Cost of auditory sharpness: Model-Based estimate of energy use by auditory brainstem "octopus" neurons.

Autor: Zhukov OA; Department of Biophysics, Biological faculty, Lomonosov Moscow State University, Leninskie Gory 1/12, Moscow 119234, Russia., Kazakova TA; Department of Biophysics, Biological faculty, Lomonosov Moscow State University, Leninskie Gory 1/12, Moscow 119234, Russia., Maksimov GV; Department of Biophysics, Biological faculty, Lomonosov Moscow State University, Leninskie Gory 1/12, Moscow 119234, Russia., Brazhe AR; Department of Biophysics, Biological faculty, Lomonosov Moscow State University, Leninskie Gory 1/12, Moscow 119234, Russia; Department of Molecular Neurobiology, Institute of Bioorganic Chemistry RAS, Miklukho-Maklay 16/10, Moscow 117997, Russia. Electronic address: brazhe@biophys.msu.ru.
Jazyk: angličtina
Zdroj: Journal of theoretical biology [J Theor Biol] 2019 May 21; Vol. 469, pp. 137-147. Date of Electronic Publication: 2019 Mar 02.
DOI: 10.1016/j.jtbi.2019.01.043
Abstrakt: Octopus cells (OCs) of the mammalian auditory brainstem precisely encode timing of fast transient sounds and tone onsets. Sharp temporal fidelity of OCs relies on low resting membrane resistance, which suggests high energy expenditure on maintaining ion gradients across plasma membrane. We provide a model-based estimate of energy consumption in resting and spiking OCs. Our results predict that a resting OC consumes up to 2.6 × 10 9  ATP molecules (ATPs) per second which remarkably exceeds energy consumption of other CNS neurons. Glucose usage by all OCs in the rat is nevertheless low due to their low number. Major part of the OCs energy use results from the ion mechanisms providing for the low membrane resistance: hyperpolarization-activated mixed cation conductance and low-voltage activated K + -conductance. Spatially ordered synapses-a feature of the OCs allowing them to compensate for asynchrony of the synaptic input-brings only a 12% energy saving to OCs excitability cost. Only 13% of total OC energy used for an AP generation (1.5 × 10 7  ATPs) is associated with the AP generation in the axon initial segment, 64%-with synaptic currents processing and 23%-with keeping resting potential.
(Copyright © 2019 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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