Research fellows in the Peripheral Nerve Research Lab work under Susan Mackinnon, MD, chief of the Division of
Plastic and Reconstructive Surgery, other faculty members in the division and faculty from other departments
such as Neurosurgery and Biomedical Engineering.
Some current research projects are:
T cells and their role in immune rejection of nerve allografts. Susan Mackinnon, MD, and Thomas Tung, MD, PIs.
The T helper cell is differentiated into two types: the TH1 and TH2 phenotypes. The goal of the research is to
determine which phenotype plays the predominant role in nerve allograft rejection.
Another project examines how Major Histocompatibility Complex (MHC) Class II molecules participate
in nerve allograft rejection.
Because devastating nerve injuries usually require an allograft or cadaveric graft, patients must undergo
systemic immunosuppression and, thus, are vulnerable to risky side effects. The goal of these research projects
is to find ways to offer alternatives to systemic immunosuppression to allow patients to accept the nerve graft.
The controlled delivery of glial cell line-derived neurotrophic factor (GDNF) for enhancement of peripheral
nerve regeneration. Shelly E. Sakiyama, PhD, PI. With peripheral nerve injuries,
surgeons have been more successful in effecting sensory recovery than motor function. GDNF is known to be a motor-specific
neurotrophic factor. This study investigates the delivery of GDNF to a motor nerve (femoral motor nerve model) to
enhance muscle reinnervation and function. Delivery of the GDNF is achieved through a fibrin-based delivery system
incorporated into a conduit or decellularized allograft. The delivery system was developed by Sakiyama-Elbert.
The research lab has finished work on the delivery of GDNF in a sciatic nerve model and submitted a paper.
Pilot studies have been completed on a femoral nerve model.
Green fluorescent protein (GFP) transgenic rat model. In collaboration with
genOway (Lyon, France), the lab has developed a transgenic Sprague Dawley rat line that constituitively
expresses GFP in neurons. This model enables researchers to study peripheral nerve regeneration in vivo directly
under fluorescent and confocal microscopy. Characterization of this rat model is currently under way.
Preferential motor reinnervation. Terence Myckatyn, MD, PI. Using mice with neurons that fluoresce under a
microscope, the lab is studying whether motor or sensory grafts are better to repair modality-specific injuries.
Mouse femoral nerves are crushed and researchers observe whether the axons go down a motor pathway or sensory pathway.
The project also looks at whether motor nerve regeneration is better in mice that overexpress in GDNF.
Use of neurturin in treatment of botulinum toxin poisinoning. Terence Myckatyn, MD, PI. Botulinum toxin is used
in the treatment of neurologic disorders, gastric disorders and wrinkles and for other aesthetic reasons. The spread
of botulinum toxin can have unintended side effects. This study is investigating whether neurturin, which is closely
related to GDNF, could act as an possible antidote to botulinum toxin.