Fig. 7.

YFP-immunoreactive innervation of somatic motor neurons. Two-color immunoperoxidase staining for YFP (black) and ChAT (brown) in transverse sections through the thoracic and lumbar spinal cord. (A–C) At all segmental levels, lamina IX contains a moderate number of black varicose YFP-immunoreactive axons. Micrographs in montages: A, 3; B and C, 5. Scale bars: A and B, 100 μm; C, 250 μm. (D–I) Nevertheless, only rare, brown ChAT-immunoreactive somatic motor neurons receive close appositions (arrows) from black YFP-immunoreactive varicosities. Appositions from YFP-immunoreactive boutons do occur on the dendrites of somatic motor neurons (C–E). However, in most cases, YFP-containing varicosities appose the cell bodies of somatic motor neurons (F–I). LE, lumbar enlargement. Micrographs in montages: D-F & H, 3; G, 2; I, 5. Scale bars: D, 50 μm; E–I, 20 μm. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)