Sleep in female mice: a strain comparison across the estrous cycle

STUDY OBJECTIVE

Studying inbred strains of mice has proven useful in uncovering genetic variation in the expression of sleep patterns. However, although genetic influence on many behaviors has been shown to be gender specific, to date, sleep patterns in different strains of female mice have not been reported. In order to perform such studies in female mice, the estrous cycle must be taken into account in view of the effects of reproductive hormones on sleep. The aim of this study was thus to determine sleep patterns in female mice of different inbred strains over the estrous cycle.

DESIGN

Three strains of mice were used. Vaginal smears were performed to determine the estrous cycle stage; electroencephalographic and electromyographic activity, as well as body temperature and locomotor activity collected during a full estrous cycle, were analyzed.

MEASUREMENTS AND RESULTS

We report a major impact of the genetic background in the regulation of non-rapid eye movement sleep over a 24-hour period and clear strain differences in rapid eye movement sleep distribution over the light-dark cycle. In contrast, the estrous cycle had less influence on non-rapid eye movement sleep and rapid eye movement sleep, and these effects were dependent on the genotype of the mice.

CONCLUSIONS

Sleep regulation in female mice is influenced primarily by genetic background and, to a lesser extent, by hormonal variations associated with the estrous cycle.

Acquired immunodeficiency syndrome-related blastomycosis in an unusual geographic location

Blastomycosis is a fungal infection acquired via inhalation of Blastomyces dermatitidis. The majority of cases occur in central, southeastern, and mid-Atlantic areas of the United States. We report the case of a 42-year-old veteran infected with the human immunodeficiency virus who presented in E1 Paso, Texas, with a dry cough, fever, and recent weight loss. We review the clinical and epidemiologic features of blastomycosis. Diagnostic criteria and pharmacologic management are discussed. Active duty personnel are at high risk of exposure to B. dermatitidis. Military providers should maintain an index of suspicion for blastomycosis in endemic and nonendemic regions.