To answer your question on taper, Coach Kredich suggested to me that they did not stop hard training 6 weeks out, they just stopped that hard of a set. He would prescribe lots of 25s practicing each portion of the race, for example, just not the whole race, a few times through, all at once.
Do you have any suggested resources to study more on nervous system training? Kredich suggested Tudor Bompa's book on periodization. It has some interesting ideas. I still haven't found comfortable answers to a few questions such as:
1. Why does it take the nervous system so long to recover?
2. What exactly is nervous system fatigue? Using up neurotransmitters? Messing with Na/K levels? Messing with Ca levels?
3. Could part of the aerobic base concept be training the nervous system to recover faster?
4. How can you recognize nervous system fatigue from muscle fatigue? (my guess is that nervous system fatigue would prevent you from ever reaching max speed where muscle fatigue would prevent you from maintaining it. But I have not found any reading that supports that idea.)
5. What is different about cats and dogs that makes them different?
The only readings I have found on nervous system training discuss coordination, weight training with multijoint movements, etc. Not recovery.