Furness Lab ~ Research Projects
Information for prospective honours and PhD students, 2009...
Our main areas of research:
- NEUROBIOLOGY OF PAIN & SENSORY MECHANISMS,
- THE ENTERIC NERVOUS SYSTEM and
- THE CELL BIOLOGY OF NEURONS
On this page you will find:
- GENERAL INFORMATION
- Principal investigators
- Location
- Research program
- Methods
- CHARACTERISATION OF NEURONAL CHANGES ASSOCIATED WITH INFLAMMATION AND ISCHEMIA OF THE GUT
- Project 1 - Changes in ion channel expression in the ENS and sympathetic ganglia as a consequence of inflammation.
- Project 2 - The reactions of enteric neurons to ischemia and their protection.
- Project 3 - The development of inflammation-induced changes in neuronal excitability; can the damage be prevented?
- Project 4 - Gastrointestinal inflammation: neuronal ion channels and motility.
- REGULATION OF DIGESTIVE FUNCTIONS AND FUNCTIONS OF ENTERIC NEURONS
- Project 5 - The roles of clock genes: how does the circadian rhythm influence enteric neurons and digestive function.
- Project 6 - Characterisation and roles of metabolically-sensitive (KATP) channels in neurons.
- Project 7 - Spatiotemporal analysis of intestinal motility patterns evoked by extrinsic nerve stimulation and neuromodulatory drugs.
- THE ROLES OF GHRELIN IN AUTONOMIC CONTROL; IN VIVO PHYSIOLOGY AND DETERMINATION OF SITES OF ACTION
- AUTONOMIC FUNCTION AFTER SPINAL CORD INJURY (SCI): PROGRESS TO THERAPIES
- Project 10 - Changes in physiological control of the colon and manipulation of autonomic responses after spinal cord injury.
- Project 11 - Regulation of blood pressure after spinal cord injury.
- Project 12 - Bladder dysfunction after spinal cord injury.
- HISTOPATHOLOGICAL ANALYSIS
- Project 13 - Histopathology in mutant mice.
- Project 14 - Histological Investigation of Enteric Neuropathy.
GENERAL INFORMATION
Principal investigators
All postdoctoral fellows have full time research positions:
Prof John B Furness
Rm: E238
Ph: 8344 8859/7646
Email: j.furness@unimelb.edu.au
Prof John Furness has substantial research experience in many facets of neuroscience, especially in immunohistochemistry and organ physiology.
Dr Romke Bron
Rm: E327A
Ph: 8344 5811
Email: r.bron@unimelb.edu.au
Dr Romke Bron is a molecular biologist examining inflammation-related changes in enteric neurons.
Dr Peter Kitchener
Rm: E722
Ph: 8344 6746
Email: p.kitchener@unimelb.edu.au
Dr Peter Kitchener is a senior scientist with a very strong background in neuroanatomy and neurophysiology.
Dr Trung Nguyen
Room: E212
Ph: 8344 9994
Email: tvnguyen@unimelb.edu.au
Dr Trung Nguyen is an expert in electrophysiology of enteric neurons and works on the characterisation of ion channels and their regulation in normal and disturbed tissues.
Dr Mark Habgood
Room: N920
Ph: 8344 5741
Email: mhabgood@unimelb.edu.au
Dr Mark Habgood is closely involved in the spinal cord injury projects. He is an expert in stuies of the consequences of spinal cord injuries in animal models.
Dr Kulmira Nurgali
Rm: N504C
Ph: 8344 6669
Email: k.nurgali@unimelb.edu.au
Dr Kulmira Nurgali is an electrophysiologist specialising in functional changes in the inflamed gut.
Location
You are welcome to visit us in our lab on the Ground Floor of the East Wing of the Medical (Tri-radiate) Building.
Research program
Our research program combines structural, physiological, pharmacological and neurochemical studies of the enteric nervous system, and visceral afferent (sensory) neurons. Members of our laboratory have backgrounds in molecular biology, physiology, biochemistry, cell biology, pharmacology and physics. We are also involved in drug discovery research in these areas. We have a strong interest in ion channels and their regulation.
