Yep, I think so too. Nothing in my reply to you right now may depend on the DNA directly as DNA is too slow; it has to use the already existing proteins which we already know we need to scan. Ditto for the 'long term memory'; long term memory write and recall cannot rely on this if you remember something from 3 minutes ago (which is still 'long term').

So, from a scan that does not read DNA we would have sufficient information to at least create the brain emulation that can write this reply; we may also need to figure out how retrotransposons work in the neurons to make the simulation accurate long-term (the emulation might otherwise end up with some kind of learning disability, potentially quite severe if the emulated brain can't retain long term memories beyond the span of several hours).

But I do not think we would absolutely have to find out a way to read the DNA off each neuron when making the scan. It would suffice to infer everything from the copy in the proteins. (however if we find a way to read dna of every neuron, it might be that we could use it instead of reading the proteins themselves accurately).

Are you thinking about the immune system? If not I'd be interested in knowing more.

The system that makes neuron not connect to itself.

edit: that's what i mean