Axonal Na+ channels detect and transmit levels of input synchrony in local brain circuits

by Mickaël Zbili, Sylvain Rama, Pierre Yger, Yanis Inglebert, Norah Boumedine-Guignon, Laure Fronzaroli-Moliniere, Romain Brette, Michaël Russier, Dominique Debanne
Abstract:
Sensory processing requires mechanisms of fast coincidence detection to discriminate synchronous from asynchronous inputs. Spike threshold adaptation enables such a discrimination but is ineffective in transmitting this information to the network. We show here that presynaptic axonal sodium channels read and transmit precise levels of input synchrony to the postsynaptic cell by modulating the presynaptic action potential (AP) amplitude. As a consequence, synaptic transmission is facilitated at cortical synapses when the presynaptic spike is produced by synchronous inputs. Using dual soma-axon recordings, imaging, and modeling, we show that this facilitation results from enhanced AP amplitude in the axon due to minimized inactivation of axonal sodium channels. Quantifying local circuit activity and using network modeling, we found that spikes induced by synchronous inputs produced a larger effect on network activity than spikes induced by asynchronous inputs. Therefore, this input synchrony–dependent facilitation may constitute a powerful mechanism, regulating synaptic transmission at proximal synapses.
Reference:
Mickaël Zbili, Sylvain Rama, Pierre Yger, Yanis Inglebert, Norah Boumedine-Guignon, Laure Fronzaroli-Moliniere, Romain Brette, Michaël Russier, Dominique Debanne, 2020. Axonal Na+ channels detect and transmit levels of input synchrony in local brain circuits, Science Advances, volume 6.
Bibtex Entry:
@article{Zbili2020,
	title = {Axonal {Na}+ channels detect and transmit levels of input synchrony in local brain circuits},
	volume = {6},
	copyright = {Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.},
	issn = {2375-2548},
	url = {https://advances.sciencemag.org/content/6/19/eaay4313.full.pdf},
	doi = {10.1126/sciadv.aay4313},
	abstract = {Sensory processing requires mechanisms of fast coincidence detection to discriminate synchronous from asynchronous inputs. Spike threshold adaptation enables such a discrimination but is ineffective in transmitting this information to the network. We show here that presynaptic axonal sodium channels read and transmit precise levels of input synchrony to the postsynaptic cell by modulating the presynaptic action potential (AP) amplitude. As a consequence, synaptic transmission is facilitated at cortical synapses when the presynaptic spike is produced by synchronous inputs. Using dual soma-axon recordings, imaging, and modeling, we show that this facilitation results from enhanced AP amplitude in the axon due to minimized inactivation of axonal sodium channels. Quantifying local circuit activity and using network modeling, we found that spikes induced by synchronous inputs produced a larger effect on network activity than spikes induced by asynchronous inputs. Therefore, this input synchrony–dependent facilitation may constitute a powerful mechanism, regulating synaptic transmission at proximal synapses.},
	language = {en},
	number = {19},
	journal = {Science Advances},
	author = {Zbili, Mickaël and Rama, Sylvain and Yger, Pierre and Inglebert, Yanis and Boumedine-Guignon, Norah and Fronzaroli-Moliniere, Laure and Brette, Romain and Russier, Michaël and Debanne, Dominique},
	month = may,
	year = {2020},
	pages = {eaay4313}
}