Prior experience with behavioral control over stress facilitates social dominance.

Dominance status has extensive effects on physical and mental health, and an individual's relative position can be shaped by experiential factors. A variety of considerations suggest that the experience of behavioral control over stressors should produce winning in dominance tests and that winning should blunt the impact of later stressors, as does prior control. To investigate the interplay between competitive success and stressor control, we first examined the impact of stressor controllability on subsequent performance in a warm spot competition test modified for rats. Prior experience of controllable, but not physically identical uncontrollable, stress increased later effortful behavior and occupation of the warm spot. Controllable stress subjects consistently ranked higher than did uncontrollable stress subjects. Pharmacological inactivation of the prelimbic (PL) cortex during behavioral control prevented later facilitation of dominance. Next, we explored whether repeated winning experiences produced later resistance against the typical sequelae of uncontrollable stress. To establish dominance status, triads of rats were given five sessions of warm spot competition. The development of stable dominance was prevented by reversible inactivation of the PL or NMDA receptor blockade in the dorsomedial striatum. Stable winning blunted the later stress-induced increase in dorsal raphe nucleus serotonergic activity, as well as prevented uncontrollable stress-induced social avoidance. In contrast, endocrine and neuroimmune responses to uncontrollable stress were unaffected, indicating a selective impact of prior dominance. Together, these data demonstrate that instrumental control over stress promotes later dominance, but also reveal that winning experiences buffer against the neural and behavioral outcomes of future adversity.

Prior experience with behavioral control over stress facilitates social dominance.

Dominance status has extensive effects on physical and mental health, and an individual's relative position can be shaped by experiential factors. A variety of considerations suggest that the experience of behavioral control over stressors should produce winning in dominance tests and that winning should blunt the impact of later stressors, as does prior control. To investigate the interplay between competitive success and stressor control, we first examined the impact of stressor controllability on subsequent performance in a warm spot competition test modified for rats. Prior experience of controllable, but not physically identical uncontrollable, stress increased later effortful behavior and occupation of the warm spot. Controllable stress subjects consistently ranked higher than did uncontrollable stress subjects. Pharmacological inactivation of the prelimbic (PL) cortex during behavioral control prevented later facilitation of dominance. Next, we explored whether repeated winning experiences produced later resistance against the typical sequelae of uncontrollable stress. To establish dominance status, triads of rats were given five sessions of warm spot competition. Reversible inactivation of the PL or NMDA receptor blockade in the dorsomedial striatum led to a long-term reduction in social rank. Stable dominance blunted the later stress-induced increase in dorsal raphe nucleus serotonergic activity, as well as prevented stress-induced social avoidance. In contrast, endocrine and neuroimmune responses to uncontrollable stress were unaffected, indicating a selective impact of prior dominance. Together, these data demonstrate that instrumental control over stress promotes later dominance, but also reveal that winning experiences buffer against the neural and behavioral outcomes of future adversity.

A low-glycemic nutritional fitness program to reverse metabolic syndrome in professional firefighters: results of a pilot study.

BACKGROUND: The risk for cardiovascular events is higher for those with metabolic syndrome (MetS), and it is known that firefighters have a 4-fold risk for cardiovascular events. The purpose of this study was to quantify MetS prevalence and evaluate the effect of a low-glycemic nutritional fitness program on the reduction of MetS risk factors among firefighters. METHODS: Professional firefighters were screened for MetS then enrolled in a low-glycemic nutritional fitness program for a 12-week period. Anthropometric and physiological measurements were obtained at the start and end of the program. Subjects with 3 or more of the following were positive for MetS: waist-40-inches or greater (men) or 35 inches or greater (women), blood pressure 135 mm Hg or greater (systole) or 85 mm Hg or greater (diastole), fasting blood sugar 100 mg/dL or greater, triglycerides 150 mg/dL or greater, and high-density lipoproteins less than 40 mg/dL (men) or less than 50 mg/dL (women). Weekly sessions provided low-glycemic nutrition instruction, fitness training, and evaluation of individual progress. RESULTS: Seventy-five firefighters (aged 42 [SD, 8] years, mostly white men) had a total MetS prevalence of 46.7% (P<.05 vs normal population). One platoon (10 men, aged 48 [SD, 5] years) was enrolled in the 12-week program. Most (7/10) had MetS at the baseline, but this prevalence decreased significantly after 12 weeks to 3 subjects (P=.02). On average, subjects had 3.2 (SD, 1.6) versus 1.9 (SD, 1.7) MetS risk factors (P<.01) at baseline and the 12-week interval, respectively. CONCLUSIONS: The prevalence of MetS and MetS risk factors is higher among professional firefighters compared with the general population. A short-duration, low-glycemic fitness program can successfully improve anthropometric and physiological measures and reduce the prevalence of MetS.