Vagal intramuscular arrays (IMAs) in the forestomach appear to transduce tension/stretch through interactions with smooth muscle and intramuscular interstitial cells of Cajal (ICC-IMs), and IMAs are thought to regulate digestive function and inform the brain about such activity. Mice with steel factor or c-Kit mutations have loss of ICC-IMs and IMAs (Burns et al., PNAS, 93, 1996; Fox et al., 1999, SFN mtg; Anat Embryol, 204, 2001). To examine whether loss of the smooth muscle/ICC-IM/IMA signaling pathway is associated with altered ingestive behavior, meal patterns of steel mutants and wild-type mice fed novel pelleted (20mg, Bioserv) or liquid (Isocal, Mead Johnson) diets were monitored for two weeks. Data obtained after feeding patterns stabilized revealed selective changes in short term satiety: meal size in the steel mutants was reduced by 20%, and this was compensated by a 40% increase in meal frequency for solid food; changes were less pronounced on liquid diet. In contrast to these short-term changes...