Yes. Just because something is necessary for the brain to operate doesn't mean specific versions need to be preserved rather than some generic version. It is necessary for you to have a skull to think and live, but I don't think many people expect the individual bumps and indentations to need to be preserved for a faithful upload...
On the other hand, people probably have slightly different versions of glial cells, and which model of glial cells you have might have some effect on your personality and intelligence.
Actually, it's probably not just one model per person. I've been told that there's more than one sort of ATP (copying errors and variations), even inside one person, and if ATP isn't universally identical, then you can't expect anything else to be.
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.