Shawn Hayley

Research Interest

My research is focused upon how interactions between the brain and immune system may influence the development of psychiatric and neurological conditions. In particular, how stressors impact upon neuro-immune communication to promote emotional and behavioural disturbances. Current projects are also exploring how environmental factors and immune insults may cause brain inflammation that contributes to neurodegeneration.

Neuroimmune interactions

This facet of my research focuses upon mechanisms through which the brain and immune system communicate with each other. In this respect, protein messengers, called cytokines, released from immune cells may inform the brain of infectious/inflammatory events. Likewise, stressors or other centrally acting factors may shape the immune response by altering cytokine activity. Such bi-directional communication may help explain how various illness (e.g. infections, heart disease, stroke) are influenced by stressors and other life experiences.

Molecular mechanisms of stress

Many types of stressors exist that range from primarily psychological in nature (psychogenic) to those that impact directly upon physical aspects of individuals (neurogenic). Since cytokines have neurochemical and behavioural effects reminiscent of traditional stressors, these have been proposed to act as systemic stressors. Current work examines the underlying molecular pathways (e.g. MAP kinases, NFkB) that be activated by stressors and immune system factors (particularly cytokines). Psychogenic stressors may cause emotional and behavioural disturbances by stimulating cytokine activity in conjunction with these molecular pathways.

Stressor-cytokine sensitization 

Current focus upon the neuronal mechanisms responsible for the long-term effects of stressor and cytokine exposure. Brain pathways may become hyper-sensitive to environmental insults after experiencing certain combinations of stress and excessive immune activation. This sensitization phenomenon may help explain how behavioural and neuronal pathology are related to the accumulating effects of environmental insults throughout life.

Inflammatory aspects of neurodegenerative diseases

Parkinson’s, Alzheimer’s, multiple sclerosis and other neurodegenerative diseases all have a strong neuroinflammatory component. My present research seeks to determine the role of cytokines and other inflammatory factors (e.g. prostaglandins, nitric oxide) in these conditions. Particular attention is devoted to the possibility that brain inflammation related to environmental factors (e.g. pesticides, viral infections), might shape the onset and development of Parkinson’s disease in certain predisposed individuals.

List of Recent Publications

Papers in Refereed Journals

Anisman H, Turrin N, Merali Z & Hayley S (2003). Neurochemical Sensitization Associated with Systemic administration of Tumor Necrosis Factor- : Adjuvant Action in Combination with Bovine Serum Albumin. J. Neuroimmunol., submitted.

Hayley S, Crocker SJ, Smith P, Shree T & Park DS (2003). Mice lacking the tumor necrosis factor- or Fas receptors are resistant to MPTP induced death of dopaminergic neurons. J. Neurosci., submitted.

Hayley S, Kelly OP & Anisman (2003). Corticosterone changes in response to stressors, acute and protracted actions of tumor necrosis factor- , and lipopolysaccharide treatments in mice lacking the tumor necrosis factor- p55 receptor gene. Neuroimmunomodulation, submitted.

Smith, P, Crocker SJ, Jackson-Lewis V, Prezborski S, Hayley S, Slack R, & Park DS (2003). Neuroprotective effects of CDK5 in the MPTP model of Parkinson’s disease. Proc. Natl. Acad. Sci., in press.

Crocker SJ, Smith P, Jackson-Lewis V, Hayley S, Prezborski S, Lambda W, Slack R & Park DS (2003). Role of calpain in MPTP-induced dopamine neuron loss and behavioural impairment in mice. J. Neurosci., 23, 4081-4091. Anisman H, Merali Z & Hayley S (2003). Sensitization associated with stressors and cytokine treatments. Brain Behav. Immun., 17, 86-93.

Michaud DS McLean J, Keith SE Ferrarotto C, Hayley S, Anisman H & Merali Z (2003). Strain differences in neurochemical and neuroendocrine responses to an acute audiogenic stressor in male Fischer 344 and Lewis rats. Neuropsychopharmacology, 28, 1068-1081.

Hayley S, Merali Z & Anisman (2003). Stress and cytokine-elicited neuroendocrine and neurotransmitter sensitization: implications for depressive illness. Stress, 6, 19-32.

Hayley S, Merali Z & Anisman H (2002). The acute and sensitization effects of tumor necrosis factor-a: implications for immunotherapy as well as psychiatric and neurological conditions. Acta Neuropsychiat., 14, 322-335.

Anisman H, Hayley S, Turrin N & Merali Z (2002). Stress, cytokines and depression. Inter. J. Neuropsychiat. 5, 357-373.

Hayley S, Kelly O & Anisman H (2002). Murine tumor necrosis factor- sensitizes plasma cortcisoterone and manifestation of shock: Modulation by histamine. J. Neuroimmunol., 131, 60-69. Hayley S, Wall P & Anisman H (2002). Sensitization to the Neuroendocrine, Central Monoamine and Behavioral Effects of murine Tumor Necrosis Factor- : Peripheral and central mechanisms. Eur. J. Neurosci., 15, 1061-1076.

