Effects of fluoxetine on the 5-HT1A receptor and recovery of cognitive function after traumatic brain injury in rats.

Objective: This study examined the effects of chronic administration of fluoxetine, a selective serotonin reuptake inhibitor, on cognitive performance and 5-HT1A receptor immunoreactivity following traumatic brain injury. Design: Rats received a moderate severity of lateral fluid percussive injury or sham injury 24 hr after surgical preparation. Fluoxetine or vehicle was administered chronically on postinjury days 1-15. Motor performance and Morris water maze performance were assessed on postinjury days 1-5 and 11-15, respectively. Results: Results indicated that chronic fluoxetine treatment did not affect motor or maze performance. Injured groups showed significantly higher 5-HT1A receptor immunoreactivity on postinjury day 15 than sham-injured rats, and fluoxetine treatment did not alter 5-HT1A receptor immunoreactivity. Conclusions: These results indicate that chronic postinjury fluoxetine administration did not influence the recovery of motor or Morris water maze performance following lateral fluid percussive injury. They also indicate that injury-induced changes in the 5-HT1A receptor may contribute to traumatic brain injury-induced cognitive deficits.