Macondo crude oil exposure caused specific deformations in the peripheral but not central nervous system. (A-L) 30 hpf control and WAF-treated embryos labeled by immunohistochemistry. (A, B) 3A10 labeled Mauthner neurons in the hindbrain were normal. (C, D) Distribution of Gaba-positive interneurons in the spinal cord were not impacted by WAF treatment (d, DoLa; c, CoSa; v, VeLD; k, KA). (E, F) Anti-Acetylated tubulin (AT) labeling of primary motor axons (arrows) or Rohon Beard sensory neuronal somas (asterisk) were correctly positioned in WAF-treated embryos (lateral view of trunk and spinal cord). (G, H) Qualitatively, Islet1 labeling for primary and secondary motor neurons (lower bracket) and Rohon Beard sensory neurons (upper bracket) were positioned normally. (I, J) The branching pattern of AT-labeled sensory axonal projections along the trunk epidermis was significantly reduced (I', J', magnified views of boxed area in I, J). (K, L) Anti-Gfap labeled radial glia somas in WAF-treated embryo spinal cords (L) were correctly positioned in the ventricular zone (arrowheads) and similar in number to controls (K). (A, B) Dorsal views of the hindbrain. (C-L) Lateral views of the spinal cord (C, D, E, F, G, H, K, L) and trunk (I, J). Scale bars = 50 μm, A-L.