NGF stimulates extensive neurite outgrowth from implanted dorsal root ganglion neurons following transplantation into the adult rat inner ear.
Neuronal tissue transplantation is a potential way to replace degenerated spiral ganglion neurons (SGNs) since these cells cannot regenerate in adult mammals. To investigate whether nerve growth factor (NGF) can stimulate neurite outgrowth from implanted neurons, mouse embryonic dorsal root ganglion (DRG) cells expressing enhanced green fluorescent protein (EGFP) were transplanted into the scala tympani of adult rats with a supplement of NGF or artificial perilymph. DRG neurons were observed in the cochlea for up to 6 weeks postoperatively. A significant difference was identified in the number of DRG neurons between the NGF and non-NGF groups. In the NGF group, extensive neurite projections from DRGs were found penetrating the osseous modiolus towards the spiral ganglion. These results suggest the possibility that embryonic neuronal implants may become integrated within the adult auditory nervous system. In combination with a cochlear prosthesis, a neuronal implantation strategy may provide a possibility for further treatment of profoundly deaf patients.
Hu
Zhengqing
Z
Center for Hearing and Communication Research, Karolinska Institute, SE-171 76 Stockholm, Sweden. Zhengqing.hu@cfh.ki.se
Ulfendahl
Mats
M
Olivius
N Petri
NP
D000818:Animals; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D007758:Ear, Inner / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology / Q000637:transplantation*; D006085:Graft Survival / Q000187:drug effects / Q000502:physiology; D049452:Green Fluorescent Proteins; D020439:Growth Cones / Q000187:drug effects / Q000648:ultrastructure; D006319:Hearing Loss, Sensorineural / Q000473:pathology / Q000628:therapy*; D008297:Male; D020932:Nerve Growth Factor / Q000494:pharmacology*; D009416:Nerve Regeneration / Q000187:drug effects / Q000502:physiology; D016501:Neurites / Q000187:drug effects* / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000637:transplantation; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012533:Scala Tympani / Q000473:pathology / Q000601:surgery; D013136:Spiral Ganglion / Q000473:pathology / Q000601:surgery
D049452:Green Fluorescent Proteins; D020932:Nerve Growth Factor