through a single cable, the axon. This remarkable property arises from the capability of dendritic domains to work semi autonomously and even decide output. We review the underlying mechanisms and theoretical implications of the role of voltage-dependent dendritic currents on the forward transmission of synaptic inputs, with special emphasis in the initiation, integration and forward conduction of dendritic spikes. When these spikes reach the axon, output decision was made in one of many parallel dendritic substations. When failed, they still serve as an internal language to transfer information between dendritic domains. This notion brakes with the classic view of neurons as the elementary units of the brain and attributes them computational/storage capabilities earlier billed to complex brain circuits.

Spatiotemporal Conversion of Auditory Information for Cochleotopic Mapping

2007 ◽  
Vol 19 (2) ◽  
pp. 351-370 ◽  
Author(s):  
Osamu Hoshino
Keyword(s):  
Action Potentials ◽  
Delay Line ◽  
Primary Auditory Cortex ◽  
Auditory Information ◽  
Latency Time ◽  
Delay Lines ◽  
Time Intervals ◽  
Communication Signals ◽  
Cortical Areas ◽  
The Brain

Auditory communication signals such as monkey calls are complex FM vocal sounds and in general induce action potentials in different timing in the primary auditory cortex. Delay line scheme is one of the effective ways for detecting such neuronal timing. However, the scheme is not straightforwardly applicable if the time intervals of signals are beyond the latency time of delay lines. In fact, monkey calls are often expressed in longer time intervals (hundreds of milliseconds to seconds) and are beyond the latency times observed in the brain (less than several hundreds of milliseconds). Here, we propose a cochleotopic map similar to that in vision known as a retinotopic map. We show that information about monkey calls could be mapped on a cochleotopic cortical network as spatiotemporal firing patterns of neurons, which can then be decomposed into simple (linearly sweeping) FM components and integrated into unified percepts by higher cortical networks. We suggest that the spatiotemporal conversion of auditory information may be essential for developing the cochleotopic map, which could serve as the foundation for later processing, or monkey call identification by higher cortical areas.

An Integrated Molar/Molecular Model of the Brain

1972 ◽  
Vol 30 (2) ◽  
pp. 343-368 ◽  
Author(s):  
Alan Einar Hendrickson
Keyword(s):  
Action Potentials ◽  
Short Term Memory ◽  
Molecular Model ◽  
Spike Trains ◽  
Mass Action ◽  
Small Species ◽  
Short Term ◽  
Term Memory ◽  
Anaesthetic Agents ◽  
The Brain

A model of the brain is presented at both molecular and molar levels. Communication between neurons is thought to be a kind of telegraph code, with the information being coded as the permutation of four possible interval values between successive action potentials in spike trains. A small species of RNA molecule is thought to be the memory molecule, and the four possible nucleotide bases of RNA correspond to the four possible interval values. The model is shown to account for generalization, speed of retrieval, mass action, long- and short-term memory, forgetting, operant and classical conditioning, intelligence, reaction time, the action of anaesthetic agents, and some aspects of personality. Some evidence from multidisciplinary sources is presented in support of the major features of the model.

scholarly journals Contribution of the axon initial segment to action potentials recorded extracellularly

2018 ◽  
Author(s):  
Maria Teleńczuk ◽  
Romain Brette ◽  
Alain Destexhe ◽  
Bartosz Teleńczuk
Keyword(s):  
Action Potential ◽  
Electric Fields ◽  
Action Potentials ◽  
Initial Segment ◽  
Initiation Site ◽  
Axon Initial Segment ◽  
Neuron Activity ◽  
Classical Models ◽  
The Brain

AbstractAction potentials (APs) are electric phenomena that are recorded both intracellularly and extracellularly. APs are usually initiated in the short segment of the axon called the axon initial segment (AIS). It was recently proposed that at onset of an AP the soma and the AIS form a dipole. We study the extracellular signature (the extracellular action potential, EAP) generated by such a dipole. First, we demonstrate the formation of the dipole and its extracellular signature in detailed morphological models of a reconstructed pyramidal neuron. Then, we study the EAP waveform and its spatial dependence in models with axonal AP initiation and contrast it with the EAP obtained in models with somatic AP initiation. We show that in the models with axonal AP initiation the dipole forms between somatodendritic compartments and the AIS, and not between soma and dendrites as in the classical models. Soma-dendrites dipole is present only in models with somatic AP initiation. Our study has consequences for interpreting extracellular recordings of single-neuron activity and determining electrophysiological neuron types, but also for better understanding the origins of the high-frequency macroscopic electric fields recorded in the brain.New & NoteworthyWe studied the consequences of the action potential (AP) initiation site on the extracellular signatures of APs. We show that: (1) at the time of AP initiation the action initial segment (AIS) forms a dipole with the soma, (2) the width but not (3) amplitude of the extracellular AP generated by this dipole increases with the soma-AIS distance. This may help to monitor dynamic changes in the AIS position in experimental in vivo recordings.

scholarly journals Investigating the Cocaine-induced Reduction of Potassium Current on the Generation of Action Potentials Using a Computational Model

2021 ◽  
Author(s):  
Hadi Borjkhani ◽  
◽  
Mehdi Borjkhani ◽  
Morteza A. Sharif ◽  
◽  
...  
Keyword(s):  
Computational Model ◽  
Action Potentials ◽  
Potassium Current ◽  
Drugs Of Abuse ◽  
Potassium Conductance ◽  
Brain Regions ◽  
Chaotic Regime ◽  
Chaotic Oscillations ◽  
Sodium Potassium ◽  
The Brain

