1 research outputs found
Energy demands of diverse spiking cells from the neocortex, hippocampus, and thalamus
It has long been known that neurons in the brain are not physiologically
homogeneous. In response to current stimulus, they can fire several distinct
patterns of action potentials that are associated with different physiological
classes ranging from regular-spiking cells, fast-spiking cells, intrinsically
bursting cells, and low-threshold cells. In this work we show that the high
degree of variability in firing characteristics of action potentials among
these cells is accompanied with a significant variability in the energy demands
required to restore the concentration gradients after an action potential. The
values of the metabolic energy were calculated for a wide range of cell
temperatures and stimulus intensities following two different approaches. The
first one is based on the amount of Na+ load crossing the membrane during a
single action potential, while the second one focuses on the electrochemical
energy functions deduced from the dynamics of the computational neuron models.
The results show that the thalamocortical relay neuron is the most
energy-efficient cell consuming between 7 and 18 nJ/cm2 for each spike
generated, while both the regular and fast spiking cells from somatosensory
cortex and the intrinsically-bursting cell from a cat visual cortex are the
least energy-efficient, and can consume up to 100 nJ/cm2 per spike. The lowest
values of these energy demands were achieved at higher temperatures and high
external stimuli