It has been proposed that ThTP has a specific role in nerve excitability, but this has never been confirmed and recent results suggest that ThTP probably plays a role in cell energy metabolism. Low or absent levels of thiamine triphosphate have been found in Leighs disease. 
In E. coli, ThTP is accumulated in the presence of glucose during amino acid starvation.  On the other hand, suppression of the carbon source leads to the accumulation, of adenosine thiamine triphosphate (AThTP).