INDELOXAZINE HYDROCHLORIDE IMPROVES IMPAIRMENT OF PASSIVE-AVOIDANCE PERFORMANCE AFTER FLUID PERCUSSION BRAIN INJURY IN RATS

We studied behavioral and histological changes after fluid percussion brain injury and the effects of indeloxazine hydrochloride, a cerebral activator, on these post-traumatic changes in rats. An acquisition tr ial in passive avoidance task was conducted on the 3rd day after injur y. The latency of step-through in injured rats was significantly (p<0. 05) shorter than that in sham-operated rats on the 4th, 10th and 14th days after the operation. There were injury-induced neurological defic its on days 1-4 post-injury. Histological changes were observed in the peripheral area of the cortical lesion at the impact site and in the thalamus but not in the hippocampus on the 14th day. Indeloxazine (10 and 20 mg/kg, p.o.) administered once a day from the 3rd (30 min prior to the acquisition trial) to the 9th day after injury significantly ( p < 0.05) improved the impairment of the passive avoidance performance without affecting locomotor activity. Indeloxazine showed no signific ant effects on either neurological deficits or the cortical lesion are a. These results suggest that impairment of passive avoidance performa nce occurs without apparent histological damage in the hippocampus aft er fluid percussion brain injury and is attenuated by post-traumatic t reatment with indeloxazine. Copyright (C) 1996 Elsevier Science Ltd.