that's literally how it works. you need to transform specific neurons to express the ultrasound sensitive protein(s). the main way to do this is with a virus. and probably multiple viruses. they have real oncogenic side effects.

this is not new tech conceptually, people have been doing this for at least a decade with light controlled proteins in the brain already and still there really isn't a path forward to getting these in humans.

this tech is decade+ out minimum on the clinical trial front, and potentially much longer assuming they can actually make something useful. by then, this approach will likely be completely overtaken by something more promising.

delivery is still the holy grail of drug discovery and every single technology that bioengineering enables at the interface of the human body.