The study of the electrical properties of biological cells and tissues.

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What will happen to a neuron if I suddenly remove the pump but not the leaky Na+ and K+ channels?

K+ is more abundant inside the cell and thus has a propensity to move outwards. It has an equilibrium potential of -80 mV. Na+ is more abundant extracellularly and thus has a propensity to move ...
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5 views

At which voltage will the conductance decrease due to the narrow pore in a voltage-gated potassium channel?

If you have a voltage-gated potassium channel that do not inactivate, at which voltage would you see decrease in ion conductance related to the narrow path in the pore? With that said I know that in ...
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18 views

Potential homogeneity across cell membrane

During respiration, individual bacteria (and mitocondria) produce a relatively large potential difference (∼100 mV) between the inside and outside, using energy to pump $H^+$ out of the cell to the ...
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28 views

Understanding the configuration of channels in the 10-20 EEG montage

In a typical 10-20 system there are 21 electrodes placed on the scalp. However, this does not mean there are 21 distinct "channels" or voltage sources. I've heard that some of these electrodes are ...
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96 views

What signal processors comprise an Event-Related Potential system for EEG?

So my 30,000 ft. understanding of the EEG signal processing data flow is: Capture raw EEG data ("raw waveforms") Run these raw waveforms through a Signal Processing Framework that consists of 1+ ...
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994 views

Why is Fast Fourier Transform applied to raw EEG data?

I am trying to understand why Fast Fourier Transform (FFT) is used in the analysis of raw EEG channel data. My understanding (at the 30,000 ft view) is that FFT decomposes linear differential ...
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19 views

Analysing the ERP (Event-Related Potential from EEG recordings) in terms of the P-300 wave

I am trying to understand how to analyze ERP (Event-Related Potentials) from EEG recordings in focus on P-300 waves. I have come up with a few questions which I hope you might be able to help with: ...
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26 views

Why is active transport needed in repolarization?

During the repolarization phase of an action potential, the potassium ions diffuse out of the cell, and active transport begins. What I do not understand is why active transport is needed when the ...
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32 views

Article or answer to whether “blood volume pressure” and “electrodermal activity” have any correlation to stress and or feelings overall

As the title suggests, I would like some help finding if there is any correlation between between blood volume pressure and electrodermal activity? The paper I'm writing is about measuring stress and ...
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24 views

Is there an equivalent to a refresh rate for the brain and consciousness?

Computers have a clock rate that synchronizes their processors. In spite of tempting analogies, the brain is clearly not simply an organic computer. It is constantly changing, rewiring and pruning its ...
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1answer
12 views

Why are local field potentials generally band-pass filtered?

I was wondering what the rationale was behind low-pass or band-pass filtering in local field potential measurements? It seems to me that we could potentially filter out potentially valuable ...
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62 views

How's the membrane potential restored to resting state after hyper polarisation?

I have known for so long that Na+/ K+ pump restores the membrane potential. But as it pumps in 2 K+ for every 3+ Na+ moving out how can it make the membrane potential less negative when the net result ...
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100 views

Why does the intensity of an action potential once generated at the trigger zone remain undistured throught the axon?

What causes this consistency? I read the previously asked questions on this site none of them carry an answer to this question.
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72 views

What is the direction of current flow in myelinated nerve cells?

Is it correct to say electric current flows through the extracellular space, or cytosol of a nerve fiber during impulse conduction? I know that an impulse is actually a change of membrane potential ...
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37 views

How are physiological reversal potentials (or ion concentrations) of neurons measured?

Patch clamp electrophysiology experiments typically use an intracellular solution that mimics the ionic concentrations of neuronal cytosol. At the same time, the extracellular solution is meant to ...
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58 views

Do repetitive movements on EEGs show up as discernible patterns?

Here is a typical EEG reading: If I am connected to an EEG, and am sitting perfectly still, and then begin doing some repetitive motion, say, 10,000 times, will we see discernible patterns emerge ...
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1answer
94 views

What are wave frequencies in the EEG?

