Norepinephrine Controls Both Torpor Initiation and Emergence via Distinct Mechanisms in the Mouse

Some mammals, including laboratory mice, enter torpor in response to food deprivation, and leptin can attenuate these bouts of torpor. We previously showed that dopamine β-hydroxylase knockout (Dbh −/−) mice, which lack norepinephrine (NE), do not reduce circulating leptin upon fasting nor do they enter torpor. To test whether the onset of torpor in mice during a fast requires a NE-mediated reduction in circulating leptin, double mutant mice deficient in both leptin (ob/ob) and DBH (DBL MUT) were generated. Upon fasting, control and ob/ob mice entered torpor as assessed by telemetric core Tb acquisition. While fasting failed to induce torpor in Dbh −/− mice, leptin deficiency bypassed the requirement for NE, as DBL MUT mice readily entered torpor upon fasting. These data indicate that sympathetic activation of white fat and suppression of leptin is required for the onset of torpor in the mouse. Emergence from torpor was severely retarded in DBL MUT mice, revealing a novel, leptin-independent role for NE in torpor recovery. This phenotype was mimicked by administration of a β3 adrenergic receptor antagonist to control mice during a torpor bout. Hence, NE signaling via β3 adrenergic receptors presumably in brown fat is the first neurotransmitter-receptor system identified that is required for normal recovery from torpor

Effects of Aging and Endurance Exercise Training on Adipose Tissue Gene Expression in Rats

Aging in both humans and rodent models is typically associated with an increase in fat mass while endurance exercise reduces total fat mass. We hypothesize that aging in Fischer-344 rats will cause adaptations in adipose tissue that promote increased fat storage, while endurance exercise training will cause adipose tissue to resist fat deposition. Earlier work identified 19 genes whose expression in adipose tissue appeared to be affected by exercise training in aged rats. This work focuses on one of those genes, DNA binding inhibitor-1 (ID1), which has been shown by others to regulate adipocyte proliferation and differentiation. The goal of this work is to use real-time polymerase chain reaction to verify that exercise training reduces the expression of this gene in aged rats. In addition, we are also determining if expression of this gene is affected by aging, and if the effect of exercise training on ID1 gene expression is different between 15 month old, and 27 month old rats

The relevance of emotional intelligence in personnel selection for high emotional labor jobs

Although a large number of studies have pointed to the potential of emotional intelligence (EI) in the context of personnel selection, research in real-life selection contexts is still scarce. The aim of the present study was to examine whether EI would predict Assessment Center (AC) ratings of job-relevant competencies in a sample of applicants for the position of a flight attendant. Applicants’ ability to regulate emotions predicted performance in group exercises. However, there were inconsistent effects of applicants’ ability to understand emotions: Whereas the ability to understand emotions had a positive effect on performance in interview and role play, the effect on performance in group exercises was negative. We suppose that the effect depends on task type and conclude that tests of emotional abilities should be used judiciously in personnel selection procedures