However, MNs are not homogeneous throughout the CNS because they exhibit distinct morphologies and patterns of connectivity, which underlie their different physiological functions. Hence, within a single region, MNs that perform closely related functions can be further subdivided, both anatomically and physiologically. The identities of specific MN subtypes and their target projections are controlled by selective cell-type expression of transcription factors, notably members of the Hox, LIM, Nkx6, and ETS families (Stifani, 2014). This provides the fundamental mechanism for spinal MN diversification and connectivity to specific peripheral muscle targets. Thus, to generate movement, MNs integrate information from sensory structures and transform it into precise temporal and magnitudal activation of muscles.