Neurotrophic factors have been demonstrated to rescue damaged axons and thereby promote recovery of function in acute models of spinal cord injury. Here we transplanted fibroblasts genetically modified to express brain-derived neurotrophic factor (BDNF) or neurotrophic factor-3 (NT-3) into a chronic spinal cord injury (see Tobias et al., SFN Abstr 01). Adult rats received a complete C3/C4 hemisection and behavioral recovery was assessed over 5 weeks. The following week they then received control transplants of gel foam or gel foam with unmodified fibroblasts (operated controls), or a combination of fibroblasts modified to secrete either BDNF or NT-3 (experimentals). Behavioral recovery was assessed over the next 10 weeks. Experimental rats showed recovery from heat-induced hyperalgesia and postural adjustment deficits. Similar levels of recovery between groups were observed in the grid test, a sensitive measure of corticospinal function, and the Von Frey test, a measure of mechanical allodynia. In both ope...