Dr Sarah J Spencer
Australian Research Council Future Fellow
Address
Department of Physiology
Monash University VIC 3800
Australia
Located
Room F112, Building 13F (Physiology) at Clayton Campus
Tel: +61 3 990 20114
Fax: +61 3 990 52547
Email: Sarah.Spencer@monash.edu
Current lab members:
Sofie Saleh (Research Technician)
Renae Gow (Research Technician)
Former lab members:
Melanie Clarke (Research Assistant)
Elise Usher (Graduated Honours Student)
Kristina Vacy (Graduated Honours Student)
Lauren Bulfin (Undergraduate student)
Background
I conducted my PhD at the University of Queensland under the supervision of Prof. Trevor Day (2001-2004). During this time I acquired an extensive background in the impact of psychological stress on brain pathways that control or contribute to the body’s stress responses. In my first postdoctoral position with Prof. Quentin Pittman at the University of Calgary, Canada (2004-2007), I expanded my work to include a focus on neuroimmune interactions, examining how an immune challenge experienced in early life permanently affects an animal’s ability to combat further infections. Since returning to Australia (2007), I have combined these backgrounds in stress, neuroinflammation, and developmental physiology, to investigate effects of the neonatal environment on stress, immune function, and metabolism in the adult animal.
Research Interests
Research Interests
The early life environment is fundamentally important in dictating the type of adult we become. Stress in early life, exposure to infection, and under- or over-eating can permanently influence how we cope with stress and infection later on and how fast we metabolize food or how much we crave that hamburger. In our lab we investigate how the early life environment influences our physiology to change the way our bodies process food, stress, and challenges to the immune system, and whether these changes are permanent or reversible.
We have several specific focuses:
• How does overfeeding in early life influence long-term physiology?
If an adult animal is fed a high fat diet for three weeks there will be some acute effects but, given a return to normal diet, these will be undetectable in the long-term. Overfeed an animal for three weeks when it is a baby, however, and the effects will last a lifetime. Neonatally overfed rats develop overweight / obesity in as little as seven days. By adulthood, they are bigger, fatter, and have compromised ability to respond to stress and immune challenge. We are currently investigating how the perinatal nutritional environment affects i) propensity to become obese, ii) immune function and iii) stress processing.
Dual energy x-ray absorptiometry (DEXA) pictures
illustrating how neonatal diet influences adult body size in male and female rats.
• Treating stress-related disorders by manipulating diet and body weight
How we respond to stress is intimately connected to our body weight, but the relationship is complex. We have recently shown healthy lean animals respond more efficiently to stress and are less anxious and depressed when faced with a stressful environment. Rats suckled in large litters where they have reduced access to their mothers’ milk stay lean throughout life and have reduced central and behavioural responses to stress. We are in the process of investigating i) if reducing adiposity in adult animals can ameliorate anxiety, depression in stress axis function and ii) what are the mechanisms by which neonatally under-fed rats suppress their stress responses more efficiently.
Schematic diagram of the hypothalamic-pituitary-adrenal axis, the major endocrine arm of the body’s response to stress.
We are investigating how this axis becomes more efficient in lean animals.
• The role of ghrelin in stress
Ghrelin is a gastrointestinal peptide well known for its role in feeding and metabolism. We have recently shown endogenous ghrelin is also able to influence central responses to acute stress and reduce anxiety under high stress conditions. Thus, knockout mice that do not produce ghrelin are more anxious and have greater hypothalamic-pituitary-adrenal axis responses to stress, and this is reversed by exogenous ghrelin injection. We are currently investigating i) if endogenous and exogenous ghrelin suppress stress responses in stress-prone animals, ii) how body weight affects ghrelin’s role in stress, and iii) what are the central pathways involved in ghrelin’s modulation of stress. Ultimately, if we can show ghrelin is effective at reducing stress in at-risk populations, we may be able to treat stress-related disorders with a simple dose of ghrelin.
