Figure 1. aPKC and Ryk are expressed in ChAT⁺ motor neurons and CC1⁺ oligodendrocytes in the adult ventral spinal cord.

Immunostaining of coronal sections of lumbar spinal cords of 60 day-old mice for aPKC (A–C) or Ryk (E–G), Neurofilament 200 (NF-200) marker or astrocyte marker GFAP or postmitotic oligodendrocyte CC1 marker and motor neuron marker ChAT. aPKC and Ryk are not expressed in GFAP⁺ cells (B,F). Arrows in A–C and E–G indicate neurons double labeled for aPKC or Ryk and ChAT. Arrowheads in A indicate aPKC⁺ NF-200⁺ ChAT⁻ neurons. Arrowheads in C indicate aPKC⁺ CC1⁺ cells. Arrowheads in E indicate colocalization of Ryk with ChAT immunostaining in motor axons in the ventral white matter. Arrowheads in G indicate Ryk⁺ CC1⁺ cells. D and H are higher magnifications showing the intracellular localization of aPKC and Ryk immunoreactivity. aPKC immunoreactivity is localized in both cytoplasm and nucleus (arrowheads in D). Ryk immunoreactivity is mainly localized in the cytoplasm of motor neuron cell bodies (arrows in H) and in fibers (arrowheads in H). Scale bars: 100 µm (A–C, E–G), 50 µm (D,H).