We have also discussed this extensively but I can't find the thread. Infact I think you already started a thread about this once no? Heh.

Anyway its most likely involved in sensory perception. It appears dmt is an endogenous ligand of the trace amine receptors. It also binds to 5-HT receptors but that might not be its main role. Anyway see the scientific article section for some papers that discuss this or look deeper on this site becuase we have discussed it a lot.