Oh, they found out what anesthetics does. It stops the formation of microtubuals within cells. So, pretty much anything can be anesthetized. And it suggest microtubuals might play a role in cognition.
I don't really see why plants wouldn't have some rudimentary sense of themselves? I mean, it wouldn't be as detailed as what animals experience, but they're alive, so why not? Maybe that's a leap. But, so is assuming the inverse. Arguably, that's a bigger assumption; why one kingdom of life and not the other?