Jump to content

  • Log in with Facebook Log in with Twitter Log in with Windows Live Log In with Google      Sign In   
  • Create Account

Submit your paper to J Biol Methods today!
- - - - -

Conceptual problem on myelination and conductance

  • Please log in to reply
No replies to this topic

#1 litos



  • Active Members
  • Pip
  • 10 posts

Posted 11 August 2010 - 07:35 AM


I know this is resourceful and sage forum so I hope to clarify my doubts once for all ;)

I've recently started to do some research on electrophysiology and the concept of myelination and saltatory conduction still baffles me.

Needless to say, I know perfectly the mechanics behind AP conduction in non-myelinated fibers. I also know how myelin seems to speed up the propagation velocity of the AP but here come my doubts:

- Myelin increases transmembrane resistance, thus increasing the "length constant" (i.e. avoids the weakening of the passive currents that spread along the axon).

- Myelin decreases the capacitance of the internodal regions, reducing the "time constant" and enabling a faster depolarization of the nodal regions. But ¿WHY? Is not the capacitance of the nodal regions the same as in a "normal" (non myelinated) axons? If the internodal regions are "sealed" (myelin is an insulator), and no AP is generated here, what's the role of a lowered capacitance in this zone?

Note: I understand that a lowered capacitance means that fewer charges need to be moved in order to produce a given potential difference.

I'd be very grateful If anyone could help me with this complicated topic.

Thanks in advance,


Home - About - Terms of Service - Privacy - Contact Us

©1999-2013 Protocol Online, All rights reserved.