Axonal path finding of the accessory nerve

• Applicant: Professor Dr. Ruijin Huang
• Subject Area: Developmental Neurobiology ; Developmental Biology
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 404081011

Axons of the spinal accessory nerve (the eleventh cranial nerve, SAN) extend cranially along the cervical spinal cord across many segments after exiting the neural epithelium through the dorsal root. Only very few studies have investigated this axonal detour unparalleled within the entire peripheral nerve system. Our preliminary data show that the neural crest cells form a boundary cap on the exit point and play an important role during the longitudinal extension of the SAN axons. Our observations suggest that Neuropilin 2 may mediate the guidance function of the boundary cap. Furthermore, we observed that a sensory ganglion promotes the outgrowth of the accessory axons via neurotrophic factors. In this project, we will further investigate how the Semaphorin/Plexin/Neuropilin signal axis controls the longitudinal extension of the SAN axons and whether a sensory ganglion guides the ventral projection through a sensory-motor-axon coupling mechanism. Additionally, we will investigate the function of BMPs from the roof plate and Wnt gradients along the longitudinal axis during the formation of the accessory nerve.

• DFG Programme: Research Grants