Figure 1.

Predicted signaling energy use for cerebral cortex. (A) Energy distribution among subcellular processes for the cerebral cortex. Resting potentials account for ∼20% of the total energy use, action potentials 21%, and synaptic processes 59% (including postsynaptic receptors (50%), neurotransmitter recycling (4%), and presynaptic Ca²⁺ entry and vesicle cycling (5%)). (B) As panel A, but including non-signaling energy use, assumed to be 6.81 × 10²² ATP/s/m³, that is, 1/3 of the neuronal signaling energy, so that housekeeping tasks are assumed to account for 25% of the total energy use. On this basis, resting potentials use 15%, action potentials 16%, and synaptic processes 44% of the total energy use.