A—D, Immunoperoxidase labeling for PDGF αR in the dorsal column (wm; A, B) and dorsal horn (gm; C, D) ofwt (A, C) and jp(B, D) cervical spinal cord at P18. There is an increased number of PDGF αR+ cells in jp dorsal column but not dorsal horn. Scale bar, 50 μm. E, Number of PDGF αR-immunoreactive cells per unit area in the cervical dorsal column (white matter) and dorsal horn (gray matter) ofwt and jp spinal cord at P18. Error bars represent SD (n = 3). gm, Gray matter; wm, white matter.