Chronic folic acid administration confers no treatment effects in either a high or low dose following unilateral controlled cortical impact injury in the rat

Purpose: Traumatic brain injury (TBI) is a major health concern today and effective treatments must be developed in order to combat the numerous TBIs that occur each year. Multiple b-vitamins have been shown to have neuroprotective effects, however, folic acid (B₉) has not been widely studied. The current study examined two different doses in a rodent model of controlled cortical impact (CCI) TBI. Methods: Sham procedures or a unilateral parietal controlled cortical impact injury was induced. Rats were administered either vehicle or folic acid in an 80 μg/kg or 800 μg/kg dose. Rats were tested on the bilateral tactile adhesive removal task, rotarod task and the Morris water maze. Brains were examined to determine lesion size and neuronal loss. Results: Neither of the folic acid-treated groups showed improvement on any behavioral task or anatomical measure post-CCI and the high dose group had increased neuronal loss compared to the vehicle. Administration of the high dose in sham animals resulted in some behavioral dysfunction and significant neuronal loss. Conclusions: The results from this study suggest that folic acid may not represent an effective avenue for treatment and that higher doses may actually be detrimental following TBI.