Fig. 13.
Analysis of Fos immunoreactivity supports the idea that CGRP-mediated neurotransmission is required for the spread of excitation in the submucosal plexus after the delivery of a mechanical stimulus to the mucosa. Puffs of N2 were used to excite submucosal neurons as described previously (Kirchgessner et al., 1992). A, There is no Fos immunoreactivity in the nuclei of the neurons in a submucosal ganglion of a nonstimulated preparation.B, Much Fos immunoreactivity is found in a submucosal ganglion after the mucosa had been stimulated under control conditions with N2 puffs for 30 min. C, No Fos-immunoreactive nuclei can be found in submucosal ganglia when the mucosa was stimulated with N2 puffs for 30 min (as inB) but in the presence of the CGRP antagonist hCGRP8–37. Scale bar, 50 μm.