BACKGROUND: Ketamine is a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonists and plays an important role in the treatment of pain.OBJECTIVE: To analyze the preemptive analgesic effects of different doses of ketamine on growth-associated protein-43 (GAP-43) expression in dorsal root ganglion in a rat model of chronic sciatic nerve constricted injury, and to study the differences between high-dose and low-dose ketamineDESIGN: Randomized controlled animal study.SETTING: Medical College of Shantou University. MATERIALS: Thirty-five adult male Sprague Dawley rats were provided by the Experimental Animal Center of Guangzhou University of Traditional Chinese Medicine. Ketamine hydrochloride injection was provided by Hengrui Pharmaceutical Co., Ltd., Jiangsu. METHODS: This study was performed at the Immunological Laboratory, Medical College of Shantou University from September to December 2006. Model of chronic sciatic nerve constricted injury: after anesthesia, the right sciatic nerve was exposed and

来源：中国神经再生研究（英文版） 2008 年 3卷 4期