In Vitro Recording of Mesenteric Afferent Nerve Activity in Mouse Jejunal and Colonic Segments

Sara Nullens; Annemie Deiteren; Wen Jiang; Christopher Keating; Hannah Ceuleers; Sven Francque; David Grundy; Joris G. De Man; Benedicte Y. De Winter

doi:10.3791/54576

Method Article

In Vitro Recording of Mesenteric Afferent Nerve Activity in Mouse Jejunal and Colonic Segments

11.1K views

⸱

DOI:

10.3791/54576

⸱

October 25th, 2016

Sara Nullens¹ , Annemie Deiteren² , Wen Jiang³ , Christopher Keating⁴ , Hannah Ceuleers¹ , Sven Francque⁵ , David Grundy³ , Joris G. De Man¹ , Benedicte Y. De Winter¹

¹Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, ²Visceral Pain Group, Discipline of Medicine, University of Adelaide, ³Department of Biomedical Sciences, University of Sheffield, ⁴Department of Pharmacy, Pharmacology and Postgraduate Medicine, University of Hertfordshire, ⁵Department of Gastroenterology and Hepatology, Antwerp University Hospital

Summary

Mesenteric afferent nerves convey information from the gastrointestinal tract towards the brain regarding normal homeostasis as well as pathophysiology. Gastrointestinal afferent nerve activity can be assessed by mounting isolated intestinal segments with attached afferent nerves into an organ bath, isolating the nerve, and assessing basal as well as stimulated activity.

Abstract

Afferent nerves not only convey information concerning normal physiology, but also signal disturbed homeostasis and pathophysiological processes of the different organ systems from the periphery towards the central nervous system. As such, the increased activity or 'sensitization' of mesenteric afferent nerves has been allocated an important role in the pathophysiology of visceral hypersensitivity and abdominal pain syndromes.

Mesenteric afferent nerve activity can be measured in vitro in an isolated intestinal segment that is mounted in a purpose-built organ bath and from which the splanchnic nerve is isolated, allowing researchers to directly assess nerve activity adjacent to the gastrointestinal segment. Activity can be recorded at baseline in standardized conditions, during distension of the segment or following the addition of pharmacological compounds delivered intraluminally or serosally. This technique allows the researcher to easily study the effect of drugs targeting the peripheral nervous system in control specimens; besides, it provides crucial information on how neuronal activity is altered during disease. It should be noted however that measuring afferent neuronal firing activity only constitutes one relay station in the complex neuronal signaling cascade, and researchers should bear in mind not to overlook neuronal activity at other levels (e.g., dorsal root ganglia, spinal cord or central nervous system) in order to fully elucidate the complex neuronal physiology in health and disease.

Commonly used applications include the study of neuronal activity in response to the administration of lipopolysaccharide, and the study of afferent nerve activity in animal models of irritable bowel syndrome. In a more translational approach, the isolated mouse intestinal segment can be exposed to colonic supernatants from IBS patients. Furthermore, a modification of this technique has been recently shown to be applicable in human colonic specimens.

Introduction

Sensory signaling and pain perception is a complex process that results from an intricate interplay between afferent nerves, spinal neurons, ascending and descending facilitatory and inhibitory pathways and several different brain regions. As such, changes at one or more of these levels may result in altered sensory signaling and visceral pain in disease states. To study all these different aspects of sensory signaling multiple techniques have been developed ranging from single cell experiments (e.g., calcium imaging on neurons) to whole animal models (e.g., behavioral responses such as the visceromotor response). The technique described in this pape....