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Ca2+/cAMP-sensitive covariation of IA and IH voltage dependences tunes rebound firing in dopaminergic neurons
journal contribution
posted on 2023-05-17, 13:55 authored by Amendola, J, Adele WoodhouseAdele Woodhouse, Martin-Eauclaire, M-F, Goaillard, J-MThe level of expression of ion channels has been demonstrated to vary over a threefold to fourfold range from neuron to neuron, although the expression of distinct channels may be strongly correlated in the same neurons. We demonstrate that variability and covariation also apply to the biophysical properties of ion channels. We show that, in rat substantia nigra pars compacta dopaminergic neurons, the voltage dependences of the A-type (I(A)) and H-type (I(H)) currents exhibit a high degree of cell-to-cell variability, although they are strongly correlated in these cells. Our data also demonstrate that this cell-to-cell covariability of voltage dependences is sensitive to cytosolic cAMP and calcium levels. Finally, using dynamic clamp, we demonstrate that covarying I(A) and I(H) voltage dependences increases the dynamic range of rebound firing while covarying their amplitudes has a homeostatic effect on rebound firing. We propose that the covariation of voltage dependences of ion channels represents a flexible and energy-efficient way of tuning firing in neurons.
History
Publication title
Journal of NeuroscienceVolume
32Issue
6Pagination
2166-2181ISSN
0270-6474Department/School
Tasmanian School of MedicinePublisher
Society for NeurosciencePlace of publication
1121 14th St, NW, Washington DC, USARights statement
Copyright 2012 the authorsRepository Status
- Restricted