PhD applicants should have a MSc, 1st class honours or equivalent
All applications and inquires should be sent to Dr Sarah Spencer
Academic Distinctions, Awards and Funding
Monash University Advancing Women in Research Grant (2012)
Australia Research Council (ARC) Future Fellows Fellowship (2011-2015)
National Health and Medical Research Council (NHMRC) Project Grant - Andrews and Spencer (2011-2013)
Monash Research Accelerator Program Award; Recognizing excellence within Monash University (2011-2012)
ARC Discovery Project Grant (2010-12)
NHMRC Equipment Grant - Clarke, Mitchell, Cowley, Tiganis, Oldfield, Rosa, Walker, Lackmann, Watt, Denton, Evans, Kett, Brown, Tilbrook, Smith, Andrews, Spencer, Armitage, Strauss, Simpson, Williams (2009)
Early Career Development Grant – Strategic Grant Scheme (2009)
Endocrine Society of Australia Postdoctoral Fellowship (2009-2010)
Clive and Vera Ramaciotti Foundation Establishment Grant (2008)
NHMRC equipment grant - Denton, Widdop, Oldfield, Evans, Parkington, Drummond, Kett, Black, Watt, Spencer, Rajapakse, Clarke, Schmidt, Bertram (2008)
Collier Charitable Trust equipment grant (2007)
Peter Doherty Fellowship (2007-2011)
Society for Neuroscience Postdoctoral Trainee Award (Canada 2006)
Heart and Stroke Foundation Focus on Stroke Personnel Award (Canada 2006-2008)
Alberta Heritage Foundation for Medial Research (AHFMR) Research Fellowship (Canada 2004-2007)
Brenda Strafford Foundation Award for Alzheimer’s Research (Canada 2004)
AHFMR Recruitment Award (Canada 2004)
University of Queensland Postgraduate Research Scholarship (2001-2004)
First class Honours for studies into 1-EBIO stimulated secretion in the mouse small intestine (New Zealand 2000)
Publications (2007 – present)
Spencer SJ, Xu L, Clarke MA, Lemus M, Reichenbach A, Geenen B, Kozicz T, and Andrews ZB. Ghrelin regulates the hypothalamic-pituitary-adrenal axis and restricts anxiety after acute stress. Biological Psychiatry, Accepted March 2012
Smith JT and Spencer SJ. Pre-weaning over- and under- feeding alters onset of puberty in the rat without affecting kisspeptin. Biology of Reproduction, Accepted February 2012
*Kampe J, *Stefanidis A, Lockie SH, Brown WA, Dixon JB, Odoi A, Spencer SJ, Raven J, and Oldfield BJ. Neural and humoral changes associated with the adjustable gastric band – insights from a rodent model. International Journal of Obesity, Accepted February 01 2012
Clarke MA, Stefanidis A, and Spencer SJ. Postnatal overfeeding leads to obesity and exacerbated febrile responses to lipopolysaccharide throughout life. Journal of Neuroendocrinology, Accepted December 12 2011. doi: 10.1111/j.1365-2826.2011.02269.x
Spencer SJ. Early life programming of obesity: the impact of the perinatal environment on the development of obesity and metabolic dysfunction in the offspring. Current Diabetes Reviews, Accepted October 06 2011. Invited Review
Wixey JA, Reinebrant HE, Spencer SJ, and Buller KM. Efficacy of post-insult minocycline administration to alter long-term hypoxia-ischemia-induced damage to the serotonergic system in the immature rat brain. Neuroscience, 182:184-192 (2011)
Bulfin LJ, Clarke M, Buller KM, and Spencer SJ. Anxiety and hypothalamic-pituitary-adrenal axis responses to psychological stress are attenuated in male rats made lean by large litter rearing. Psychoneuroendocrinology. 36(7):1080-1091 (2011)
Spencer SJ and Tilbrook A. The glucocorticoid contribution to obesity. Stress. 14(3):233-246 (2011)
Spencer SJ, Galic MA, and Pittman QJ. Neonatal programming of innate immune function. Am. J. Physiol. Endocrinol. Metab. 300(1):E11-18 (2011)
Mouihate A, Galic MA, Ellis SL, Spencer SJ, Tsutsui S, and Pittman QJ. Early life activation of Toll-like receptor 4 reprograms neural anti-inflammatory pathways. J. Neurosci. 30(23):7975-7983 (2010)
Spencer SJ, Field E, and Pittman QJ. Neonatal programming by neuroimmune challenge; harmful or beneficial? – effects on responses and tolerance to septic doses of LPS in adult male and female rats. J. Neuroendo. 22(4):272-281 (2010)
Galic MA*, Spencer SJ *, Mouihate A, and Pittman QJ. Postnatal programming of host defense. Integrative and Comparative Biology. 49(3):237-245 (2009). *Co-authors contributed equally to this work
Spencer SJ and Tilbrook A. Neonatal overfeeding alters adult anxiety and stress responsiveness. Psychoneuroendocrinology. 34(9):1133-43 (2009)
Galic MA, Riazi K, Heida JG, Mouihate A, Fournier NM, Spencer SJ, Kalynchuk LE, Teskey GC, and Pittman QJ. Postnatal inflammation increases seizure susceptibility in adult rats. J. Neurosci., 28(27):6904-6913 (2008)
Spencer SJ, Galic MA, Tsutsui M, Pittman QJ, and Mouihate A. Effects of global cerebral ischaemia in the pregnant rat. Stroke, 39:975-982 (2008)
Spencer SJ, Mouihate A, Galic MA, and Pittman QJ. Central and peripheral neuroimmune responses: hypo-responsiveness during pregnancy. J. Physiol., 586(Pt 2):399-406 (2007)
Spencer SJ, Mouihate A, Galic MA, Ellis SL, and Pittman QJ. Neonatal immune challenge does not affect body weight regulation in rats. Am. J. Phys. Reg., 293(1):R581-589 (2007)
Spencer SJ, Mouihate A, and Pittman QJ. Peripheral inflammation exacerbates damage after global ischaemia independently of temperature and acute brain inflammation. Stroke, 38(5):1570-1577 (2007)
Spencer SJ*, Hyland NP*, Sharkey KA, and Pittman QJ. Neonatal immune challenge exacerbates experimental colitis in adult rats: potential role for TNFα. Am. J. Phys. Reg., 292(1):R308-315 (2007)*Co-authors contributed equally to this work
For a full list of publications click here
