Date: 25th, September(thu) 15:00-17:00
PlaceFRoom Ew-305, E Block,IIS, The University of Tokyo 
SpeakerFDr. Renaud Jolivet(University of Zurich@Institute of Pharmacology and Toxicology)
TitleFDeciphering neuron-glia compartmentalization in cortical energy metabolism

Abstract:
Glucose is the main energy substrate in the adult brain under normal
conditions. Over the last years, evidence has accumulated indicating that
lactate glycolytically produced from glucose in astrocytes could be
oxidatively metabolized in neurons. The significance and possible roles of
this so-called astrocyte-neuron metabolic shuttle are still a much debated
issue. I will briefly introduce this question within the larger framework of
cortical energy metabolism and show how it can be addressed using different
types of mathematical approaches. I will first show how an
activity-dependent energy budget can be computed for cortical matter in a
top-down fashion, starting from the amount of energy substrates consumed by
the brain and progressively segmenting energy production in glial vs.
neuronal components and signaling vs. non-signaling components. This
approach also yields an estimate for the compartmentalization of glucose and
oxygen utilization between neurons and astrocytes. I will then show that
these results support the presence of a shuttle of carbons from astrocytes
to neurons, the amplitude of which is correlated to the activity-level
within the tissue (specifically to the cycling of neurotransmitters).
Second, I will present a detailed biophysical model of astrocyte-neuron
metabolic interactions. I will show that constraints derived in the first
part of my talk impose a lactate shuttle from astrocytes to neurons. I will
also show that the biophysical model is consistent and to some extent
predicts the dynamics of several important markers of energy metabolism.
Finally, I will discuss the possible roles of this neuron-astrocyte coupling
as well as future work.