Methods
We use a wide variety of methods including immunohistochemistry, confocal microscopy, molecular biology, patch clamp recording, intracellular microelectrode recording, retrograde neuronal tracing, in vitro and in vivo reflex studies, biophysical analysis of neuron properties, whole animal physiology, behavioural testing, and pharmacological analysis in vivo and in vitro.
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Projects 1-4: Characterisation of neuronal changes associated with inflammation and ischemia of the gut
We study the consequences of inflammation and ischemia on the enteric nervous system, (ENS). inflammation is relevant to the common and debilitating disorder, irritable bowel syndrome (IBS), which is often a post-inflammatory disorder, and to inflammatory bowel disease (IBD). Ischemia causes derangements of gut function and is a complication in transplant surgery.
We have found distinct changes in neuronal behaviour after inflammation, which may well explain many of the symptoms typical of IBS and IBD, such as diarrhoea or constipation. Our electrophysiological studies have indicated that several of the different types of neurons that make up the ENS become hyper-excitable, as a consequence of inflammation.
Whereas the overt effects of inflammation or ischemia (e.g. tissue damage, recruitment of various immune cells) appear to be short-lived, the changes in neuronal behaviour have been shown to be long-lasting. The reasons for the continued misbehaviour of the ENS neurons in the absence of an obvious trigger are not clear. One possibility is that exposure to an environmental (i.e. inflammatory) cue has triggered a (semi-permanent) secondary differentiation of the neurons, which has been imprinted in neuronal gene expression. Alternatively, it is possible that there is a continued presence of a covert inflammatory reaction.
Project 1: Changes in ion channel expression in the ENS and sympathetic ganglia as a consequence of inflammation.
Dr Romke Bron, Ms Billie Hunne, Ms Michelle Thacker, Ms Louise Pontell, Ms Kirsty Turner, Dr Kulmira Nurgali, Prof John Furness
In this project we are investigating effects of inflammation on the molecules that control the excitability of neurons. Ileitis will be induced using a micro-surgical procedure, in which TNBS will be injected directly into the ileum of sedated guinea-pigs. At different time-points after surgery tissue will be taken for analysis. We will use quantitative RT-PCR to detect changes in the levels of expression of ion channels (voltage-activated Ca2+ and Na+ channels, K+ channels) and inflammatory responses. In addition, we will map the expression of channels to the different neuronal subclasses, using a combination of in situ hybridisation and immunohistochemistry.
Project 2: The reactions of enteric neurons to ischemia and their protection.
Ms Leni Rivera, Ms Michelle Thacker, Ms Louise Pontell, Dr Romke Bron, Ms Billie Hunne, Prof John Furness
The changes caused by ischemia are recognised as important in causing gut dysfunction, but very little is known about effects at a cell level. We have recently found that effects on neurons are substantial and type specific, for example the nitric oxide neurons are swollen to almost double their normal volume. Moreover, there is a large, but generally unrecognised, inflammatory reaction associated with ischemia. A substantial part of the damage appears to be exerted by free-radical formation, including the production of nitric oxide. In this project, we are investigating the mechanisms behind the damage, and are using transgenic animals and pharmacological interventions to investigate protection against ischemic injury.
Project 3: The development of inflammation-induced changes in neuronal excitability; can the damage be prevented?
Dr Kulmira Nurgali, Ms Michelle Thacker, Dr Romke Bron, Prof John Furness
Abdominal pain and diarrhoea, which are major symptoms of intestinal inflammation, are due to complex changes in the gut including altered properties of enteric neurons. It is largely unknown how changes are initiated by inflammation, although it is probably early in the process of neuronal change that an intervention could be successful. The aims of this study are to investigate at which stages of inflammation changes in neuronal excitability occur and to define which types of neuron are most affected by inflammation.
You will be involved in animal surgery to induce inflammation in the small intestine and immunohistochemical and molecular studies of the enteric neurons and their processes. Studies will be done at 3 to 24 hours after the induction of inflammation. Intracellular recordings from myenteric neurons and histological assessments will be done in parallel to correlate functional, morphological and immunohistochemical changes in neurons. The effects of neuroprotective treatment will be tested.
