Persistence of high levels of NF-180 protein in giant reticulospinal neurons after axotomy. Paraffin sections were immunostained for total NF-180 with LCM3. A, Section through the middle rhombencephalon, showing several giant bulbar reticulospinal neurons in a control lamprey. B, A similar section in the anterior rhombencephalon 4 weeks after a complete spinal cord transection. C, Section through bulbar reticulospinal neurons at 7 weeks after transection. Note that there is no loss in the intensity of immunostaining, despite the clear reduction in giant reticulospinal neuron NF-180 mRNA illustrated in Figures 4, 6, and 7. Scale bar, 60 μm.