Effects of Folic Acid Supplementation on Anxiety- and Depression-like Behaviours, and Locomotion in Captive male African Giant Rats (Cricetomys gambianus, Waterhouse – 1840) Subjected to Chronic Physical Immobilisation

The aim of the study was to evaluate the impact of physical immobilisation and folic acid (FA) supplementation on neurobehaviour in African Giant rats, AGRs (Cricetomys gambianus, Waterhouse-1840). Twenty wild adult male captive AGRs were randomly divided into four groups of five rats each. Group 1 AGRs were neither immobilised nor administered FA. Groups 2 and 3 AGRs were subjected to physical immobilisation, which lasted six hours per day for 21 days. Group 3 AGRs, in addition, received FA-supplemented feed, at the concentration of 3.5 mg/kg feed for 10 consecutive days immediately following the immobilisation protocol. Group 4 AGRs were not immobilised, but received FA-supplemented feed as in group 3 AGRs. All AGRs were evaluated for anxiety- and depression-like behaviours, and locomotor activity using Elevated Plus Maze and Open Field Test, respectively. The results showed that both the percentage open arm entry and number of squares crossed were significantly (P < 0.05) reduced in the immobilised AGRs (groups 2 and 3), but the reduction was less (P < 0.05) in those that received FA post immobilisation (group 3). The percentage open arm exploration was significantly (P < 0.05) lower, while the rearing activity was significantly (P < 0.05) higher in the immobilised AGRs that received no FA supplementation (group 2). In conclusion, the AGRs that were subjected to chronic physical immobilisation displayed anxiety- and depression-like behaviours, and performed poorly in the tasks for locomotor functions. Post-immobilisation FA supplementation ameliorated the effects.