Here is a typical EEG reading: I understand that each row corresponds to the signal read between two sensors on a standard 10-20 (or 10-5) distribution setup (e.g. ...
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62 views

What is the lower temperature limit for ion channels function?

What is the cold-block temperature of ion channels? (not of nerves or axons)
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29 views

Efficacy of the 10-20 montage for EEG

I am trying to better understand the relationship between the placement of EEG electrodes and the quality of the "brainwave" signals they produce. There is the standard 10-20 system which has me ...
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1answer
79 views

What are the highest and lowest amplitude values in ECG for humans?

I'm currently trying to parse the records captured from an ECG device and display them on a mobile application. I am wondering what the highest and lowest possible amplitude values for ECGs are in ...
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40 views

What physical or mental actions can be picked up by EEGs?

There certainly seem to be a lot of gadgets and gizmos leveraging EEG technologies to the control of devices. This makes me wonder: what intentions/thoughts can be captured by EEG technology, and ...
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23 views

Effects of pH vs membrane potential within a cell? [closed]

How are these two concepts related? Does changing each result in the same effects? As in: what kind of reactions/processes would be affected if we changed the pH within a cell? Would the results ...
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29 views

Relationship between body size and damage done by electricity

We all know that if a person gets stunned by a 2000 volt stun gun, he/she may be knocked unconscious, but he/she is still alive and apparently no damage done on his/her body. But what could happen if ...
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50 views

Why is stimulation of nerve tissue with a negative pulse called “cathodic” stimulation?

By definition, the cathode is defined as the terminal through which current exits a polarized device. But in the context of neuromodulation, such as spinal cord stimulation, deep brain stimulation, ...
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34 views

How are cardiac cells stimulated by an action potential?

Why, and how, does the action potential of one cell in the heart stimulate an action potential in the next cell? I'm interested in an answer with citation.
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16 views

EMG recording and muscular contraction

In many form of peripheral neuropathies the excitability of some neurons is changed and their conduction velocities are consequently altered.What are the effects that this might have on an EMG ...
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10 views

ECG cardiac monitoring

How is the signal observed from electrode and electrode impedance is affected if we clean one of the pair of Ag/AgCl cardiac electrode by scraping it with steel wool until it was shiny and bright
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204 views

Why does depolarisation by high intracellular K+ trigger calcium channels opening?

I have learnt that in pancreatic beta cells, glucose being metabolised in the cell causes a high ATP level, which triggers ATP-dependent potassium channels to close. This means that potassium can't ...
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1answer
24 views

How can I interface cAMP signal or membrane potential from slime mold to an electrode?

I am very much interested in measuring cAMP (cyclic adenosine mono phosphate) signal and membrane potential from amoeba. Since I want to try this as a hobby, what are the basic steps I must do to view ...
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1answer
107 views

Can an electrocardiogram be recorded with a single electrode?

Is it possible to do an electrocardiogram with one electrode? Or is it neccesary to have multiple electrodes? I do not understand much about EKG, so I am sorry if this question sounds naive.
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212 views

Doubling the concentration of extracellular calcium hyperpolarizes a neuron. Why?

I was doing some back of the envelope calculations to try to answer this question in more mathematical terms. Essentially the question states: Why does increasing the extracellular potassium ...
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121 views

If the average resting potential of a neuron is -70 mV, why is there such a high ratio of potassium ions inside relative to out?

My bio teacher was discussing the ratios of different ions inside versus outside the cell. $$\text{OUT:IN}$$ $$\text{K}^+ (1:20)$$ $$\text{Cl}^- (11.5:1)$$ $$\text{Ca}^{2+} (10000:1)$$ ...
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375 views

Why is Electrical Cardioversion contraindicated in AF and Digitalis Poisoning?

