Abstract #49

# 49
The brain within the gut—Activation of enteric cells and sensory neurons.
John B. Furness*1, David M. Bravo2, Jeremy J. Cottrell1, Frank R. Dunshea1, 1University of Melbourne, Parkville, Australia, 2InVivo Animal Nutrition & Health, Talhouët, Saint-Nolff, France.

For optimal digestive efficiency, the contents of the gastrointestinal tract need to be detected and the information needs to be conveyed to control systems: the gut endocrine system, the nervous system and the immune and tissue defense systems. The contents include nutrients, products of digestion, bacteria, viruses, fungi and potentially injurious substances in foods. Sensory neurons that innervate the gut lining detect hormones released from enteroendocrine cells (EEC) and also detect other signals, for example cytokines and other substances released when the gut is inflamed, and contractile activity of the gut. There are 4 classes of enteric sensory neurons, intrinsic primary afferent neurons (IPANs), with cell bodies in the gut wall, vagal primary afferent neurons, spinal primary afferent neurons and intestinofugal neurons, and within each class there are subclasses that detect different sensory signals. From a comparative point of view, the functioning of the enteric nervous system (ENS) is similar between species, although there are some differences in its organization, as will be discussed. The ENS works in concert with CNS reflex and command centers to control digestive function, so it cannot be considered in isolation. There is bidirectional information flow between the ENS and CNS. The major type of sensory ENS neuron is the IPAN. These neurons have distinctive shapes and electrophysiological characteristics, similar to primary afferent neurons of dorsal root ganglia. Their axons in the mucosa sense the chemical environment of the lumen and mucosal distortion. They also detect toxins (they are nociceptive neurons). Other processes of the neurons are sensitive to muscle movement. Their outputs are to other enteric neurons (interneurons and motor neurons) and to intestinofugal neurons. The major functions they control are gut movements, water and electrolyte secretion and blood flow.

Key Words: enteric nervous system, sensory neurons

Speaker Bio
John Furness is Professor of Anatomy and Neuroscience at the University of Melbourne.  He leads the Digestive Physiology and Nutrition Laboratory.

His laboratory has worked for many years on the enteric nervous system and he continues studies on the organisation and functions of the ENS.  The current emphasis of his work is on the relationships between diet, environment and gut health, and their implications for animal production and for human well-being.  
He is best known for his work in unravelling the intrinsic circuits of the enteric nervous system: recently reviewed in Nature Reviews, Gastroenterology, for the chemical coding hypothesis, and for the discovery and identification of sensory neurons intrinsic to the digestive tract.  

Another focus of his current work is on the investigation of therapeutic approaches to solving autonomic dysregulation that is consequent on spinal cord injury.  He is the leader of the Autonomic Spinal Cord Injury Program, sponsored by the Transport Accident Commission.  Therapeutic approaches to solving the dysregulation of bowel function that follows SCI are being addressed through animal proof of principle studies and clinical investigations using centrally penetrant ghrelin receptor agonists.
He also directs the Histopathology and Organ Pathology Service, which investigates the histopathology of transgenic and other experimental animals.  HOPS utilises virtual slide technology and the analysis of large histopathology image files. 

He is one of the most highly cited Australian scientists.  He has published over 300 papers related to Digestive Physiology.  Google Scholar (June 2015) gives his h-index as 95, including 31,384 citations overall.
 
Honours and Awards include:
Fellow of the Australian Academy of Science, 1989
Davenport Medal in Digestive Physiology, American Physiological Society
Grossman Medal and Lecture, UCLA
Fellow, Academy of Science of Bologna (L'accademia delle scienze dell'istituto di Bologna), 2005
Centenary Medal, Govt of Australia, 2003
 
Recent publications:
Furness JB (2012) The enteric nervous system and neurogastroenterology. Nat. Rev. Gastroenterol. Hepatol. 9:286-294
Furness JB, Callaghan B, Rivera LR, Cho HJ (2014) The enteric nervous system and gastrointestinal innervation: Integrated local and central control. In: Lyte M, Cryan JF (eds) Microbial Endocrinology: The Microbiota-gut-brain axis in health and disease. Springer, New York, pp 39-71
Furness JB, Poole DP (2012) Involvement of gut neural and endocrine systems in pathological disorders of the digestive tract. J. Anim. Sci. 90:1203-1212
Furness JB, Rivera LR, Cho H-J, Bravo DM, Callaghan B (2013) The gut as a sensory organ. Nat. Rev. Gastroenterol. Hepatol. 10:729-740