Medical Student Research Fellowship for Summer 2005

Two Projects

Mentor: Keith Tansey, MD, PhD
Department: Neurology
Room number: CS5.532, L1.232
Mail Code: 8897
Phone number: 88747, 80487
E-mail: keith.tansey@utsouthwestern.edu
Project title: Cell Biology of Motoneuron Sprouting

Human subjects IRB approved project number (where applicable):

Animal subjects IRB approved project number (where applicable):
0971-04-01-1

Project Type (patient-based research, animal-based research, or basic research; this characterization is only to permit a general classification for grouping similar types of projects) animal-based

Brief Description of Project:
Neuronal sprouting is probably a major mechanism by which the central nervous system attempts to repair itself. The only CNS neurons that we can reliably make sprout by injuring their neighbors are motoneurons in the ventral horn of the spinal cord. This project involves generating a unilateral partial peripheral nerve injury in rodents to stimulate motoneuron sprouting. One week before sacrifice, animals undergo injection of retrograde tracer into a specific muscle on both sides of the body to label sprouting motoneurons on one side of the cord and their normal counterparts on the contra-lateral side of the cord. Immunohistochemistry will be used to characterize changes in cell soma biology such as alterations in cell size, growth factor receptors, cytoskeletal elements, cell metabolism or other features in sprouting motoneurons over time. We hope to characterize a cellular profile of sprouting CNS neurons that could be used to identify sprouting spinal neurons after injury

Project title: Activity Dependent Plasticity in Spinal Circuits after Injury

Human subjects IRB approved project number (where applicable):

Animal subjects IRB approved project number (where applicable):
0971-04-07-1, 0971-04-03-1, and 0971-04-04-1

Project Type (patient-based research, animal-based research, or basic research; this characterization is only to permit a general classification for grouping similar types of projects) animal-based

Brief Description of Project:
After spinal cord injury, spinal neural circuits undergo plasticity and partial recovery occurs. Treatment with locomotor training, however, improves functional recovery of gait and perhaps other functions. We are interested in learning how different spinal circuits are affected by spinal cord injuries of varying severity and time of recovery and how those circuits are changed by locomotor training. Using electrophysiological and histological techniques, we are studying an intersegmental spinal reflex (a pain reflex) and the ability to activate spinal neural circuits for stepping (central pattern generator) from supraspinal locomotor centers after spinal cord injury. Animals undergo surgery and spinal cord contusion, post-operative care, repeat surgery for electrophysiology and then perfusion with fixatives for spinal cord harvest and histological processing. Animals undergoing locomotor training are trained on a computer controlled robotic device which can impose stepping movements on paralyzed animals but can also measure the recovery of stepping kinematics as stepping recovers.

Previous Research Activities or Publications with Medical Students:
Tansey, K., Smith, C., Gerety, P., and Botterman, B., Recovery in an intersegmental spinal reflex after contusion injury in the rat, American Spinal Injury Assoc. Abstr., 2005 (Award Platform Session presentation) - Pat Gerety, MS1, 2004

Adipose Derived Neural Progenitor (ADNP) Cells: A Novel Source for Cell Replacement Therapy in Spinal Cord Injury, M.A. Warren, M.K. McCoy, T.N. Martinez, C.G. Smith, B.R. Botterman, M.G. Tansey, and K.E. Tansey (2005 Medical Student Research Forum winner) - Mary Warren, MS1, 2004

Pawprint Analysis in Recovery from Peripheral Nerve and Spinal Cord Injury - George Zinkhan, MS1, 2004

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