Questions tagged [electrophysiology]
The study of the electrical properties of biological cells and tissues.
14
questions
32
votes
3
answers
35k
views
Why is saltatory conduction in myelinated axons faster than continuous conduction in unmyelinated axons?
How does spacing apart sodium and potassium channels allow the action potential to travel faster down the axon? This is the reason always cited for saltatory conduction and myelination, but my mental ...
- 323
5
votes
1
answer
2k
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.
$$\text{OUT:IN}$$
$$\text{K}^+ (1:20)$$
$$\text{Cl}^- (11.5:1)$$
$$\text{Ca}^{2+} (10000:1)$$
$$\text{Na}^+...
- 2,060
9
votes
1
answer
3k
views
What keeps the resting potential of neurons constant at -70 mV?
I know the sodium-potassium pump pumps out 3 Na+ ions and pumps in 2 K+ ions per reaction so the negative charge in the axon increases. However, once the voltage (difference of charge inside and ...
- 1,517
10
votes
2
answers
27k
views
How is membrane capacitance related to the increased speed of saltatory conduction?
Here is the original question which inspired my question. As explained by the answers there, the reason saltatory conduction in myelinated neurons is faster than non-myelinated conduction is because ...
- 4,669
6
votes
1
answer
2k
views
Why do larger diameter myelinated axons have greater conduction velocities than small diameter myelinated axons?
A canonical statement I have frequently read is that "large diameter axons conduct action potentials at faster velocities than small diameter axons". After recently learning the effect of increased ...
- 375
1
vote
0
answers
138
views
Are large cell bodies of neurons harder to depolarize than small cell bodies of neurons?
In order for the axon to initiate an action potential, we know that the axon initial segment must be brought to threshold. So my question is as follows:
Say we have the minimum charge input, "X", ...
- 375
8
votes
2
answers
557
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 (...
- 639
7
votes
1
answer
6k
views
Why do neurons have a negative resting potential?
Neurons expend the majority of their energy powering ion pumps to maintain the chemical gradients that power their electrical activity. To have a negative resting potential, neurons leak potassium ...
- 658
5
votes
1
answer
98
views
At What Rate Do Ions Leak Out of a Plasma Membrane Segment That Has No Ion Channels?
In reading about the purpose of myelin during action potential propagation, I came across a point of confusion.
From what I understand, one of the primary "benefits" of myelin is that it aids in ...
- 375
5
votes
0
answers
133
views
How to measure Na/K channel activation at the membrane level?
Assume that there are two different signals occurring on the ECG - during depolarization and repolarization in the standard ECG.
I was advised not to use the standard ECG in measuring the exact ...
- 5,149
4
votes
1
answer
180
views
Do electric eels produce current as they just move about, and how/why?
https://www.youtube.com/watch?v=y9wktSQdyaE
This video demonstrates how an electric eel can supposedly produce up to 800 watts, and power a Christmas tree, which is very topical (a late Merry ...
- 273
4
votes
1
answer
1k
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 ...
- 712
4
votes
1
answer
864
views
Mechanisms of extracellular stimulation of neurons
When stimulating a group of neurons with an electrode, let's say we put it in a region that contains axons, what is the mechanism by which the axons are stimulated?
I've been told electrodes (...
- 143
2
votes
0
answers
162
views
Living potato clock? [duplicate]
Could a potato stay alive and power a clock while growing in the ground?
I know how a potato clock works as a electrochemical cell and involves chemistry, but I am only interested in a growing ...
- 1