“…Simple and stereotyped movements, similar to human embryonic SB, have been reported as the first spontaneous motor activity in various animals including birds (Hamburger,1963; Hamburger and Balaban,1963; Oppenheim,1975), fish (Corner,1977; Preyer,1885), amphibians (Preyer,1885; Corner,1977), and mammals such as the mouse (Hanson and Landmesser,2003), rat (O'Donovan et al,1998), sheep (Stockx et al,2007), and guinea pig (Preyer,1885; Kan et al,2009; Sekulić et al,2009). The earliest spontaneous motor activity in the chick and mouse embryos is highly cyclic, spinal in origin, and has an influence on motor axon pathfinding (Provine and Rogers,1977; Hanson et al,2008).…”