Olfactory Nerve Transection Transiently Activates Olfactory Ensheathing Cells in Xenopus laevis Larvae.

Olfactory ensheathing cells (OECs) play a crucial role in supporting the continuous turnover of olfactory receptor neurons by promoting axon growth and targeting. While OECs have been extensively studied in mammals for their potential in treating nerve injuries, little is known about these cells in non-mammalian vertebrates. We identified and characterized the morphology of OECs, fibroblasts, and macrophages in the olfactory system of Xenopus laevis larvae. Additionally, we used antibodies against phosphorylated ribosomal protein S6 (p-rpS6) to visualize the activation of non-neuronal cells in the olfactory nerve (ON) after transection. Various non-neuronal cells in the ON, including OECs, fibroblasts, and macrophages, showed a transient increase in the p-rpS6 signal following transection. Our study provides the first description of non-neuronal cells populating the ON of larval X. laevis, and it suggests that rpS6 phosphorylation in these cells may be essential after injury and potentially supports regeneration of the ON. These findings contribute to a broader understanding of OECs and their role in nerve regeneration across species.