Jump to ContentJump to Main Navigation
Biophysics of ComputationInformation Processing in Single Neurons$
Users without a subscription are not able to see the full content.

Christof Koch

Print publication date: 1998

Print ISBN-13: 9780195104912

Published to Oxford Scholarship Online: November 2020

DOI: 10.1093/oso/9780195104912.001.0001

Show Summary Details
Page of

PRINTED FROM OXFORD SCHOLARSHIP ONLINE (oxford.universitypressscholarship.com). (c) Copyright Oxford University Press, 2021. All Rights Reserved. An individual user may print out a PDF of a single chapter of a monograph in OSO for personal use. date: 04 December 2021

Diffusion, Buffering, and Binding

Diffusion, Buffering, and Binding

Chapter:
(p.248) 11 Diffusion, Buffering, and Binding
Source:
Biophysics of Computation
Author(s):

Christof Koch

Publisher:
Oxford University Press
DOI:10.1093/oso/9780195139853.003.0017

In Chap. 9 we introduced calcium ions and alluded to their crucial role in regulating the day-to-day life of neurons. The dynamics of the free intracellular calcium is controlled by a number of physical and chemical processes, foremost among them diffusion and binding to a host of different proteins, which serve as calcium buffers and as calcium sensors or triggers. Whereas buffers simply bind Ca2+ above some critical concentration, releasing it back into the cytoplasm when [Ca2+]i has been reduced below this level, certain proteins— such as calmodulin—change their conformation when they bind with Ca2+ ions, thereby activating or modulating enzymes, ionic channels, or other proteins. The calcium concentration inside the cell not only determines the degree of activation of calcium-dependent potassium currents but—much more importantly—is relevant for determining the changes in structure expressed in synaptic plasticity. As discussed in Chap. 13, it is these changes that are thought to underlie learning. Given the relevance of second messenger molecules, such as Ca2+, IP3, cyclic AMP and others, for the processes underlying growth, sensory adaptation, and the establishment and maintenance of synaptic plasticity, it is crucial that we have some understanding of the role that diffusion and chemical kinetics play in governing the behavior of these substances. Today, we have unprecedented access to the spatio-temporal dynamics of intracellular calcium in individual neurons using fluorescent calcium dyes, such as fura-2 or fluo-3, in combination with confocal or two-photon microscopy in the visible or in the infrared spectrum (Tsien, 1988; Tank et al., 1988; Hernández-Cruz, Sala, and Adams, 1990; Ghosh and Greenberg, 1995).

Keywords:   Action potentials, Binding, Cable theory, Diffusion, Electrodiffusion equation, Forward binding rate, Glutamate, Hormones, Infinite cable

Oxford Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.

Please, subscribe or login to access full text content.

If you think you should have access to this title, please contact your librarian.

To troubleshoot, please check our FAQs , and if you can't find the answer there, please contact us .