Investigation of the effect of irisin hormone on electrophysiological changes in experimental spinal cord injury model

Spinal cord injury (SCI) is a significant health problem affecting millions of people worldwide, significantly reducing their quality of life. The pathophysiology of SCI includes both the primary injury resulting from trauma and secondary injury processes that develop over time. Due to the limited regenerative capacity of nerve tissue, reversing functional losses resulting from the secondary injury process is extremely difficult. Therefore, developing new treatment approaches is of paramount importance. In recent years, exercise has been shown to support neural functions by having positive effects on both the central nervous system and skeletal muscles. It is thought that the myokine irisin, released during exercise, may regulate energy metabolism and also exert neuroprotective effects on the nervous system. This study investigated the effects of irisin on motor function and nerve conduction after spinal cord injury. In the study, male Sprague Dawley rats were divided into four groups: control, sham, SCI + deionized water, and SCI + irisin. The SCI model was induced with clip compression at the T9-T10 level, and the effects of irisin were investigated with intraperitoneal injections over six weeks. At the end of the experiment, basic electrophysiological measurements were made, including the Hoffmann reflex (H-reflex), motor evoked potentials (MEP), and somatosensory evoked potentials (SEP). In intergroup comparisons, the data were assessed for normal distribution. Statistical significance was set at p<0.05. The findings revealed a significant decrease in motor and sensory potentials after SCI, but irisin administration partially compensated for these losses. In particular, a significant decrease in motor and sensory amplitudes and a significant prolongation of latencies were observed (p<0.05), while no significant difference was found between the groups in terms of the H-reflex (p>0.05). These results suggest that irisin hormone has neurotransmitter-supporting effects and may contribute to treatment. In conclusion, it can be said that irisin hormone has a promising potential as a complementary biological agent in the treatment of spinal cord injuries. Keywords: Spinal cord injury, irisin, Motor Evoked Potentials, Sensory Evoked Potentials, H-Reflex.