Effect of acetylcholine in rat brain in promoting early recovery of spinal cord injury by inhibiting monoamine oxidase enzyme: Preclinical evidence

Abstract

Spinal cord injury (SCI) is one of the most common causes of severe incapacity and has been associated with high health care expenditures. The present study designed to assess the effect of acetylcholine in rat brain (cortex) promotes early recovery of SCI by inhibiting monoamine oxidase enzyme. Male adult wistar rats (200–250 gram in body weight) were kept in isolated cages with 12-day and dark cycle, and were offered regular food and water (as and when required) during the day. Protocol was approved by ethics committees of Soochow University. Rats were distributed into two groups: 1) Test group: SCI group, treated with acetylcholine; 2) Control group (SCI group, not treated with acetylcholine). SCI was induced by clipping between T12 and T13 vertebra. Rats were surrendered by decapitation, and the cortex was removed and was stored at −80°C for investigation. Acetylcholine inhibited acetylcholinesterase enzyme and MAO isoform (MAO-A or -B) in the cerebral cortex. Motor function of rats after inducing SCI was tested using rotarod test, and retention time was measured at different RPM speed (low [10rpm], medium [15] and high/fast [25]) in both the groups. In the rotarod test, the rats with treated with acetylcholine had significantly more retention time as compared to control rats SCI at all rotations (10, 15 and 25 rpm). Whereas, the rats of the control group had significantly lesser retention time as compared to rats with treated with acetylcholine at all rotations (10, 15 and 25 rpm) [p=0.003]. Our study results showed significant improvement in activity of cholinergic and monoaminergic transmission, which thereby improve motor function in rats with SCI after treatment with acetylcholine. This study results suggested, that there is need to target MAO enzyme in brain for developing effective treatment for SCI. The finding of this study gives the new idea to researchers to develop therapy for treatment of SCI based on MAO enzyme target.