Fig. 2. Neurogenic motor patterns in animals.

Images a–c show examples of neurogenic motor patterns expressed as spatiotemporal maps showing changes in diameter (DMaps) of the excised colon of different animal species in vitro. Two main neurogenic motor patterns have been recognized. The first is neural peristalsis (consensus term) triggered by distension, which was described as propulsive contractions in the guinea pig distal colon³³ (part a) and subsequently as long-distance contractions in the rabbit colon²¹ (part b). The second motor pattern present in the rabbit proximal colon consists of very slowly propagating contractions, representing the neural colonic motor complex²⁰ (part c) and subsequently as haustral boundary contractions or progression (part b). In the complete mouse colon¹⁹⁹ (part d) and in the guinea pig distal colon⁸¹ (part e) colonic motor complexes occur in distended segments. Neurogenic peristalsis is triggered and sustained by content, whereas the colonic motor complexes are generated as regular motor activity slowly traversing long segments of colon or appearing even in the absence of any propulsion of contents. Part a adapted with permission from ref.³³, The American Physiological Society. Part b adapted with permission from ref.²¹, The American Physiological Society. Part c adapted with permission from ref.²⁰, The American Physiological Society. Part d adapted with permission from ref.¹⁹⁹, Wiley-VCH. Part e adapted with permission from ref.⁸¹, Wiley-VCH.