Riyi Shi

Title:

Professor

PhD Granting Institution:

M.D. Shanghai Second Medical University, 1984 Ph.D. Purdue University, 1994

Contact:

Email Address: riyi@purdue.edu
Office Phone: 765-496-3018

Primary Training Group:

Integrative Neuroscience

Secondary Training Groups:

Biotechnology

Current Projects:

My laboratory is interested in the cellular and molecular underlying mechanism of nerve damage and recovery. We are particularly interested in the responses of the mammalian spinal cord following mechanical injury. We employ a noval double sucrose-gap chamber developed in this laboratory, for physiological recording and subsequently histological analysis of isolated guinea pig spinal cord. We have made progress in both understanding the nature of the injury as well as producing new potential treatments. For instance, we have been investigating the effect of 4-aminopyridine, a potassium channel blocker, in enhancing action potential conduction in chronic and acutely injured mammalian spinal cord. The search for other drugs with potential therapeutically value is also being conducted. Such studies provide strong support for the effective use of certain drugs (like 4-AP and methylprenisolone) in treating clinical spinal cord injury in man. We are also interested in the effects of physiological variables, such as ionic concentrations, O2 tension, temperature and pH in controlling membrane sealing after axonal damage. Sealing is a critical step in the recovery process following spinal cord injury. More recently, collaborating with Dr. Borgens, a new area of research has been identified. We have successfully reconnected two completely severed guinea pig spinal cord segments using a molecular surfactant (polyethylene glycol, or PEG). We have also shown that PEG can enhance the recovery of spinal cord following compression injury, a more clinically relevant type of injury. Currently, in vivo as well as in vitro investigations are underway to explore the clinical usage of PEG.