Anisman H, Kelly O, Hayley S, Borowski TB, Merali Z & McIntyre DC (2001). Acoustic startle and fear potentiated startle in rats selectively bred for fast and slow kindling rates: Relation to monoamine activity. European Journal of Neuroscience, 12, 4405-4416.

Hayley S, Merali Z & Anisman H (2001). Central monoamine activity in genetically distinct strains of mice following a psychogenic stressor: effects of predator exposure. Brain Research, 892, 293-300. Anisman H, Hayley S, Kelley O, Borowski TB & Merali Z (2001). Psychogenic, neurogenic and systemic stressor effects on plasma corticosterone and behavior: mouse strain-dependent outcomes. Behavioral Neuroscience, 115, 443-454.

Hayley S, Lacosta S, Merali Z, van Rooijen N & Anisman H (2001). Central Monoamine and Plasma Corticosterone Changes Induced by a Bacterial Endotoxin: Sensitization and Cross-sensitization Effects. European Journal of Neuroscience, 13, 1155-1165.

Hayley S, Staines W, Merali Z & Anisman (2001). Time-dependent sensitization of corticotropin-releasing hormone, arginine vasopressin and c-fos immunoreactivity within the mouse brain in response to tumor necrosis factor- . Neuroscience, 106, 137-148.

Brebner K, Hayley S, Zacharko RM, Merali Z & Anisman H. (2000). Synergistic effects of Interleukin interleukin-6 and Tumor Necrosis Factor- Central monoamine, corticosterone and behavioral variations. Neuropsychopharmacology, 22, 566-580.

Hayley S, Brebner K, Lacosta S., Merali Z & Anisman H. (1999). Sensitization effects of Tumor Necrosis Factor-a: neuroendocrine, central monoamine and behavioral variations. Journal of Neuroscience, 19 (13), 5654-5665.

Lu Z W, Hayley S, Ravindran A V, Merali Z & Anisman H. (1999). Influence of psychosocial, psychogenic and neurogenic stressors on several aspects of immune functioning in mice. Stress, 3 (1), 55-70.

McIntyre D C, Kent P, Hayley S, Merali Z & Anisman H. (1999). Influence of psychogenic and neurogenic stressors on neuroendocrine and central monoamine activity in fast and slow kindling rats. Brain Research, 840, 65-74.

Chapters in Books

Hayley S, Merali Z & Anisman H (2003). Cytokine-elicited sensitization: neuroendocrine, neurotransmitter and behavioral responses In: Z. Kronfol (Ed). Cytokines and mental health. Kluwer Academic, Norwell, MA, pp. 225-258.

Anisman H, Hayley S & Merali Z (2002). Parallels between the behavioral and neurochemical effects of cytokines and stressors. In: R. Kvetnansky and D. Jezova (Eds). Seventh annumal syposium on catecholamines and other neurotransmitters in stress. Smolenice Castle, Slovakia. In press.

Anisman H & Hayley S (2003). Tumor Necrosis Factor- Affects Central neurotransmission and may contribute to neuropsychiatric disorders and neurodegenerative processes. Encyclopedia of Neuroscience, 3rd Edition.

Anisman H., Hayley S., Ravindran A.V., Merali Z. & J. Griffiths (2001). Cytokines, stress and depressive illness. In: L.A. J. O’Neil and A. Bowie (Eds). Methods in Molecular Medicine, vol. 60. Humana Press Inc., Totoawa, NJ, pp. 217-238.

Anisman H, Hayley S & Merali Z (2001). Behavioral and central neurochemical consequences of cytokine challenge. In: J. Bienenstock, R. Gorzynski and I. Berczi (Eds). Neuroimmune Biology: New Foundation of Biology. Elsevier Science, pp. 141-162.

Anisman H, Hayley S, Staines WA & Merali Z (2001). Cytokines, Stress, and Neurochemical Change: Immediate and Proactive Effects. In: C. Shaw and J. McEachern (Eds). Neuroplasticity. Psychology Press, Philadelphia, PA, pp. 301-320.

Abstracts and/or Papers Read

Hayley S, Crocker S, Smith P, Shree T, Slack R & Park D (2003). Neuroprotective effects of Fas receptor deletion in the MPTP model of Parkinson’s disease. Society for Neuroscience, in press.

Crocker SJ, Smith P, Slack R, Robertson G, Lee R, Hayley S, Anisman H & Park DS (2002). Neuroprotective effects of intra-nigral infusion of calpastatin on MPTP-induced dopamine neuron loss and behavioural impairment in mice. Society for Neuroscience, Abst. # 487.7.

Kelly OP, Hayley SP, Merali Z, Anisman H & McIntyre DC (2002). Anxiety, acoustic startle and fear potentiated startle in rats selectively bred for fast and slow kindling rates. Society for neuroscience, Abst. # 571.12.

Hayley S, Kelly OP & Anisman H (2002). Profile of the sensitization effects of TNF- . Society for Neuroscience, Abst.# 868.5.

