Gender-related Differences in Rat Sciatic Nerve Regeneration after Autoplasty and Intraoperative Electroneurostimulation

INTRODUCTION. According to the literature, intraoperative electrical neurostimulation (IES) after autoneuroplasty (AN) accelerates the regenerative growth of axons. It is unknown whether sexual dimorphism occurs in peripheral nerve regeneration after AN and with single-dose IES. AIM. To identify possible gender-related differences in the regeneration of the sciatic nerve (SN) after AN resection of the defect of its tibial portion and a single IES in mature rats. MATERIALS AND METHODS. 72 male (n = 39) and female (n = 33) rats underwent resection and AN of the tibial portion of the SN. Series 1 — non-stimulated control, series 2 — IES session 40 minutes. The tibial functional index (TFI) was calculated from the paw prints; Histomorphometric parameters of myelinated nerve fibers (MF) of the tibial nerve (TN) were determined. RESULTS AND DISCUSSION. In series 1, 2 months after surgery, males were found to have higher values of the numerical density of MVs of the WBN and axon diameters (DA) than in females. After 4 months, YES and MV diameters are larger in females. After 6 months, females have greater myelin sheath (MS) thickness. TFI in series 1 decreases towards the end of the experiment, especially in males. In series 2, 2 and 4 months after surgery, in females the DA, MS, and MF diameters were greater than the values in series 1; after 6 months, only MS and MF diameters were greater. In series 2 males, 2 and 4 months after surgery, the MS and MF diameter are greater than in series 1, and after 6 months, all dimensional parameters in series 2 males are higher than in series 1 males. TFI in series 2 is greater than the values in series 1 and increases towards the end of the experiment, especially in males. CONCLUSION. 2 months after AN, the growth and differentiation of nerve fibers in males is faster than in females, then the differences are inverted. Despite the increase in histomorphometric indicators of regeneration, in unstimulated animals, by the end of the experiment, TFI decreases, especially in males. In stimulated rats, compared to unstimulated ones, the morpho-functional indicators of regeneration at all periods of the experiment are better, to a greater extent in males.