Physiology & behavior
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Physiology & behavior · Oct 2012
Acute psychosocial stress differentially influences salivary endocrine and immune measures in undergraduate students.
Undergraduate students routinely experience acute psychosocial stress when interviewing for post-collegiate employment. While numerous studies have demonstrated that acute stress can increase release of immune-relevant molecules in blood, fewer studies have examined if acute stress also increases immune-relevant molecules into saliva. Saliva, and the biomolecules found in saliva often serve important immune defense roles and can be used to non-invasively screen for many systemic diseases. ⋯ These results suggest that acute stress experienced by undergraduates when interviewing for a job activates the sympathetic nervous system and hypothalamic-pituitary-adrenal axis and that cortisol levels increase in saliva. Stress-induced elevations in cortisol might be responsible for the decreased S-IgA observed following the recovery period. Collectively, these data provide further insight into the interaction between psychosocial stress, endocrine, and immune functioning.
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Physiology & behavior · Oct 2012
Isolation rearing attenuates social interaction-induced expression of immediate early gene protein products in the medial prefrontal cortex of male and female rats.
Early life adversity and stress in humans have been related to a number of psychological disorders including anxiety, depression, and addiction. The present study used isolation rearing, a well-characterized animal model of early life adversity, to examine its effects on social behavior and immediate early gene (IEG) expression produced by exposure to a novel social experience. Male and female rats were housed in same-sex groups or in isolation for 4 weeks beginning at weaning and were tested during late adolescence. ⋯ Isolates engaged in more social interactions and more aggressive behavior than group reared rats. Sex differences in some behaviors as well as in Arc and BDNF expression were observed. These results indicate that isolation rearing alters IEG activation in the mPFC produced by exposure to a novel conspecific, in addition to changing social behavior, and that these effects depend in part on sex.
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Physiology & behavior · Oct 2012
Impact of maternal mild hyperglycemia on maternal care and offspring development and behavior of Wistar rats.
The aim of the present study was to evaluate the effect of maternal mild hyperglycemia on maternal behavior, as well as the development, behavior, reproductive function, and glucose tolerance of the offspring. At birth, litters were assigned either to Control (subcutaneous (sc)-citrate buffer) or STZ groups (streptozotocin (STZ)-100mg/kg-sc.). On PND 90 both STZ-treated and Control female rats were mated. ⋯ There was no impairment in the sexual behavior of either male or female offspring. As adults, female offspring of STZ-treated mothers did not show glucose intolerance during pregnancy. Thus, offspring of female rats that show mild hyperglycemia in pregnancy have fewer behavioral and developmental impairments than previously reported in the offspring of severely diabetic dams suggesting that the degree of impairment is directly related to the mother glycemic intensity.
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Physiology & behavior · Oct 2012
Why do some like it hot? Genetic and environmental contributions to the pleasantness of oral pungency.
Although potential environmental influences on hedonic responses to oral pungency have been identified, little is known of the possible role of genetics underlying these responses. We explored the contribution of genetic and environmental influences on the pleasantness of oral pungency and spicy foods. Respondents were young adult Finnish twins (n=331, 21-25 years), including 47 complete monozygotic and 93 dizygotic twin pairs and 51 twin individuals without their co-twin. ⋯ All pleasantness traits (sensory and questionnaire based) were shown to share a common genetic variance. This indicates that an underlying genetic aptitude to like oral pungency, and spicy foods exists and it is expressed in these measures. The findings broaden the understanding of the diverse nature of individual food preferences and motivate further search for the underlying genetic components of oral pungency.
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Physiology & behavior · Oct 2012
Metabolic consequences of chronic sleep restriction in rats: changes in body weight regulation and energy expenditure.
Epidemiological studies have shown an association between short or disrupted sleep and an increased risk to develop obesity. In animal studies, however, sleep restriction leads to an attenuation of weight gain that cannot be explained by changes in energy intake. In the present study, we assessed whether the attenuated weight gain under conditions of restricted sleep is a consequence of an overall increase in energy expenditure. ⋯ Baseline plasma glucose, insulin and leptin levels are decreased after sleep restriction which presumably reflects the nutritional status of the rats. The daily energy expenditure during SR was significantly increased compared to control rats. Together, we conclude that the attenuation of body weight gain in sleep restricted rats is explained by an overall increase in energy expenditure together with an unaltered energy intake.