Red circles represent Clarke's column in dorsal spinocerebellar tract neurons (ccDSCT), dorsal horn dorsal spinocerebellar tract neurons (dhDSCT), spinal border neurons (SB) and Ib-ventral spinocerebellar tract neurons (VSCT). Green circles represent excitatory interneurons in reflex pathways to motoneurons (MN) activated by primary afferents and descending systems. Blue lines and diamonds represent neurons that express vesicular glutamate transporter 1 (VGLUT1) in their axon terminals. Green lines and diamonds represent neurons that express vesicular glutamate transporter 2 (VGLUT2) in their axon terminals. CINs, commissural interneurons; INs, interneurons; MNs, motoneurons.