| Clue | Source | Date |
|---|---|---|
| Muscle-controlling nerve cell | USA Today | 30 Jul 2018 |
| Muscle-controlling nerve cell | ||
| Spinal cord cell needed for muscle contraction | New York Times | 13 Jun 2016 |
| Spinal cord cell needed for muscle contraction | ||
| Need to twitch | Newsday | 08 Aug 2015 |
| Need to twitch | ||
| Muscle-controlling cell |