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Effect of Treadmill Exercise on Serotonin Immunoreactivity in Medullary Raphe Nuclei and Spinal Cord Following Sciatic Nerve Transection in Rats


The serotoninergic system modulates nociceptive and locomotor spinal cord circuits. Exercise improves motor function and changes dopaminergic, noradrenergic, and serotonergic central systems. However, the direct relationship between serotonin, peripheral nerve lesion and aerobic treadmill exercise has not been studied. Using immunohistochemistry and optic densitometry, this study showed that the sciatic nerve transection increased the serotoninergic immunoreactivity in neuronal cytoplasm of the magnus raphe nuclei of trained and sedentary rats. In the dorsal raphe nucleus the increase only occurred in sedentary-sham-operated rats. In the spinal cord of trained, transected rats, the ventral horn showed significant changes, while the change in dorsal horn was insignificant. Von Frey’s test indicated analgesia in all exercise-trained rats. The sciatic nerve functional index indicated recovery in the trained group. Thus, both the aerobic treadmill exercise training and the nervous lesion appear to contribute to changes in serotonin immunoreactivity.

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This study was supported by grants from Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Coordenação de Aperfeiçoamento de pessoal de nível Superior (CAPES).

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Correspondence to Maria Cristina Faccioni-Heuser.

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Korb, A., Bonetti, L.V., da Silva, S.A. et al. Effect of Treadmill Exercise on Serotonin Immunoreactivity in Medullary Raphe Nuclei and Spinal Cord Following Sciatic Nerve Transection in Rats. Neurochem Res 35, 380–389 (2010).

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  • Peripheral nervous lesion
  • Serotonin
  • Aerobic exercise
  • Pain
  • Analgesia
  • Functional recovery