IGF1 and Stroke: (3) In addition to the plasticity enhancing trophic factors brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and cytokines (tumor necrosis factor-alpha, interleukin-6) induced in the spinal cord after stroke (69), plasticity at the spinal cord level may be further enhanced through stimulation-induced changes of the micro-environment such as release of signaling molecules, BDNF (70) and/or insulin-like growth father (IGF) in muscle and spinal cord (71).