Analytic and Interpretational Pitfalls to Measuring Fecal Corticosterone Metabolites in Laboratory Rats and Mice.

Minimization and alleviation of stress are generally viewed as desirable aspects of laboratory animal management and use. However, achieving that goal requires an unambiguous and valid measure of stress. Glucocorticoid concentrations are commonly used as a physiologic index of stress.

Interacting Influences of Sleep, Pain, and Analgesic Medications on Sleep Studies in Rodents.

This overview provides a brief summary of the complex interactions that link sleep, pain, and analgesic medications. Sleep scientists and clinicians are well aware of these relationships and understand that maintaining healthy pain-free subjects in a stable environment is essential to generating interpretable data and valid conclusions. However, these concepts and the data that support bidirectional interactions between sleep and pain may be less known to those who are not sleep scientists yet need such information to protect and advance both animal wellbeing and research validity (for example, veterinarians, IACUC members).

Impaired Recovery from Influenza A/X-31(H3N2) Infection in Mice with 8-Lipoxygenase Deficiency.

Lipoxygenase-derived lipid mediators can modulate inflammation and are stimulated in response to influenza infections. We report an effect of 8-lipoxygenase (ALOX8) on the recovery of mice after infection with Influenza virus X31. We compared the responses of 3- and 6-month-old mice with a deletion of ALOX8 (ALOX8) to influenza infections with those of age-matched littermate wild-type mice (ALOX8).

Identifying and Implementing Endpoints for Geriatric Mice.

The types of changes in physical appearance and behavior that occur in elderly people similarly develop in elderly animals. Signs and symptoms that might cause concern in younger people or mice may be normal in their elderly but generally healthy counterparts. Although numerous scoring methods have been developed to assess rodent health, these systems were often designed for young adults used in specific types of research, such as cancer or neurologic studies, and therefore may be suboptimal for assessing aging rodents.

Influence of Chronic Exposure to Simulated Shift Work on Disease and Longevity in Disease-Prone Inbred Mice.

Shift work (SW) is viewed as a risk factor for the development of many serious health conditions, yet prospective studies that document such risks are rare. The current study addressed this void by testing the hypothesis that long-term exposure to repeated diurnal phase shifts, mimicking SW, will accelerate disease onset or death in inbred mice with genetic risk of developing cancer, diabetes, or autoimmune disease. The data indicate that 1) life-long exposure to simulated SW accelerates death in female cancerprone AKR/J mice; 2) a significant proportion of male NON/ShiLtJ mice, which have impaired glucose tolerance but do not normally progress to type 2 diabetes, develop hyperglycemia, consistent with diabetes (that is, blood glucose 250 mg/dL or greater) after exposure to simulated SW for 8 wk; and 3) MRL/MpJ mice, which are prone to develop autoimmune disease, showed sex-related acceleration of disease development when exposed to SW as compared with mice maintained on a stable photocycle.

Effects of Chronic Diurnal Disruption and Acute Inflammatory Challenge on Mice with Latent Murine Gammaherpesvirus Infection.

People who engage in shift work (SW) have increased risk of developing illnesses, including infectious diseases and various inflammatory conditions. We hypothesized that exposure to repeated cycles of diurnal disruption, mimicking SW, influences viral clearance, latent viral load, or viral reactivation from latency in mice infected with murine gammaherpesvirus (MuGHV). To test this idea, we inoculated BALB/cByJ and C.

Interactions Between Housing Density and Ambient Temperature in the Cage Environment: Effects on Mouse Physiology and Behavior.

To determine how housing density and ambient temperature interact to influence the physiology and behavior of mice, we systematically varied housing density (1 to 5 mice per cage) and ambient temperature (22, 26, or 30 °C) and measured effects on body weight, food intake, diurnal patterns of locomotor activity and core temperature, fecal corticosterone, and serum cytokine and adipokine panels. Temperatures inside cages housing 5 mice were 1 to 2 °C higher than the ambient temperature. As the housing density decreased, in-cage temperatures began to fall at a density of 2 or 3 mice per cage and did not differ from ambient temperature at 1 mouse per cage.

Effects of Sleep Fragmentation and Chronic Latent Viral Infection on Behavior and Inflammation in Mice.

Many chronic diseases are associated with both fatigue and disrupted or nonrestorative sleep. In addition, so-called 'sickness behaviors' (for example, anorexia, anhedonia, reduced social interaction, fatigue) are common during infectious and inflammatory disease and have been linked to facets of the immune response. To study these relationships, we used murine gammaherpesvirus (MuGHV), a natural pathogen of wild rodents that provides an experimental model for studying the pathophysiology of an Epstein-Barr (EBV)-like γ-herpesvirus infection in mice.