Project 4: Gastrointestinal inflammation: neuronal ion channels and motility.
Dr Kulmira Nurgali, Ms Melina Ellis, Prof Joel Bornstein, Ms Dorota Ferens, Prof John Furness
Irritable Bowel Syndrome (IBS) is an important clinical and community problem. It commonly follows gastrointestinal inflammation and is characterized by pain and motility disturbances. In animal models using TNBS to induce inflammation we found that changes in specific types of Na+, K+ and Ca2+ channels occur in myenteric neurons. The aim of this project is to investigate how these changes in the enteric nervous system affect gut motility.
You will be involved in animal surgery to induce inflammation in the small intestine. The inflamed ileum will be taken to study its contractile activity at 3 h, 24 h and day 7 after the induction of inflammation. You will compare the effects of specific agonists and antagonists of the ion channels on the motility in control, sham-operated and inflamed ileum.
Projects 5-6: Regulation of Digestive Functions and Functions of Enteric neurons
Project 5: The roles of clock genes: how does the circadian rhythm influence enteric neurons and digestive function.
Dr Romke Bron, Ms Billie Hunne, Prof John Furness
Daily (circadian) rhythms in cell activity direct the functions of many organs. Disruption of these rhythms by shift work or through jetlag compromises health. In addition to such disruptions caused by changes in activity relative to the day, there are rhythm generators in the digestive system that respond to meals. Although it is known that irregular meals can be unhealthy, there is very little known of the activities of circadian mechanisms in the digestive system. This project will determine the oscillations of clock genes of the gastrointestinal tract and the factors involved in setting digestive time.
Project 6: Characterisation and roles of metabolically-sensitive (KATP) channels in neurons.
Dr Trung Nguyen, Ms Louise Pontell, Ms Billie Hunne, Dr Romke Bron, Prof John Furness
ATP sensitive potassium channels (KATP) channels are monitors of the metabolic states of neurons. By re-setting their activity, they can protect against metabolic damage. The channels are found at cell surfaces and in mitochondria. In this project, we will determine the effects of openers and closers of KATP channels of intrinsic sensory neurons of the small intestine, using electrophysiological measurements and live cell imaging.
Project 7: Spatiotemporal analysis of intestinal motility patterns evoked by extrinsic nerve stimulation and neuromodulatory drugs.
Dr Peter Kitchener, Dr Tony Shafton and Prof John Furness
The process of digestion is dependent on patterns of contractile activity in the gastrointestinal tract. This activity can broadly be seen to be either propulsive movement of luminal contents along the intestine, or mixing movements that allow breakdown and absorption. We have developed methods to simultaneously monitor circular and longitudinal contractile activity of regions of the intestine in vivo, and wish to apply these methods to examine the detailed nature of spontaneous activity, and the activity evoked by stimulation of extrinsic nerves that innervate the intestine, and the effect of drugs known to alter the pattern of intrinsically generated motility.
Projects 8-9: The Roles of Ghrelin in Autonomic Control; In vivo Physiology and determination of sites of action
We have discovered that the hormone ghrelin, best known for roles in growth hormone release and stimulation of eating, has important functions in controlling autonomic organs from the spinal cord level and probably from the brain stem. In linked projects, we are investigating the roles of ghrelin using in vivo recording from rats, and the distributions of sites of action using in situ hybridisation and activity-dependent labelling of neurons.
Project 8: Physiological Analysis of Actions of Ghrelin in vivo.
Ms Dorota Ferens, Dr Lei Yin, Dr Romke Bron and Prof John Furness
These studies involve application of drugs that specifically target ghrelin receptors through the peripheral circulation or directly to the spinal cord. Responses of the circulation, of the heart, the gastrointestinal tract and the urinary bladder are measured in separate sub-projects. Sites of action are analysed by selective nerve lesions, pharmacological manipulation and correlation with morphological identification of activated neurons. In this project, you will learn how to assess the functions of organ systems in live animals, and how to conduct pharmacological investigations, in vivo.
