Fig. 2. TAP-tagged NaV1.7 is down-regulated in the spinal cord after dorsal rhizotomy.
Four weeks after dorsal rhizotomy on the right L5, the spinal cords of TAP-tagged NaV1.7 mice were extracted, and immuno-EM was performed with anti-FLAG antibody and pre-embedding immunogold techniques on the sections adjacent to L5. (A) Representative immuno-EM images from sham control (Sham Ctrl, left) and rhizotomy (right). Immunoparticles for FLAG were detected at intracellular sites (arrowheads in red), plasma membrane (arrowheads in green) in dendritic shafts (Den) of spinal cord neurons, and along the extrasynaptic plasma membrane (arrowheads in blue) of axon terminals (at). Scale bars, 200 nm. (B) The total numbers of immunoparticles from sham control samples (in gray) and rhizotomy (in red) indicate that the expression of TAP-tagged NaV1.7 is down-regulated by about 50% in both presynaptic and postsynaptic terminals after 4 weeks of rhizotomy. (C) Distribution (%) of immunoparticles in both presynaptic and postsynaptic terminals in the rhizotomy model. The numbers of immunoparticles were counted from both presynaptic and postsynaptic terminals. The result shows that there are no significant relative changes of distribution in the rhizotomy model. *P < 0.05, Student’s t test.