Estimated number of boutons of the contralateral (A) and ipsilateral (B) corticospinal projection from injection site SDM77-BDA (M1/LPMCd transition area) and case SDM72-FD (LPMCv post-arcuate area) within the anatomical subsectors of lamina VII of spinal segments C5-T1. Each Bar is the estimated number of boutons in each specified lamina VII subsector for an individual case as indicated on the abscissa. Subsector abbreviations: DM, dorsomedial; DL, dorsolateral; VM, ventromedial; VL, ventrolateral; V, ventral