FIG. 1.

Post-injury carnosic acid (CA) treatment improves motor and cognitive performance after repeat mild traumatic brain injury (mTBI). (A) Timeline for injury, CA administration, motor and cognitive assessments. (B) Length of apnea, (C) period of suppression of pain reflex, and D) the duration of suppression of righting reflex are increased after repetitive mTBI (rmTBI) rmTBI (n = 10 sham, n = 16 rmTBI) *significant difference compared with sham. Mice sustaining rmTBI made significantly more (E) left and (F) right foot fault errors (assessed using a 2 cm × 2 cm wire grid) that were reduced by CA treatment. *significant difference between vehicle and CA treated animals. The rmTBI acutely increased adenosine triphosphate (ATP)-linked oxygen consumption rate (OCR) and proton leak in the (G) hippocampus, but not the (H) cortex. These changes were unaffected by CA treatment. *significant differences compared with sham. (I) The rmTBI mice treated with CA had improved learning in the Barnes maze tested 15 days after the last injury and CA treatment as indicated by significantly reduced latencies to enter the escape hole during training. *significant difference between vehicle and CA treated mice. The rmTBI mice treated with CA had improved (J) short-term and (K) long-term memory as indicated by reduced latency to find the target hole and fewer errors when tested 30 min and 24 h after training. *significant difference between vehicle and CA treated mice. Data are presented as mean ± standard error of the mean. *p < 0.05.