I am thinking why electrical cardioversion is contraindicated in atrial fibrillation with digitalis toxicity/poisoning. Cardiac digitalis is also called digoxin and cardiac glycoside. It is ...
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1answer
36 views

Is missing Q wave characteristic for Wolff-Parkinson-White Syndrome?

No my study books says about that no Q waves in WPW syndrome. They are about wide QRS complex often however. I heard today that the characteristic property of WPW is often a missing Q wave, like here ...
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37 views

classical conditioning paradigm for hippocampal learning

I wanted to know what a suitable classical conditioning experiment would be to analyze learning and memory capabilities in rodent models with respect to hippocampal long-term potentiation. For ...
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158 views

Explanation of ECG in MI using an electrostatic model

I found a paper presenting an electrostatic model to explain the ECG recorded in various leads. This model essentially calls for considering the depolarization wavefront to be the major contributing ...
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399 views

Mechanism behind negative conductance of ion channels

I am struggling to understand negative conductance shown on I-V curves on ion channels. Mechanistically, negative conductance means that inward (or outward) current increases when voltage across ...
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1answer
281 views

What is the reason behind high resting membrane potential of pacemaker cells?

Pacemaker cells have high resting membrane potentials of -50 to -40 mV, whereas normal cells have their resting membrane potential around -70 mV. Which ions, and what kind of channels are responsible ...
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258 views

How to analyse an ECG?

I have a project about extracting features from a homemade ECG. I need the PQRST points from the signal of the heart beat. The ECG I'm using has 3 electrodes that attach to the chest. The problem is ...
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1answer
100 views

Software recommendation for protein in electric field modeling? [closed]

I'd appreciate a suggestion for software to compare models of two proteins in an alternating electric field. The more detail, or perhaps direction towards an existing and similar paper, the better. ...
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294 views

How does a microelectrode work?

On Wikipedia, the entire microelectrode page states only the following: A microelectrode is an electrode of very small size, used in electrophysiology for either recording of neural signals or ...
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192 views

Measuring a plant's electric activity any instructions where to place electrodes?

I would like to measure a plant's electric activity / voltage, I've looked online to find out where to place the electrodes and what type of electrodes to use but they seem to very wildly. Any ideas? ...
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155 views

Are Gram negative bacteria classified as such because of their negative membrane potential?

Does the membrane potential usually quoted for Gram negative bacteria (e.g., E. coli) refer to the potential across both membranes? - If yes, then does the potential fall more over the inner or outer ...
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184 views

Is there a biological neuron that spikes in response to hyperpolarizing currents?

As some background I've been building Electrophysiological models of neurons, and in the process stumbled upon a model, that in all respects is biologically plausible, but has a bizarre property I ...
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1answer
152 views

Similarity between a heart attack and a spasm

When someone is having a heart attack, could it be considered , in some situations, a spasm? Below, I have written how I believe the process may work. The heart is basically a muscle working ...
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36 views

Neural correlates of the function of the cardiovascular system?

Are there any known neural correlates of the function of the cardiovascular system? I'm looking for research results that use standard brain imaging techniques (e.g. electroencephalography, ...
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1answer
60 views

What equipment is needed to perform simple plant electrophysiology?

What is the minimum needed equipment to perform simple plant electrophysiology? I am looking for some simple experiments that I could run at home for learning. Ideally, I would transfer the skills to ...
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2answers
915 views

Action potential changes in low sodium concentrations but constant osmotic pressure

If I bathe a squid axon in a fluid that has high sodium concentration , why does the duration of action potential decrease compared to a control experiment in low sodium bath but maintained at the ...
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225 views

What does pain look like in wave form?

I am interested in understanding what "pain" and "hot/cold" look like, as far as waves signatures (signal processing) go. My general understanding of how pain (nociceptive pathways) and hot/cold ...
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89 views

Are Purkinje Action Potentials Neuronal and Cardiac?

I first thought that action potentials of His-bundle i.e. Purkinje fibers are Cardiac. However, I started to think that this is not enough. I think now that they are neuronal and cardiac. My ...