Development of putative GABA-ergic synaptic contact between HSSC and the host neurons. A: Confocal analysis of hSYN/GFP/NeuN-stained sections shows numerous hSYN punctata associated with GFP+ processes derived from grafted cells. Some of the hSYN/GFP+ terminals were found to be in the vicinity of the host interneurons or α-motoneurons (A; inserts; white arrows). B: Triple staining with GAD65/67/GFP/NeuN antibody showed numerous double-stained GAD65/67/GFP+ terminals residing on or in the close vicinity of lumbar α-motoneurons (white arrows). (Scale Bars: A: 150 μm (inserts: 30 μm); B: 20 μm). HSSC, human fetal spinal cord-derived neural stem cells.