Activity-driven local ATP synthesis is required for synaptic function

Cell. 2014 Feb 13;156(4):825-35. doi: 10.1016/j.cell.2013.12.042.

Abstract

Cognitive function is tightly related to metabolic state, but the locus of this control is not well understood. Synapses are thought to present large ATP demands; however, it is unclear how fuel availability and electrical activity impact synaptic ATP levels and how ATP availability controls synaptic function. We developed a quantitative genetically encoded optical reporter of presynaptic ATP, Syn-ATP, and find that electrical activity imposes large metabolic demands that are met via activity-driven control of both glycolysis and mitochondrial function. We discovered that the primary source of activity-driven metabolic demand is the synaptic vesicle cycle. In metabolically intact synapses, activity-driven ATP synthesis is well matched to the energetic needs of synaptic function, which, at steady state, results in ∼10(6) free ATPs per nerve terminal. Despite this large reservoir of ATP, we find that several key aspects of presynaptic function are severely impaired following even brief interruptions in activity-stimulated ATP synthesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Animals
  • Mitochondria / metabolism*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Presynaptic Terminals / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Synapses / metabolism*
  • Synaptic Vesicles / metabolism

Substances

  • Nerve Tissue Proteins
  • Unc13h1 protein, rat
  • Adenosine Triphosphate