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#47 Varying social structures does not influence the effects of pair housing on wound healing
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Abstracts / Brain, Behavior, and Immunity 19 (2005) e1–e42
Acknowledgments Supported by NIH HL-65346 and HL-69755. doi:10.1016/j.bbi.2005.10.051
either be a result of an increase of innate immune response to LPS (e.g., the same dose of LPS provokes higher levels of circulating cytokines) with a stronger concomitant central response, or the brain is somehow sensitized to inflammatory mediators in general. Acknowledgments
#46 Aging exacerbates the brain response to pro-inflammatory challenge in mice Ronald P.A. Gaykema a, Madhu K. Balachandran a, Jonathan P. Godbout b, Rodney W. Johnson b, Lisa E. Goehler a
This study was supported by NIH Grants AG16710 and MH069148 to R.W.J., MH64848 and MH66834 to L.E.G. doi:10.1016/j.bbi.2005.10.052
a
Laboratory for Neuroimmunology and Behavior, Department of Psychology, University of Virginia, Charlottesville, VA 22904, USA b Division of Nutritional Sciences and Department of Animal Sciences, University of Illinois, 1207 W. Gregory Drive, Urbana, IL 61801, USA Little is known how aging affects brain-immune system interactions and neural responsiveness to inflammatory insults in particular. Aging related cognitive decline is often attributed to increased inflammatory mediators in the brain in part due to a ÔprimedÕ state of microglia and raised levels of interleukin-6. In the present study, we assessed whether aging leads to either blunted or exacerbated neural response in the mouse brain to peripheral pro-inflammatory challenge. Adult (3–6 m) and aged (22–24) Balb/c mice were housed in SPF conditions under reverse phase 12:12 h light:dark cycle. The mice were injected ip 1 h into the start of the dark cycle with sterile saline or Escherichia coli LPS (0.33 mg/kg; serotype 0127:B8, Sigma, St. Louis, MO). They were sacrificed 4 h later by CO2 asphyxiation, rapidly perfused with sterile saline, and fixed in 4% paraformaldehyde. Brain sections were processed for Fos immunohistochemistry and analyzed with the aid of a microscope, digital camera and NIH Image software. The aged mice showed an exacerbated response to LPS as compared to the young adult controls. The number of Fos-immunoreactive neurons were significantly higher in the aged mice in various brain regions including the nucleus of the solitary tract, locus coeruleus, and paraventricular nucleus of the hypothalamus. In the aged mice, Fos immunoreactivity was also highly abundant in the circumventricular organs, choroids plexus and the cells of the ventricular ependyma. Many of the Fos-positive cells appear to be non-neuronal in nature. In comparison, Fos expression in these structures was rather sparse in the young adult mice. Saline treated mice showed little or no Fos immunoreactivity irrespective of their age. These results indicate that aging leads to increase of the neural response to LPS-induced inflammation. In addition, non-neuronal cells in the brain appear to be recruited in much larger numbers in aged mice. These effects could
#47 Varying social structures does not influence the effects of pair housing on wound healing Erica Glasper, A. Courtney DeVries Departments of Psychology and Neuroscience, The Ohio State University, USA Chronic stress or noxious stimuli delay wound healing in humans and rodents. The effects of stress on wound healing appear to be mediated by the hypothalamic–pituitary–adrenal axis and, in particular, increases in corticosteroids. Depending on the circumstance, social interactions can be a source of stress or provide a buffer against stress. As previously shown, positive social interaction facilitates wound healing through suppression of corticosteroids, however, the benefits of social housing are not equivalent for all species and may be limited to those that are monogamous or highly social. In contrast, social stress can have deleterious effects on health. In the present study, we investigated the effects of the following variables on wound healing and corticosterone response: (1) pair housing versus social isolation, (2) sex of the experimental animal, (3) sex of the partner, and (4) exposure to stress. We compared outcome in two mouse species with different social structures, Peromyscus californicus (monogomous) and P. leucopus (polygynous). Overall, P. leucopus had lower corticosterone concentrations and healed more quickly than P. californicus. Regardless of the sex of the partner, pair-housed P. californicus healed more quickly than single housed cohorts. In contrast, no differences were observed between single housed and pair housed P. leucopus, regardless of pairing condition. Three hours of daily restraint prior to and following wounding did not alter healing rate in either P. californicus or P. leucopus. Taken together, these data suggest that social contact facilitates wound healing in a monogamous, but not polygynous, mouse species irrespective of the sex of the partner. doi:10.1016/j.bbi.2005.10.053
