Flinders University

About: Flinders University is a education organization based out in Adelaide, South Australia, Australia. It is known for research contribution in the topics: Population & Health care. The organization has 12033 authors who have published 32831 publications receiving 973172 citations. The organization is also known as: Flinders University of South Australia.

Calbindin neurons of the guinea-pig small intestine: quantitative analysis of their numbers and projections.

Abstract: The distribution of nerve cells with immunoreactivity for the calcium-binding protein, calbindin, has been studied in the small intestine of the guinea-pig, and the projections of these neurons have been analysed by tracing their processes and by examining the consequences of nerve lesions. The immunoreactive neurons were numerous in the myenteric ganglia; there were 3500±100 reactive nerve cells per cm2 of undistended intestine, which is 30% of all nerve cells. In contrast, reactive nerve cells were extremely rare in submucous ganglia. The myenteric nerve cells were oval in outline and gave rise to several long processes; this morphology corresponds to Dogiel's type-II classification. Processes from the cell bodies were traced through the circular muscle in perforating nerve fibre bundles. Other processes ran circumferentially in the myenteric plexus. Removal of the myenteric plexus, allowing time for subsequent fibre degeneration, showed that reactive nerve fibres in the submucous ganglia and mucosa came from the myenteric cell bodies. Operations to sever longitudinal or circumferential pathways in the myenteric plexus indicated that most reactive nerve terminals in myenteric ganglia arise from myenteric cell bodies whose processes run circumferentially for 1.5 mm, on average. It is deduced that the calbindin-reactive neurons are multipolar sensory neurons, with the sensitive processes in the mucosa and with other processes innervating neurons of the myenteric plexus.

Post-inflammatory colonic afferent sensitisation: different subtypes, different pathways and different time courses.

Abstract: Objective: Intestinal infection evokes hypersensitivity in a subgroup of IBS patients long after healing of the initial injury. TNBS-induced colitis in rodents likewise results in delayed maintained hypersensitivity - regarded as a model of some aspects of IBS. The colon and rectum have a complex sensory innervation, comprising 5 classes of mechanosensitive afferents in the splanchnic and pelvic nerves. Their plasticity may hold the key to underlying mechanisms in IBS. Our aim was therefore to determine the contribution of each afferent class in each pathway towards post-inflammatory visceral hypersensitivity. Design: TNBS was administered rectally and mice were studied after 7 (acute) or 28 (recovery) days. In vitro preparations of mouse colorectum with attached pelvic or splanchnic nerves were used to examine the mechanosensitivity of individual colonic afferents. Results: Mild inflammation of the colon was evident acutely that was absent at the recovery stage. TNBS treatment did not alter proportions of the 5 afferent classes between treatment groups. In pelvic afferents little or no difference in response to mechanical stimuli was apparent in any class between control and acute mice. However, major increases in mechanosensitivity were recorded from serosal afferents in mice after recovery, while responses from other subtypes were unchanged. Both serosal and mesenteric splanchnic afferents were hypersensitive at both acute and recovery stages. Conclusions: Colonic afferents with high mechanosensory thresholds contribute to inflammatory hypersensitivity, but not those with low thresholds. Pelvic afferents become involved mainly following recovery from inflammation, whereas splanchnic afferents are implicated during both inflammation and recovery.