Fig. 7

Columnar organization of motor neuron pools and the topography of nerves innervating limb muscles in tetrapods. Motoneuron columnar organization is based on the study using the chicken [259]. Topography of nerves and skeletal elements of Tarentola (Ascalabotes) fascicularis (gecko) illustrated in Sewertzoff [114] is shown as a representative. Skeletal elements of the metapterygial axis are colored in blue, and the other (preaxial) skeletal elements in gray. Nerves for the scapulohumeralis (green) and flexor carpi ulnaris (orange) muscles are shown as examples of correspondences between motoneuron pools and their respective target muscles. cor, coracoid; fcu, nerve for the flexor carpi ulnaris muscle; fcun, motoneuron for the flexor carpi ulnalis muscle; hum, humerus; scap, scapula; I–V, digits I–V; LMC, lateral motor column; sch, nerve for the scapulohumeralis muscle; schn, motoneuron for the scapulohumeralis muscle; pl.br, plexus brachialis; rad, radius; ul, ulna