Background & Aims

Spinal microgliosis appears to be causally related to pathological pain states which commence after peripheral nerve injuries. However, the roles of distinct classes of primary afferents in the mechanism of this microglial response have not been elucidated.

Methods

In this study, we addressed this issue utilizing quantitative immunohistochemistry and stereological techniques to evaluate spinal microglia densities after selective transection of cutaneous (saphenous) or muscle (tibial branches to the gastrocnemius muscles) nerves in rats.

Results

Quantitative estimation of microglia density revealed a significant, about three-fold increase in Rexed’s laminae I-IV of the spinal dorsal horn ipsilateral to the transection of the saphenous nerve. In contrast, no significant differences in microglia densities were measured in the dorsal horn after transection of branches of the tibial nerve innervating the medial and lateral gastrocnemius muscles. However, intense pericellular microglia reaction was observed around ventral horn motoneurons after transection of muscular but not cutaneous nerves.

Conclusions

The present findings suggest a prominent role for cutaneous but not muscle primary afferents in the initiation and maintenance of peripheral nerve injury-induced spinal microgliosis. The findings may bear of importance for the mechanisms of neuropathic pain brought about by damage to peripheral nerves.

This work was supported by the research grant of the National Research, Develpment and Innovation Office, K-138568

References

Szeredi ID, Jancsó G, Oszlács O, Sántha P., Prior perineural or neonatal treatment with capsaicin does not alter the development of spinal microgliosis induced by peripheral nerve injury. Cell Tissue Res. 2021; 383(2):677-692. doi: 10.1007/s00441-020-03285-8.

Presenting Author

Péter Sántha

Poster Authors

Péter Sántha

PhD

University of Szeged

Lead Author

Gábor Jancsó MD

DSc

Department of Anatomy, Histology and Embryology, University of Szeged, Szeged, Hungary

Lead Author

Ivett Dorina Kozma-Szeredi

MSc

Department of Physiology, University of Szeged and Goodwill Pharma Plc., Szeged, Hungary

Lead Author

Anett Somogyi

Department of Anatomy, Histology and Embryology, University of Szeged, Szeged, Hungary

Lead Author

Topics

  • Mechanisms: Biological-Systems (Physiology/Anatomy)