Table 1.
Summary of Behavioral Responses following Repeated CHIMERA
| Response dimension | Injury effects | Main effect of Sex or Injury × Sex Effect |
|---|---|---|
| Righting reflex (Fig. 1B) | Significant effect of Injury (Injury > Sham) on all injury days | No effect |
| OF total distance traveled (Fig. 5A) | Injury × Day interaction. Hypoactivity in injured mice neared significance (adjusted p = 0.0525) on post-injury Day 1. | Main effect of sex (Female > Male) |
| OF speed while mobile (not shown) | No main effect | Injury × Sex interaction. Female Sham speed > Male Sham speed |
| OF time immobile (Fig. 5B) | Effect of injury in females only. | Injury × Day interaction in females; on Day 1, injured females were more immobile than sham-treated females |
| Rotarod (Fig. 6) | Injury × Day interaction. Injured mice were impaired on Days 1, 7, and 14, but not on Day 21 following injuries. | No effect |
| Y-maze spontaneous alternation (not shown) | No effect | No effect |
| MWM latency—standard training (Fig. 7A) | Significant Injury × Day interaction. Injured mice had significantly longer latencies to find the platform on Days 2, 3, and 4 of training. | No effect |
| MWM distance—standard training (Fig. 7B) | Significant Injury × Day interaction. Injured mice had significantly longer distances to find the platform on Day 3 of training. | No effect |
| MWM latency—reversal training (Fig. 7A) | Effect of injury in males only. | Injury × Day effect in males only; injured male mice had significantly longer latencies to find the platform than sham male mice on Days 2, 3, and 4 of reversal training |
| MWM distance—reversal training (Fig. 7B) | No effect | No effect |
| MWM swim speed (Fig. 8C) | Main effect of Injury (Sham > CHIMERA) | No effect |
| MWM probe trial—standard (Fig. 8A and 8B) | Main effect of Injury on time spent in correct (NW) quadrant and number of annulus crossings (Sham > CHIMERA) | No effect |
| MWM probe trial—reversal (Fig. 8C and 8D) | Effect of Injury in males only | Time in correct (SE) quadrant; Male Sham > Male CHIMERA. Number of annulus crossings; Male Sham > Male CHIMERA. There was also a significant difference between sham-treated mice of the opposite sex, with male sham mice crossing the annulus a greater number of times than female sham mice. |
| MWM visible platform trials (Fig. 7A and 7B) | Main effect of injury on latency and distance to platform; CHIMERA > Sham | No effect |
| TFC—training baseline (Fig. 9A) | No effect | No effect |
| TFC—cue test baseline (Fig. 9B) | No effect | Injured female > Injured male |
| TFC—cue test, total freezing during cues (Fig. 9C) | Main effect of injury, CHIMERA < Sham | Main effect of sex, Male < Female |
| TFC—cue test, total freezing during trace periods (Fig. 9D) | Main effect of injury, CHIMERA < Sham | Main effect of sex, Male < Female |
| TFC—context test (Fig. 9E) | Effect of Injury in males only | Male CHIMERA < Male Sham |
CHIMERA, Closed-Head Impact Model of Engineered Rotational Acceleration; OF, open field; MWM, Morris water maze; TFC, trace fear conditioning.