Weight training is as much neurological stimulation as it is muscular. In fact, most of the fast gains a new lifter makes are due to learning to recruit motor units, which is to say training the nervous system. As any long time lifter can tell you, putting on muscle mass naturally takes a long time. The question is does stimulating motor neurons have knock on effects for the rest of the CNS? It's plausible that it does, but with some brief searching I'm not finding any compelling research that it does or doesn't.