Figure 9.
CART(55–102) immunolabeling of the dorsovagal complex of metabolically challenged Nav1.8-Cre-ChR2-YFP mice. A, B, C, CART-positive (Alexa Fluor 594) perikarya and fibers of various origins were observed throughout the NTS and AP. We noticed a trend toward increased immunoreactivity in the fasted groups. However, our estimates (see Fig. 6) indicate that the levels of CART in vagal afferents remained unchanged across feeding conditions. D, E, F, CART immunoreactivity combined with endogenous ChR2-YFP fluorescence. G, CART was very abundant in the AP. In particular, many YFP-labeled varicosities of vagal origin were enriched for CART. However, we also observed CART immunoreactivity that was not contained in ChR2-YFP–labeled fibers. H, High magnification of the distribution of CART immunoreactivity in the vagal fibers of the AP in a single optical plan. Of note, CART frequently labeled the cytoplasm contained within the YFP-labeled varicosities, which are indicated by arrowheads. Scale bars, 60 μm in A, applies to B–F; 15 μm in G; 5 μm in H.