Neuromodulators, not activity, control coordinated expression of ionic currents

Document Type

Article

Publication Date

8-8-2007

Abstract

Electrical activity in identical neurons across individuals is often remarkably similar and stable over long periods. However, the ionic currents that determine the electrical activity of these neurons show wide animal-to-animal amplitude variability. This seemingly random variability of individual current amplitudes may obscure mechanisms that globally reduce variability and that contribute to the generation of similar neuronal output. One such mechanism could be the coordinated regulation of ionic current expression. Studying identified neurons of the Cancer borealis pyloric network, we discovered that the removal of neuromodulatory input to this network (decentralization) was accompanied by the loss of the coordinated regulation of ionic current levels. Additionally, decentralization induced large changes in the levels of several ionic currents. The loss of coregulation and the changes in current levels were prevented by continuous exogenous application of proctolin, an endogenous neuromodulatory peptide, to the pyloric network. This peptide does not exert fast regulatory actions on any of the currents affected by decentralization. We conclude that neuromodulatory inputs to the pyloric network have a novel role in the regulation of ionic current expression. They can control, over the long term, the coordinated expression of multiple voltage-gated ionic currents that they do not acutely modulate. Our results suggest that current coregulation places constraints on neuronal intrinsic plasticity and the ability of a network to respond to perturbations. The loss of conductance coregulation may be a mechanism to facilitate the recovery of function. Copyright © 2007 Society for Neuroscience.

Identifier

34547922787 (Scopus)

Publication Title

Journal of Neuroscience

External Full Text Location

https://doi.org/10.1523/JNEUROSCI.1274-07.2007

e-ISSN

02706474

ISSN

02706474

PubMed ID

17687048

First Page

8709

Last Page

8718

Issue

32

Volume

27

Grant

R01MH064711

Fund Ref

National Institute of Mental Health

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