Table 1.
Recommended sample sizes to detect a therapeutic benefit for different behavioral tests in three HD mouse models
| Mouse model | N171-82Q | zQ175 | BACHD | |||||||
| Disease stage | Early | Mid | Late | Late | Early | Mid | Late | Early | Mid | Late |
| Age (Unit) | 6 | 10 | 14 | 18 | 6 | 8.5 | 18 | 2 | 6 | 12 |
| Weeks | Months | Months | ||||||||
| Weight | ||||||||||
| 25% | ND | ND | 21 / grp | 35 / grp | ND | ND | ND | ND | ND | ND |
| 50% | <6 / grp | 9 / grp | ND | ND | 16 / grp | 42 / grp | 20 / grp | 58 /grp | ||
| 75% | <6 / grp | <6 / grp | 62 / grp | 46 / grp | 8 / grp | 19 / grp | 9 / grp | 26 /grp | ||
| Other | 100% : 35 / grp | 100% : 26 / grp | 85% : 15 / grp | 100% : 15 / grp | ||||||
| Rotarod Performance | ||||||||||
| 25% | ND | ND | ND | <6 / grp | ND | ND | ND | ND | 54 / grp | ND |
| 50% | ND | ND | ND | <6 / grp | ND | ND | 27 / grp | 15 /grp | ND | |
| 75% | ND | 49 / grp | 20 / grp | <6 / grp | 44 / grp | ND | 12 / grp | 7 /grp | 53 /grp | |
| Other | 100% : 50 / grp | 100% : 28 / grp | 100% : 12 / grp | 100% : 25 / grp | 100% : 47 / grp | 100% : 30 / grp | ||||
| FGS | ||||||||||
| 25% | ND | ND | ND | 10 / grp | ND | NA | NA | 56 / grp* | 40 / grp* | ND |
| 50% | 54 / grp | 21 / grp | 31 / grp | <6 / grp | 48 / grp | 15 / grp* | 10 / grp* | 43 / grp* | ||
| 75% | 24 / grp | 10 / grp | 14 / grp | <6 / grp | 22 / grp | 7 / grp* | 5 / grp* | 19 / grp* | ||
| Other | 95% : 15 / grp | 90% : 15 / grp | 100% : 11 / grp* | |||||||
| DR – T-turn | ||||||||||
| 25% | ND | ND | ND | ND | ND | NA | NA | 58 / grp | ND | 23 / grp |
| 50% | ND | 15 / grp | 6 / grp | |||||||
| 75% | 43 / grp | 7 / grp | <6 / grp | |||||||
| Other | 100% : 24 / grp | |||||||||
| DR – T-total | ||||||||||
| 25% | ND | ND | ND | ND | ND | NA | NA | ND | ND | 18 / grp |
| 50% | ND | 45 / grp | ND | <6 / grp | 27 / grp | <6 /grp | ||||
| 75% | 31 / grp | 20 / grp | 32 /grp | <6 / grp | 12 /grp | <6 /grp | ||||
| Other | 100% : 18 /grp | 90% : 14 / grp | 100% : 18 /grp | |||||||
| DR – Latency | ||||||||||
| 25% | <6 / grp | ND | ND | ND | ND | NA | NA | <6 / grp | ND | ND |
| 50% | <6 / grp | 48 / grp | ND | <6 / grp | ||||||
| 75% | <6 / grp | 22 / grp | ND | <6 / grp | ||||||
| Other | 90% : 15 /grp | 100% : 43 /grp | ||||||||
| NB – Cross time | ||||||||||
| 25% | 52 / grp | NA | NA | NA | NA | NA | NA | 12 / grp | 54 / grp | ND |
| 50% | 23 / grp | <6 / grp | 14 / grp | 20 / grp | ||||||
| 75% | 15 / grp | <6 / grp | 6 / grp | 9 / grp | ||||||
| Other | ||||||||||
| NB – Slips | ||||||||||
| 25% | ND | NA | NA | NA | NA | NA | NA | ND | ND | ND |
| 50% | ND | ND | ND | |||||||
| 75% | 35 / grp | ND | 42 / grp | |||||||
| Other | 100% : 20 / grp | 100% : 36 / grp | 100% : 24 / grp | |||||||
| NB – Latency | ||||||||||
| 25% | ND | NA | NA | NA | NA | NA | NA | ND | ND | ND |
| 50% | 62 / grp | ND | ||||||||
| 75% | 28 / grp | 57 / grp | ||||||||
| Other | 100% : 16 /grp | 100% : 37 / grp | ||||||||
| CT – Frequency | ||||||||||
| 25% | NA | NA | NA | NA | NA | NA | NA | ND | 4 months old | ND |
| 50% | 41 / grp* | ND | 19 / grp* | |||||||
| 75% | 19 / grp* | 42 / grp* | 9 / grp* | |||||||
| Other | 100% : 11 / grp* | 100% : 24 / grp* | ||||||||
| AC – Distance | ||||||||||
| 25% | ND | ND | ND | ND | ND | ND | ND | ND | ND | 33 / grp |
| 50% | 22 / grp | 35 / grp | 9 / grp | |||||||
| 75% | 10 / grp | 16 / grp | <6 / grp | |||||||
| Other | 80% : 14 / grp | |||||||||
| AC – Jump | ||||||||||
| 25% | ND | ND | ND | ND | ND | ND | ND | ND | 29 / grp | 16 / grp |
| 50% | 42 / grp | ND | 8 / grp* | <6 / grp | ||||||
| 75% | 19 / grp | 6 / grp* | <6 / grp* | <6 / grp | ||||||
| Other | 85% : 15 / grp | 100% :<6 / grp* | ||||||||
| AC – Rearing | ||||||||||
| 25% | ND | ND | ND | ND | ND | ND | ND | ND | ND | ND |
| 50% | ND | ND | ND | 22 / grp | ||||||
| 75% | 55 / grp | 37 / grp | 42 / grp | 10 / grp | ||||||
| Other | 100% : 45 /grp | 100% : 21 / grp | 100% : 24 / grp | |||||||
HD mice recommended sample sizes to detect a normalization of the behavior by 25, 50, 75% or more. Sample sizes in bold are practical. AC, Activity chamber; CT, Climbing test; DR, Descending rod; FGS, Forelimb grip strength; NA, Not available; NB, Narrow beam; ND, Not determined; T-time, Time to descend the descending rod; T-turn, Time to turn downward on the descending rod; *Weight-corrected data.