Figure 7.

Deletion of TPH2 reduces the numbers of GABAergic, nitrergic, and CGRP-expressing neurons but does not affect the density of sympathetic terminal axons in the ENS; the immunoreactivities of TH and GABA are not coincident. The immunoreactivities of HuC/D (total neurons), TH, and GABA were demonstrated simultaneously in LMMP preparations of WT (A–D) and TPH2KO (E–H) mice. A, WT mouse; HuC/D; B, WT mouse; TH. C, WT mouse; GABA. D, Merged image. E, TPH2KO mouse; HuC/D; F, TPH2KO mouse; TH. G, TPH2KO mouse; GABA. H, TPH2KO mouse; merged image. Whole-mount preparations were also used to demonstrate the immunoreactivities of nNOS in the myenteric (I, J) and CGRP in the submucosal plexus (K, L). I, WT mouse; nNOS. J, TPH2KO mouse; nNOS. K, WT mouse; CGRP. L, TPH2KO mouse; CGRP. Note that the density of TH-immunoreactive sympathetic terminals in the myenteric plexus is similar in WT (B) and TPH2KO (F) mice. Scale bars: A–H, 25 μm; I–L, 50 μm.