An isolated muscle progenitor cell being MyoD positive, CD34 negative and CD45 negative is disclosed. The muscle progenitor cell is genetically modified to express at least one neurotrophic factor. In addition, cell populations are disclosed, comprising at least four subpopulations of muscle cells each being genetically modified to express a different neurotrophic factor, wherein said neurotrophic factor is selected from the group consisting of glial derived neurotrophic factor (GDNF), insulin growth factor (IGF-1), vascular endothelial growth factor (VEGF) and brain-derived neurotrophic factor (BDNF). Uses of the cell populations are also disclosed.