Project 9: Organisation of the Ghrelin system in the spinal cord and medulla.
Dr Lei Yin, Ms Dorota Ferens, Dr Romke Bron and Prof John Furness
This work aims to determine the organisation of the nerve circuits in which ghrelin participates. We will use in situ hybridisation to localise ghrelin receptors and the ghrelin specific enzyme, ghrelin-o-acyl transferase. The neurons that express these genes will be identified by immunohistochemical double-staining, pathway tracing and activity-dependent c-fos localisation.
Projects 10- 12: Autonomic function after spinal cord injury (SCI): Progress to therapies
To most observers, the dominant impact of spinal cord injury (SCI) is impaired mobility. However, it is impairment of control of internal functions, through the autonomic nervous system (ANS) that socially isolates, increases dependence, precipitates hospital re-admission and causes premature death. This program of research applies a combination of unique clinical and preclinical approaches to develop novel treatments of ANS dysfunction in SCI.
Project 10: Changes in physiological control of the colon and manipulation of autonomic responses after spinal cord injury.
Ms Dorota Ferens, Ms Kirsty Turner, Dr Mark Habgood, Dr Romke Bron, Prof John Furness
The daily need for assistance with defecation in spinal injured patients is unpleasant, time-consuming and expensive for patient and carer. Moreover, it does not avert the single most socially crippling consequence of SCI - uncontrolled defecation. In this project we are studying the mechanisms that lead to bowel dysfunction in SCI. We have discovered a novel pharmacological method to trigger colorectal emptying. This project will test in animal models this and other therapies for treating injured patients.
Project 11: Regulation of blood pressure after spinal cord injury.
Prof John Furness, Assoc Prof Doug Brown, Dr Christopher O’Callaghan
This project is in collaboration with clinical colleagues and is suitable for a medical or nursing graduate. Loss of blood pressure control means loss of a fundamental of bodily regulation – maintaining brain blood flow when erect. SCI patients have abnormally high blood pressure when lying down and low blood pressure to the point of losing consciousness when made erect. We have successfully trialled in patients a treatment that we will further develop for blood-pressure control in SCI, and which will reduce the high night-time blood pressure and blood pressure drop and fainting when patients become upright in the morning.
Project 12: Bladder dysfunction after spinal cord injury.
Prof John Furness, Ms Kirsty Turner, Dr Mark Habgood, Dr Romke Bron
Loss of neural influence on the bladder lining and breakdown of its barrier function causes elevated rates of urinary tract infections in SCI; this is a major cause of hospital re-admission and loss of functional independence. This project will investigate the mechanisms of barrier breakdown and aims to develop novel treatments for this neuropathic cystitis following the identification of reasons for barrier breakdown and of therapeutic targets.
Projects 13-14: Histopathological analysis
Project 13: Histopathology in mutant mice.
Ms Tina Cardamone, Ms Louise Pontell, Ms Kirsty Turner, Prof John Furness
One of the most important skills needed for the analysis of mutant mice, where the mutation is not known, or the consequences of mutation are unexpected, is histopathological analysis. The skills to do this type of study are much in demand. In this project, you will be set the task of conducting histopathological analysis of three different mutants. You will learn how to prepare tissues, how to conduct a systematic analysis, how to use sophisticated imaging hardware and software and how to report histopathological results.
Project 14: Histological Investigation of Enteric Neuropathy.
Prof John Furness, Dr Helen Irving, Ms Tina Cardamone, Ms Louise Pontell, Ms Billie Hunne, Ms Kirsty Turner, Dr Romke Bron
Our investigation of animal models of enteric nervous system disorders has identified a number of possible therapeutic targets. However, whether these targets are expressed by enteric neurons, and whether their expression is changed in inflammatory bowel disease is unknown. In this project we will compare ostensibly normal and pathological intestine, using histology, immunohistochemistry, in situ hybridisation and PCR techniques. Ganglia will be isolated using laser capture microdissection.