Human nerve impulses travel at ballpark of 1e-7 c though, so limits of physics let you keep the relative signaling speed constant while making the system betwee

Human nerve impulses travel at ballpark of 1e-7 c though, so limits of physics let you keep the relative signaling speed constant while making the system between enormously larger in radius. And the volume (and hence number of neurons) of course grows approximately as a cube of radius!