Neural regeneration by stem cells transplantation:Tissue re-generation and homeostasis are principally dependent on tissue stem cells which possess abilities of self-renewal and differen-tiation into multidirectional specialized cell types. In general, stem cells are critical for normal tissue renewal as well as repair after tissue injury. For example, mesenchymal stromal cells and endothelial progenitor cells identified in bone marrow could express several markers of pluripotent stem cells including Nanog and Oct-4. Such cells are also found in peripheral blood as well as in umbilical cord blood which might contribute to neural tissue-repair. Consequently, stems cells could constitute an asset for neural regeneration (Figure 1). Many studies have engaged different techniques for employing the neural stem cells into specific lineages such as neurons and glial cells, which may promote specific functional recovery through neurogen-esis (Nystedt et al., 2006). In addition, preceding studies have revealed the recovery following transplantation of pluripotent stem cells in spinal cord injury models demonstrated the ther-apeutic potential of this approach, meaning that pluripotent stem cell-derived neural stem cells promote the functional recovery of motor neuron following stem cells transplantation into the damaged neural tissues. Amazingly, the motor func-tion in a non-human primate animal model has been restored by transplanting human stem cells (Iwanami et al., 2005). The functional improvement seems to be associated with the grafted neuronal stem cells (Abematsu et al., 2010). Synaptogenesis between graft-derived neurons and host-derived neurons may be possible contributing to the functional recovery. In addition, re-myelination of the de-myelinated axons is a key mechanism in the regeneration of the injured spinal cord neurons (Kawa-bata et al., 2016). So, neural stem cells need to primarily differ-entiate both into neurons and into oligodendrocytes. Axonal growth supported by astrocytes derived from transplanted stem cells may be another foundation for the observed recovery. A previous study had indicated that transplanted stem cells-de-rived astrocytes in an injured spinal cord promote the out-growth of serotonergic axon fibers. Oligodendrocytes derived from transplanted stem cells may also play an essential role in promoting the neural recovery by re-myelination of axons.