Sommer, P.; Zeldenrust, F.; Jedlicka, P.; Bird, A. D.; Triesch, J.

Neurons exhibit an impressive diversity. Even within the same cell type, firing rates can vary by several orders of magnitude, and key parameters ---- including resting membrane potential, membrane resistance, and synaptic inputs --- differ substantially across neurons. It is presently unclear if this diversity reflects independent sources of variation such as a noisy expression of different ion channels in a neuron's membrane, or if there is any hidden structure in this large diversity of neuronal parameters and the neuron's resulting behavior. One potential source of such structure is evolutionary pressure that has sculpted brains to work in an energy-efficient manner. Here, we use computational modeling to identify a manifold within a neuron's parameter space permitting energy-efficient signaling. Neurons whose parameters lie on this manifold represent degenerate solutions to the problem of energy-efficient signaling. We confirm that neuronal features in different sensory brain areas indeed fall on such a manifold and that food restriction induces systematic shifts of neuronal parameters on this manifold. Our results reveal that the large diversity of neuronal properties is tightly regulated to ensure energy-efficient signaling in the presence of different computational tasks and context.