Special visceral motor neurons, also called "branchial motor neurons", which directly innervate branchial muscles (that motorize the gills in fish and the face and neck in land vertebrates).
It's another thing entirely to build that model and then motorize it so it spins like the computer-generated version of the castle seen in the show's epic opening credits.
The simple solution for the problem of solar cells not absorbing oblique sun rays would be to motorize the panels to follow the sun and the problem is solved.
Most enthusiasts use commercially available slot cars (often modified for better performance), others motorize static models, and some scratch-build, creating their own mechanisms and bodies from basic parts and materials.
