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Seasonally breeding animals respond to environmental cues to determine optimal conditions for reproduction. Siberian hamsters (Phodopus sungorus) primarily rely on photoperiod as a predictive cue of future energy availability. When raised in long-day photoperiods (>14 h light), supplemental cues such as food availability typically do not trigger the seasonal reproductive response of gonadal regression, which curtails reproduction in unsuitable environments. We investigated whether recognition of food availability as a cue could be altered by a nutritional challenge during development. Specifically, we predicted that hamsters receiving restricted food during development would be sensitized to food restriction (FR) as adults and undergo gonadal regression in response. Male and female hamsters were given either ad libitum (AL) food or FR from weaning until d60. The FR treatment predictably limited growth and delayed puberty in both sexes. For 5 weeks after d60, all hamsters received an AL diet to allow FR hamsters to gain mass equal to AL hamsters. Then, adult hamsters of both juvenile groups received either AL or FR for 6 weeks. Juvenile FR had lasting impacts on adult male body mass and food intake. Adult FR females exhibited decreased estrous cycling and uterine horn mass indiscriminately of juvenile food treatment, but there was little effect on male reproductive measurements. Overall, we observed a delay in puberty in response to postweaning FR, but this delay appeared not to affect seasonal reproductive responses in the long term. These findings increase our understanding of seasonal reproductive responses in a relevant environmental context.

Objective To evaluate a proactive, voluntary screening program designed to identify employees with emerging mental health risk and engage them in care. Methods Risk was proactively identified through online screening of 344 participants. At-risk participants were offered a mental health care concierge to provide support, develop a care plan, and connect to care. Results Risk for common mental health conditions was identified in 244 (71%) participants, of whom 66 (27%) connected with a care concierge. Compared with participants who did not connect to a care concierge, those who did were more likely to report a financial crisis (68.2% vs 50.8%) and less likely to report verbal abuse (9.1% vs 19.6%) and difficulty meeting daily needs (12.1% vs 25.1%). Conclusion Implementation of this screening program identified employees at risk for mental health conditions and facilitated connection to care.

Activation of the immune system induces rapid reductions in hypothalamic-pituitary-gonadal (HPG) axis activity, which in turn decreases secretion of sex steroids. This response is likely adaptive for survival by temporarily inhibiting reproduction to conserve energy; however, the physiological mechanisms controlling this response remain unclear. The neuropeptide kisspeptin is a candidate to mediate the decrease in sex hormones seen during sickness through its key regulation of the HPG axis. In this study, the effects of acute immune activation on the response to kisspeptin were assessed in male Siberian hamsters (Phodopus sungorus). Specifically, an immune response was induced in animals by a single treatment of lipopolysaccharide (LPS), and reproductive hormone concentrations were determined in response to subsequent injections of exogenous kisspeptin. Saline-treated controls showed a robust increase in circulating testosterone in response to kisspeptin; however, this response was blocked in LPS-treated animals. Circulating luteinizing hormone (LH) levels were elevated in response to kisspeptin in both LPS- and saline-treated groups and, thus, were unaffected by LPS treatment, suggesting gonad-level inhibition of testosterone release despite central HPG activation. In addition, blockade of glucocorticoid receptors by mifepristone did not attenuate the LPS-induced inhibition of testosterone release, suggesting that circulating glucocorticoids do not mediate this phenomenon. Collectively, these findings reveal that acute endotoxin exposure rapidly renders the gonads less sensitive to HPG stimulation, thus effectively inhibiting sex hormone release. More broadly, these results shed light on the effects of immune activation on the HPG axis and help elucidate the mechanisms controlling energy allocation and reproduction.

Animals living in temperate climates respond to environmental cues that signal current and future resource availability to ensure that energy resources are available to support reproduction. Siberian hamsters (Phodopus sungorus) undergo robust gonadal regression in short, winter-like photoperiods as well as in response to mild food restriction in intermediate photoperiods. The goal of the present study was to investigate whether leptin is a relevant metabolic signal in regulating gonadal regression in response to diminishing food availability. Adult female hamsters housed in short-day (winter-like) or intermediate (fall-like) photoperiods received either ad libitum access to food or mild food restriction (90% of ad libitum intake) and were treated with either leptin or a vehicle for five weeks in order to determine the ability of leptin to inhibit gonadal regression. At the end of five weeks, vehicle-treated hamsters showed physiological signs associated with ongoing gonadal regression, such as decreases in body mass and food intake, cessation of estrous cycling, and small decreases in reproductive tissue mass. Leptin did not modify changes in body mass, food intake, hormone concentration, or tissue mass, but showed a tendency to support estrous cycling, particularly in response to food restriction in the intermediate photoperiod treatment. Overall, leptin appears to play a minor role in coordinating reproductive responses to multiple environmental cues, at least in the early stages of gonadal regression.

Animals living in temperate regions prepare for harsh winter conditions by responding to environmental cues that signal resource availability (e.g., food, day length). Siberian hamsters (Phodopus sungorus) breed in long, summer-like days (LD, > 14 h light), i.e., photoperiods, and undergo robust gonadal regression and become more aggressive when exposed to short, winter-like photoperiods that signal impending limited resources (SD