Sudom K, Hayley S, Kelly OP & Anisman H (2002). Early life endotoxin exposure influences behavioral and neurochemical responsivity to endotoxin or stressor challenges later in adulthood. Society for Neuroscience, Abst.# 773.2.

Hayley S, Merali Z & Anisman H (2001). Mice lacking the p55 TNF- receptor fail to show plasma corticosterone or sickness sensitization effects in response to systemic TNF- administration. Society for Neuroscience, 27.

Sudom, K. A., Hayley, S. P., Kelly, O. P., Merali, Z. & Anisman, H. (2001). Influence of chronic cytokine treatments: Neuroendocrine and anhedonic-like effects. Society for Neurosciences Abstracts, Abst. #634.26.

Kelly OP, Hayley S, Kokkinidis L & Anisman H (2001). Histaminergic modulation of the behavioral and neuorchemical sensitization effects elicited by tumour necrosis factor- . Society for Neuroscience, 27.

Hayley S, Ethier K, Wall P, Merali Z & Anisman H (2001). Sensitization effects of murine tumor necrosis factor- : Peripheral and central mechanisms. Brain Behavior and Immunity, in press.

Hayley S, Merali M, Staines W & Anisman H (2000) Immunohistochemical evidence for a time-dependent sensitization of neuroendocrine regulatory peptides in response to tumor necrosis factor-alpha. Brain Behavior and Immunity, 14 (2), 100.

Kelly OP, Hayley S, Merali Z, & Anisman H (2000). Psychogenic, neurogenic and systemic stressor effects: mouse strain-dependent outcomes on plasma corticosterone and anxiety. Society for neuroscience, 26, 998.

Hayley S, Dodd C, Merali Z, Anisman H (2000). Lipopolysaccharide pretreatment influences behavioral and neuroendocrine responses to subsequent cytokine, endotoxin or stressor exposure: cross-sensitization effects. Society for neuroscience, 26, 1179.

Ethier K, Hayley S, Ravindran A, Merali Z, Anisman H (2000). The acute and sensitizing actions of intracerebroventricular TNF- on behavioral and neuroendocrine processes. Society for neuroscience, 26, 1179.

Michaud D, Mclean J, Keith SE, Hayley S, Anisman H, Merali Z (2000). Audiogenic stressor alters corticosterone and brain CRH: differential effects in the lewis and fischer 344 rats. Society for neuroscience, 26, 2266.

Hayley S, Staines W, Merali Z & Anisman H (1999). Changes in immunoreactivity for AVP, CRH, NOS and GFAP in the murine brain after Tumor Necrosis Factor- treatment. Society for Neuroscience, 25, 1121.

Borowski TB, McIntyre DC, Hayley S, Merali Z & Anisman H (1999). Neurochemical variations and anxiety in seizure-resistant and seizure-prone rat strains. Society for Neuroscience, 25, 871.

Hayley S, Merali Z & Anisman H (1999). Immediate and protracted central neurochemical effects of tumor necrosis factor- . 6th Annual National Conference & Exhibition of the Ottawa Life Sciences Council, 3rd place winner in referee judged poster competition.

Hayley S, Brebner K, Staines W, Merali Z & Anisman H (1999). Time-dependent sensitization effects associated with tumor necrosis factor- ; behavioral and neurochemical processes. Neuroimmunomodulation, 6 (3), 224.

Hayley S, Brebner K, Merali Z & Anisman H. (1998). Sensitization and synergistic behavioral and neurochemical variations elicited by TNF- . Annual meeting for Brain Behavior and Cognitive Science (BBCS) ’98, Carleton University, Canada.

Hayley S, Brebner K, Staines W A, Merali Z & Anisman H. (1998). Sensitization effects of Tumor Necrosis Factor- : Behavioral, neuroendocrine and neurochemical alterations. Society for Neuroscience, 24, 1861.

Hayley S, Brebner K, Merali Z & Anisman H (1998). Sensitization to the Effects of TNF-alpha: Behavioral and Neurochemical Processes. On-line Proceedings of the 5th Internet World Congress on Biomedical Sciences ’98 at McMaster University, Canada.

Brebner K, Hayley S, Merali Z & Anisman H. (1998). Synergistic actions of interleukin-1 , IL-6 and TNF- : Central neurochemical, neuroendocrine and behavioral alterations. Society for Neuroscience, 24, 2075.

Borowski TB, Fairless S, Hayley S, Kokkinidis L, Merali Z & Anisman H. (1998). Strain-dependent variations of immune and neuroendocrine functioning in response to stressors. Society for Neuroscience, 24, 1863.

Hayley S, Lu Z W, Kent P, Merali Z & Anisman H. (1997). Endocrine and immune differences in strains of mice differentially reactive to stressors. Society for Neuroscience, 23, 713.

Hayley S & Harley CW (1996). Auditory sensory gating in the rat CA3 region of the hippocampus: Implications for an animal model of schizophrenia. 20th Annual Atlantic Provinces Council on the Sciences (APICS) Psychology conference, Mount Saint Vincent University, Haliax, Nova Scotia, Canada.