EFFECTS OF DORSAL ROOT AVULSION INJURY ON THE SPINAL GANGLIA AND SPINAL CORD

01/29/2020

Máté Vass¹, Dénes Török¹, Máté Vass¹, Krisztián Pajer¹, Antal Nógrádi¹

¹ Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Szeged, Szeged

High impact vechicle accidents and sport injures often result in avulsion injuries when the dorsal and ventral roots of the spinal cord are torn out. The changes in the ventral horn after ventral root injury are well-known, however, there are only a few studies investigating the effects of the avulsed dorsal root. In this study, our goal was to examine the avulsion-induced changes in the cell population of the affected dorsal root ganglia and the spinal cord. Lumbar 4 and 5 (L4-5) dorsal roots were avulsed. The animals were perfused 3 or 21 days after the surgery. The injured and contralateral dorsal root ganglia along with the L4-5 spinal segments were removed. Immunohistochemical analysis carried out on cryostat sections included neurofilament 200 kDa protein, Transient Receptor Potential cation channel subfamily V member 1 (TrpV1) receptor, Calcitonin gene-related peptide (CGRP) immunostainings and Griffonia Simplicifonia Isolectin-B4 (GSAB4) histochemistry. These aimed at the changes both in the ganglia and the spinal cords following the injurys.Our preliminary data suggest that there are no significant topological or morphometric changes in the TRPV-1 and CGRP expression levels even 21 days after the injury in the L4-5 ganglia. However, dorsal root avulsion injury severely affected the ipsilateral gracile tract of the spinal cord. Moreover, we could detect an impact of the injury on the contralateral side of the cord, too.It can be concluded that this avulsion injury model represents well the subsequent changes in the spinal cord, while the ganglion cells remain preserved.