Infection results in the rapid onset of adaptive sickness responses, termed the acute phase response, and includes physiological changes such as fever, increased sleep, as well as behavioral changes such as reduced food and water intake, activity, exploration, and social interactions. These so-called """"""""sickness behaviors"""""""" are organized, adaptive strategies that are often crucial for host survival, rather than nonspecific manifestations of illness. Mounting an immune response is energetically costly. For many animals living in non-tropical habitats, a predictable annual energy shortage occurs each winter. During the short days of winter, low food availability often coincides with high thermoregulatory demands in low temperatures. Specific adaptations to conserve energy, such as inhibiting reproduction and growth, have evolved among animals to enhance winter survival. Immune function and responses to infection are also constrained by available energy, and may be altered by changes in the external environment. The proposed experiments are designed to investigate whether sickness behaviors or immune cell trafficking may be influenced by available energy or other factors signaled by melatonin.
The specific aims of the proposed research are: (1) To determine if early immune activation evokes long-term reproductive costs. (2) To determine if short-day alterations in sickness responses are mediated by melatonin. (3) To discover if melatonin acts directly on lymphocytes to alter cytokine production. (4) To determine if short days and melatonin reduce the duration of fever by affecting brain levels of cyclooxygenase (COX) and interleukin(IL)-1a. (5) To determine if photoperiod and melatonin affect immune cell populations and leukocyte trafficking. (6) To determine if photoperiod influences the extent to which stress compromises immune function. Taken together, these studies may reveal novel therapeutic uses of melatonin on fever and anorexia.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Project (R01)
Project #
5R01MH066144-02
Application #
6790677
Study Section
Special Emphasis Panel (ZRG1-IFCN-3 (01))
Program Officer
Winsky, Lois M
Project Start
2003-08-15
Project End
2007-06-30
Budget Start
2004-08-01
Budget End
2005-06-30
Support Year
2
Fiscal Year
2004
Total Cost
$290,752
Indirect Cost
Name
Ohio State University
Department
Neurosciences
Type
Schools of Medicine
DUNS #
832127323
City
Columbus
State
OH
Country
United States
Zip Code
43210
Martin, Lynn B; Weil, Zachary M; Nelson, Randy J (2008) Seasonal changes in vertebrate immune activity: mediation by physiological trade-offs. Philos Trans R Soc Lond B Biol Sci 363:321-39
Martin, Lynn B; Johnson, Eric M; Hutch, Chelsea R et al. (2008) 6-MBOA affects testis size, but not delayed-type hypersensitivity, in white-footed mice (Peromyscus leucopus). Comp Biochem Physiol A Mol Integr Physiol 149:181-7
Martin 2nd, Lynn B; Navara, Kristen J; Bailey, Michael T et al. (2008) Food restriction compromises immune memory in deer mice (Peromyscus maniculatus) by reducing spleen-derived antibody-producing B cell numbers. Physiol Biochem Zool 81:366-72
Bowers, Stephanie L; Bilbo, Staci D; Dhabhar, Firdaus S et al. (2008) Stressor-specific alterations in corticosterone and immune responses in mice. Brain Behav Immun 22:105-13
Weil, Zachary M; Workman, Joanna L; Nelson, Randy J (2007) Housing condition alters immunological and reproductive responses to day length in Siberian hamsters (Phodopus sungorus). Horm Behav 52:261-6
Weil, Zachary M; Bowers, Stephanie L; Nelson, Randy J (2007) Photoperiod alters affective responses in collared lemmings. Behav Brain Res 179:305-9
Martin, Lynn B; Trainor, Brian C; Finy, M Sima et al. (2007) HPA activity and neotic and anxiety-like behavior vary among Peromyscus species. Gen Comp Endocrinol 151:342-50
Martin 2nd, Lynn B; Weil, Zachary M; Nelson, Randy J (2007) Immune defense and reproductive pace of life in Peromyscus mice. Ecology 88:2516-28
Navara, Kristen J; Trainor, Brian C; Nelson, Randy J (2007) Photoperiod alters macrophage responsiveness, but not expression of Toll-like receptors in Siberian hamsters. Comp Biochem Physiol A Mol Integr Physiol 148:354-9
Navara, Kristen J; Nelson, Randy J (2007) The dark side of light at night: physiological, epidemiological, and ecological consequences. J Pineal Res 43:215-24

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