Differential energetic profile of signal processing in central vestibular neurons.

Background: Energetic aspects of neuronal activity have become a major focus of interest given the fact that the brain among all organs dominates the oxygen consumption. At variance with the importance of neuroenergetics, the knowledge about how electrical activity and metabolism is correlated in defined neuronal populations is still rather scarce. Results: We have estimated the ATP consumption in the two physiologically well characterized populations of frog central vestibular neurons, with tonic and phasic firing patterns, respectively. These two distinct groups of neurons jointly process head/body movements detected by semicircular canal and otolith organs in the inner ear. The ATP consumption for maintenance of the resting membrane potential (V Conclusion: Despite the sparse production of action potentials by phasic vestibular neurons, the computation by this neuronal type dominates the ATP expense for processing head/body movements, which might have contributed to the late evolutionary arrival of this central neuronal element, dedicated to the encoding of highly dynamic motion profiles.