http://www.scientificamerican.com/article.cfm?id=marijuana-reveals-memory-mechanism
I wonder what the implications are for brain preservation and whole brain emulation? If glial cells are important, then saving and emulating the neurons alone probably won't be enough.
I know next to nothing of biology, but I would naïvely expect the structure of the ATP, ADP, AMP, etc. to be fixed across all organisms with mitochondria. Shouldn't copying errors or variations that produce something other than ATP in place of ATP kill any eukaryote, let alone a human? Perhaps you mean variations to ATP synthase?
I know little biology, too. I can check back with the person who told me that-- the way I understood it was that there are slightly different versions of ATP, some of which are more efficient, but all of which work.