Abstracts / Brain, Behavior, and Immunity 19 (2005) e1–e42
Acknowledgments Supported by NIH HL-65346 and HL-69755. doi:10.1016/j.bbi.2005.10.051
either be a result of an increase of innate immune response to LPS (e.g., the same dose of LPS provokes higher levels of circulating cytokines) with a stronger concomitant central response, or the brain is somehow sensitized to inflammatory mediators in general. Acknowledgments
#46 Aging exacerbates the brain response to pro-inflammatory challenge in mice Ronald P.A. Gaykema a, Madhu K. Balachandran a, Jonathan P. Godbout b, Rodney W. Johnson b, Lisa E. Goehler a
This study was supported by NIH Grants AG16710 and MH069148 to R.W.J., MH64848 and MH66834 to L.E.G. doi:10.1016/j.bbi.2005.10.052
a
Laboratory for Neuroimmunology and Behavior, Department of Psychology, University of Virginia, Charlottesville, VA 22904, USA b Division of Nutritional Sciences and Department of Animal Sciences, University of Illinois, 1207 W. Gregory Drive, Urbana, IL 61801, USA Little is known how aging affects brain-immune system interactions and neural responsiveness to inflammatory insults in particular. Aging related cognitive decline is often attributed to increased inflammatory mediators in the brain in part due to a ÔprimedÕ state of microglia and raised levels of interleukin-6. In the present study, we assessed whether aging leads to either blunted or exacerbated neural response in the mouse brain to peripheral pro-inflammatory challenge. Adult (3–6 m) and aged (22–24) Balb/c mice were housed in SPF conditions under reverse phase 12:12 h light:dark cycle. The mice were injected ip 1 h into the start of the dark cycle with sterile saline or Escherichia coli LPS (0.33 mg/kg; serotype 0127:B8, Sigma, St. Louis, MO). They were sacrificed 4 h later by CO2 asphyxiation, rapidly perfused with sterile saline, and fixed in 4% paraformaldehyde. Brain sections were processed for Fos immunohistochemistry and analyzed with the aid of a microscope, digital camera and NIH Image software. The aged mice showed an exacerbated response to LPS as compared to the young adult controls. The number of Fos-immunoreactive neurons were significantly higher in the aged mice in various brain regions including the nucleus of the solitary tract, locus coeruleus, and paraventricular nucleus of the hypothalamus. In the aged mice, Fos immunoreactivity was also highly abundant in the circumventricular organs, choroids plexus and the cells of the ventricular ependyma. Many of the Fos-positive cells appear to be non-neuronal in nature. In comparison, Fos expression in these structures was rather sparse in the young adult mice. Saline treated mice showed little or no Fos immunoreactivity irrespective of their age. These results indicate that aging leads to increase of the neural response to LPS-induced inflammation. In addition, non-neuronal cells in the brain appear to be recruited in much larger numbers in aged mice. These effects could
#47 Varying social structures does not influence the effects of pair housing on wound healing Erica Glasper, A. Courtney DeVries Departments of Psychology and Neuroscience, The Ohio State University, USA Chronic stress or noxious stimuli delay wound healing in humans and rodents. The effects of stress on wound healing appear to be mediated by the hypothalamic–pituitary–adrenal axis and, in particular, increases in corticosteroids. Depending on the circumstance, social interactions can be a source of stress or provide a buffer against stress. As previously shown, positive social interaction facilitates wound healing through suppression of corticosteroids, however, the benefits of social housing are not equivalent for all species and may be limited to those that are monogamous or highly social. In contrast, social stress can have deleterious effects on health. In the present study, we investigated the effects of the following variables on wound healing and corticosterone response: (1) pair housing versus social isolation, (2) sex of the experimental animal, (3) sex of the partner, and (4) exposure to stress. We compared outcome in two mouse species with different social structures, Peromyscus californicus (monogomous) and P. leucopus (polygynous). Overall, P. leucopus had lower corticosterone concentrations and healed more quickly than P. californicus. Regardless of the sex of the partner, pair-housed P. californicus healed more quickly than single housed cohorts. In contrast, no differences were observed between single housed and pair housed P. leucopus, regardless of pairing condition. Three hours of daily restraint prior to and following wounding did not alter healing rate in either P. californicus or P. leucopus. Taken together, these data suggest that social contact facilitates wound healing in a monogamous, but not polygynous, mouse species irrespective of the sex of the partner. doi:10.1016/j.bbi.2005.10.053