Physiology & behavior
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Physiology & behavior · May 2012
Low-carbohydrate high-fat diets in combination with daily exercise in rats: effects on body weight regulation, body composition and exercise capacity.
The aim of the current investigation was to examine the effects of consuming a low-carbohydrate high-fat diet (LC-HFD) in combination with daily exercise on body weight, body composition, endocrine control of the energy balance system and exercise capacity in adolescent and mature rats. ⋯ Maintenance on the LC-HFD in combination with forced daily exercise did not impact exercise capacity (total distance and meters per minute). Additionally consumption of an extreme LC-HFD in combination with daily exercise resulted in significantly less body weight gain but increased fat mass. When combined with daily exercise this diet clearly had a negative impact on body composition, but did not affect exercise capacity.
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Physiology & behavior · Apr 2012
ReviewMediators of allostasis and systemic toxicity in bipolar disorder.
Bipolar disorder is associated with a high rate of medical and psychiatric comorbidities. This burden of illness, along with cognitive impairment, is seen particularly in late cases, after multiple episodes. These changes in clinical presentation that take place over time have been recently conceptualized as "neuroprogression". ⋯ Allostatic load is engendered by several factors which interact in a nonlinear manner. Glucocorticoids are fundamental mediators; when chronically in excess, glucocorticoids initiate a series of bodily dysfunctions that may include cortisol-related mitochondrial dysfunction, oxidative stress, inflammation and decrease in the expression of neuroprotective factors. In the present review we examine the role of allostatic load in the illness progression that takes place in bipolar disorder.
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Physiology & behavior · Apr 2012
The salivary alpha amylase over cortisol ratio as a marker to assess dysregulations of the stress systems.
Different factors have been associated with changes in the regulation of the two major stress response systems of the human body, the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis. Changes in these systems have been associated with various (psycho)pathologies across adulthood, and are thus frequently assessed within the context of allostatic load. Early Life Adversity (ELA) has been identified as one such factor. ⋯ Using a specific formula to determine the ratio of sAA over cortisol, we found a systematically stronger positive relationship with indexes of chronic stress and depression when compared to cortisol over sAA, or either marker alone. Our findings suggest that the ratio of sAA over cortisol might be a better marker of stress systems dysregulation than the ratio of cortisol over sAA, sAA or cortisol alone. The usefulness of this marker for other chronic stress states as found in allostatic load is discussed.
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Physiology & behavior · Mar 2012
Genetic differences in temperament determine whether lavender oil alleviates or exacerbates anxiety in sheep.
Growing concerns about the risk of addiction to benzodiazepines have led to increasing interest in alternative therapies to treat anxiety and depression. Lavender oil (Lavendula augustifolia) is reportedly anxiolytic in a number of species but little is known about how it affects individuals that are more or less anxious when faced with a stressor. In this study, we used changes in locomotor activity and the plasma concentrations of cortisol to test whether lavender oil would reduce behavioral and endocrine correlates of anxiety in calm and nervous sheep exposed to an isolation stressor. ⋯ Exposure of calm sheep to lavender oil decreased the agitation score (P<0.001), frequency of vocalizations (P<0.05), decreased the number of crosses of the central lines of the isolation box (P<0.05), and the plasma concentrations of cortisol prior to isolation (P<0.05) (after mask application) compared to calm control sheep. Exposure of nervous sheep to lavender oil increased the frequency of vocalizations (P<0.05), the number of sheep attempting to escape (P<0.05) and the plasma concentrations of cortisol 30 min after isolation (P<0.05) compared to nervous control sheep. We conclude that genetic differences in temperament determine whether lavender oil alleviates or exacerbates the behavioral and/or endocrine correlates of anxiety in sheep.
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Physiology & behavior · Feb 2012
Availability of a rich source of sodium during the perinatal period programs the fluid balance restoration pattern in adult offspring.
Osmoregulatory mechanisms can be vulnerable to electrolyte and/or endocrine environmental changes during the perinatal period, differentially programming the developing offspring and affecting them even in adulthood. The aim of this study was to evaluate whether availability of hypertonic sodium solution during the perinatal period may induce a differential programming in adult offspring osmoregulatory mechanisms. With this aim, we studied water and sodium intake after Furosemide-sodium depletion in adult offspring exposed to hypertonic sodium solution from 1 week before mating until postnatal day 28 of the offspring, used as a perinatal manipulation model [PM-Na group]. ⋯ Moreover, along the brainstem, we found a decreased number of sodium depletion-activated cells within the nucleus of the solitary tract of the PM-Na group. Our data indicate that early sodium availability induces a long-term effect on fluid drinking and on the cell activity of brain nuclei involved in the control of hydromineral balance. These results also suggest that availability of a rich source of sodium during the perinatal period may provoke a larger anticipatory response in the offspring, activating the vasopressinergic system and reducing thirst after water and sodium depletion, as a result of central osmosensitive mechanism alterations.