Neocortex saves energy by reducing coding precision during food scarcity.

Zahid Padamsey, Danai Katsanevaki, Nathalie Dupuy, Nathalie L Rochefort

Neuron 2022 Jan 19

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Information processing is energetically expensive. In the mammalian brain, it is unclear how information coding and energy use are regulated during food scarcity. Using whole-cell recordings and two-photon imaging in layer 2/3 mouse visual cortex, we found that food restriction reduced AMPA receptor conductance, reducing synaptic ATP use by 29%. Neuronal excitability was nonetheless preserved by a compensatory increase in input resistance and a depolarized resting potential. Consequently, neurons spiked at similar rates as controls but spent less ATP on underlying excitatory currents. This energy-saving strategy had a cost because it amplified the variability of visually-evoked subthreshold responses, leading to a 32% broadening of orientation tuning and impaired fine visual discrimination. This reduction in coding precision was associated with reduced levels of the fat mass-regulated hormone leptin and was restored by exogenous leptin supplementation. Our findings reveal that metabolic state dynamically regulates the energy spent on coding precision in neocortex. Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.

Citation

Zahid Padamsey, Danai Katsanevaki, Nathalie Dupuy, Nathalie L Rochefort. Neocortex saves energy by reducing coding precision during food scarcity. Neuron. 2022 Jan 19;110(2):280-296.e10