Myelin increases resistance across the cell membrane

AI Thread Summary
Myelin significantly enhances the speed of action potential transmission by increasing membrane resistance and decreasing capacitance. The reduction in capacitance occurs because myelin wraps around the axon multiple times, effectively placing capacitors in series, which lowers the overall capacitance. This allows for faster signal propagation, as action potentials are generated only at the nodes of Ranvier, where voltage-gated channels are concentrated. In contrast, demyelination can severely impair signal transmission, as the action potential cannot effectively jump between nodes without sufficient voltage-gated channels. Overall, myelin plays a crucial role in optimizing neuronal communication speed and efficiency.
  • #51


somasimple said:
If you reject Cm then you reject the whole theory...

Yes, and no. I think the decrease in Cm is required to offset the increase in Rm, so that the time constant remains the same. There are no outright contradictions between what I'm saying and the standard explanations. BUT there are enough differences in emphasis that I should look at the equations carefully and see whether the apparent lack of contradiction between the two explanations is due to a real similarity in the underlying mathematics, or just due to chance. But those details are not in Koch's book.

somasimple said:
I do... but I can't say anything on this site without being thunder lightened by modos.

Maybe to be careful, you should say "at least one modo (singular)". :smile:
 
Biology news on Phys.org
  • #52


atyy said:
Maybe to be careful, you should say "at least one modo (singular)". :smile:
I can't. It is out of my capacitance and resistance.:smile:
 
  • #53


somasimple said:
I can't. It is out of my capacitance and resistance.:smile:
:smile::smile::smile:
 
  • #54


atyy said:
Order of magnitude means correct to within a factor of <10 (I usually think ~3-4)
with the function:
The minimal value found with 250 turns is a Time Constant that is multiplied by a factor 20.
the worst is... 1250
 

Attachments

  • tau_variation_1024.png
    tau_variation_1024.png
    9.8 KB · Views: 625
Last edited:

Similar threads

Back
Top