Introduction: Drugs of abuse, including cocaine, affect different brain regions and lead to pathological memories. These abnormal memories may occur due to the changes in synaptic transmissions or variations in synaptic properties of neurons. It has been shown that cocaine inhibits delayed rectifying potassium currents in affected regions of the brain and can have a role in the formation of pathological memories. Purpose: This study investigates how the change in the conductance of delayed rectifying potassium channels can affect the produced action potentials using a computational model. Methods: We present a computational model with different channels and receptors, including sodium, potassium, calcium, NMDARs, and AMPARs, which can produce burst-type action potentials. In the simulations, by changing the delayed rectifying potassium conductance bifurcation diagram is calculated. Conclusion: Results show that for a specific range of potassium conductance, a chaotic regime emerges in produced action potentials. These chaotic oscillations may play a role in inducing abnormal memories.

scholarly journals Assessing the utility of MAGNETO to control neuronal excitability in the somatosensory cortex

2019 ◽  
Author(s):  
Koen Kole ◽  
Yiping Zhang ◽  
Eric J. R. Jansen ◽  
Terence Brouns ◽  
Ate Bijlsma ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Action Potentials ◽  
Magnetic Stimulation ◽  
Neuronal Excitability ◽  
Neural Interfaces ◽  
Intracellular Recordings ◽  
Membrane Excitability ◽  
Freely Moving ◽  
The Brain

Magnetic neuromodulation has outstanding promise for the development of novel neural interfaces without direct physical intervention with the brain. Here we tested the utility of Magneto in the adult somatosensory cortex by performing whole-cell intracellular recordings in vitro and extracellular recordings in freely moving mice. Results show that magnetic stimulation does not alter subthreshold membrane excitability or contribute to the generation of action potentials in virally transduced neurons expressing Magneto.

scholarly journals Impact of Membrane Resistance on Width and Amplitude of Spikes in Different Injected Currents in One Spiking Neural Model

2021 ◽  
Vol 20 ◽  
pp. 196-202
Author(s):  
Shima Pilehvari ◽  
Lei Zhang ◽  
Rene V. Mayorga
Keyword(s):  
Action Potentials ◽  
Linear Time ◽  
Neural Model ◽  
Membrane Resistance ◽  
Electrical Parameters ◽  
Four Dimensions ◽  
Numerical Investigations ◽  
Current Threshold ◽  
The Impact ◽  
The Brain

Neurons in the brain as the elementary processing units and nervous system play a key role. If a neuron gets a proper stimulus, it produces action potentials (spikes) that are transferred along its axon. Reaching the end of the neuron, other neurons or muscle cells may be activated [1]. The effect of neural morphology along with thickness of dendrites and passive electrical parameters on the spikes width and amplitude can be investigated by analytical and numerical investigations of spiking models. The impact of mentioned proper stimulus may be degraded by passing time. In this paper, it is tried to add the effective parameter ’membrane resistance’ in well-known Hodgkin-Huxley model with four dimensions to compare several outputs due to changing resistance and various injected current. The goal of this paper has been to measure spikes changes or even how to determine current threshold when resistance is not constant (non-linear time dependant) result of different factors.

scholarly journals Molecular and Cellular Impact of Inflammatory Extracellular Vesicles (EVs) Derived from M1 and M2 Macrophages on Neural Action Potentials

2020 ◽  
Vol 10 (7) ◽  
pp. 424
Author(s):  
Sarah Vakili ◽  
Taha Mohseni Ahooyi ◽  
Shadan S. Yarandi ◽  
Martina Donadoni ◽  
Jay Rappaport ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Immune Cells ◽  
Action Potentials ◽  
M2 Macrophage ◽  
M2 Macrophages ◽  
Neuronal Functions ◽  
The Brain ◽  
Macrophage Subtypes ◽  
M1 And M2 Macrophages

Several factors can contribute to neuroinflammatory disorders, such as cytokine and chemokines that are produced and released from peripherally derived immune cells or from locally activated cells such as microglia and perivascular macrophages in the brain. The primary function of these cells is to clear inflammation; however, following inflammation, circulating monocytes are recruited to the central nervous system (CNS). Monocyte-derived macrophages in the CNS play pivotal roles in mediating neuroinflammatory responses. Macrophages are heterogeneous both in normal and in pathological conditions due to their plasticity, and they are classified in two main subsets, classically activated (M1) or alternatively activated (M2). There is accumulating evidence suggesting that extracellular vesicles (EVs) released from activated immune cells may play crucial roles in mediating inflammation. However, a possible role of EVs released from immune cells such as M1 and M2 macrophages on neuronal functions in the brain is not known. In order to investigate the molecular and cellular impacts of macrophages and EVs released from macrophage subtypes on neuronal functions, we used a recently established in vitro M1 and M2 macrophage culture model and isolated and characterized EVs from these macrophage subtypes, treated primary neurons with M1 or M2 EVs, and analyzed the extracellular action potentials of neurons with microelectrode array studies (MEA). Our results introduce evidence on the interfering role of inflammatory EVs released from macrophages in interneuronal signal transmission processes, with implications in the pathogenesis of neuroinflammatory diseases induced by a variety of inflammatory insults.

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