FIG. 1.
Differential topography of 5-HT1AR detected with an intracellular (ICL3) and an extracellular (ECL2) epitope-recognizing antibody. Panels a–c are images projected from 30 single plane 1 μm confocal images of L4 lamina IX neurons in a control rat labeled for both ECL2 and ICL3 antibodies, whereas d–g are single plane (1 μm) images of an L4 control motoneuron. The ECL2 antibody stained primarily the axon hillock and initial segment (arrows in b, c, e, f, and g) of the axon, while the cell body (double arrows in b) showed weak, diffuse staining. The ICL3 antibody detected 5-HT1AR proteins primarily on proximal dendrites (asterisks in a, c, d, f, and g), and on the cell body (arrowheads in a, c, d, f, and g). Motoneurons were identified by HSP27 (f and g) (scale bars for a–c = 20 μm, and d–g = 10 μm). (Color image is available online at www.liebertpub.com/jon.)