THE EFFECTS OF SIX WEEKS OF SCIATIC NERVE LIGATION ON DYNACTIN GENE EXPRESSION IN SCIATIC NERVE OF MALE WISTAR RATS

Axonal transport is a vital process in nervous system that protects axons and
nerve terminals through supplying proteins, lipids and mitochondria and clearing folded proteins to
avoid toxicity. Recently it is reported that impairment of motor proteins involved in axonal transportlike
dynactin is a common factor in several neurodegenerative disorders such as Amyotrophic Lateral
Sclerosis (ALS). However, no study was found to investigate the abnormalities in axonal transport due
to decreased physical activity and neuropathic pain.
Materials & Methods: Ten adult male Wistar rats in the weight range of 250±30 gr were randomly
divided into two groups including healthy control (C) (N=5), ligation group (SNL) (N=5). Over the six
weeks, neuropathic pain behavior tests were conducted continually on the groups. In the end of the
sixth weeks, change of dynactin gene expression in sciatic nerve measured with real time technique
and calculated using the 2-ΔΔCT method.
Results: After 6 weeks, neuropathic pain behavior tests showed that pain threshold of thermal
hyperalgesia and mechanical allodynia in the SNL group was significantly lower than the control
group (p= 0.000). In addition, dynactin gene expression in sciatic nerve ligation group compared to
controls decreased significantly (p=0.001).
Conclusion: It seems that neuropathic pain and decreased physical activity is associated with
decreased dynactin gene expression in sciatic nerve fiber. According to the physiologic functions of
dynactin in neurons, this condition may cause functional disorders in the neural and muscular systems