Complex Adaptation (complex + adaptation)

Distribution by Scientific Domains


Selected Abstracts


Pinealectomy reduces hepatic and muscular glycogen content and attenuates aerobic power adaptability in trained rats

JOURNAL OF PINEAL RESEARCH, Issue 1 2007
Cristina das Neves Borges-Silva
Abstract:, The current study emphasizes the crucial role of the pineal gland on the effects of chronic training in different tissues focusing on carbohydrate metabolism. We investigated the maximal oxygen uptake (aerobic power), muscle and liver glycogen content, and also the enzymes involved in the carbohydrate metabolism of rat adipose tissue. Pinealectomized and sham-operated adult male Wistar rats were distributed into four groups: pinealectomized (PINX) untrained, pinealectomized trained, control untrained and control trained. The maximal oxygen uptake capability was assayed before and after the training protocol by indirect open circuit calorimetry. The rats were killed after 8 wk of training. Blood samples were collected for glucose and insulin determinations. The glycogen content was assayed in the liver and muscle. Maximal activities of epididymal adipose tissue enzymes (hexokinase, pyruvate kinase, lactate dehydrogenase, citrate synthase and malic enzyme) as well as adipocyte size were determined. The exercise training in control animals promoted an increase in the aerobic power and in liver glycogen content but caused a reduction in the malic enzyme activity in adipose tissue. However, PINX trained animals, in contrast to trained controls, showed a decrease in the aerobic power and in liver and muscle glycogen content, as well as an increase in the activity of the adipocyte enzymes involved in carbohydrate metabolism. In conclusion, these data show that the pineal gland integrity is necessary for the homeostatic control of energy metabolism among adipose, muscle and hepatic tissues. The pinealectomized animals showed alterations in adaptive responses of the maximal oxygen uptake to training. Therefore, the pineal gland must be considered an influential participant in the complex adaptation to exercise and is involved in the improvement of endurance capacity. [source]


Disorders of extreme stress: The empirical foundation of a complex adaptation to trauma

JOURNAL OF TRAUMATIC STRESS, Issue 5 2005
Bessel A. van der Kolk
Children and adults exposed to chronic interpersonal trauma consistently demonstrate psychological disturbances that are not captured in the posttraumatic stress disorder (PTSD) diagnosis. The DSM-IV (American Psychiatric Association, 1994) Field Trial studied 400 treatment-seeking traumatized individuals and 128 community residents and found that victims of prolonged interpersonal trauma, particularly trauma early in the life cycle, had a high incidence of problems with (a) regulation of affect and impulses, (b) memory and attention, (c) self-perception, (d) interpersonal relations, (e) somatization, and (f) systems of meaning. This raises important issues about the categorical versus the dimensional nature of posttraumatic stress, as well as the issue of comorbidity in PTSD. These data invite further exploration of what constitutes effective treatment of the full spectrum of posttraumatic psychopathology. [source]


5-HT1B receptor knockout mice show a compensatory reduction in 5-HT2C receptor function

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2003
Peter G. Clifton
Abstract Although null mutant (,knockout') mice have provided valuable animal models to complement traditional approaches to psychopharmacology, such animals may also show complex adaptations to the induced mutation. Here we demonstrate that serotonin1B (5-HT1B) receptor knockout (KO) mice show adaptations in serotonin2C (5-HT2C) receptor-mediated functions. They show smaller reductions in food intake and locomotor activity in response to administration of 5-HT2C receptor agonists that are not accounted for by altered drug disposition. These effects are not mimicked by pretreatment of wildtype (WT) mice with a 5-HT1B receptor antagonist showing that they result from a longer term adaptation to the loss of 5-HT1B receptor function and not from a short-term interaction between 5-HT1B - and 5-HT2C -mediated functions. In addition, we show that 5-HT1B receptor KO mice have a lowered hypothalamic c-fos response to the administration of 5-HT2C receptor agonists. These results demonstrate that compensatory adaptations to the constitutive loss of 5-HT1B receptors may be an important determinant of the altered response of 5-HT1B KO mice to a variety of pharmacological challenges. [source]


Introduction to "In Focus: Global Change and Adaptation in Local Places"

AMERICAN ANTHROPOLOGIST, Issue 3 2009
Donald R. Nelson
ABSTRACT In recognition of unavoidable changes that human actions are producing in our environment, the term adaptation has become ubiquitous in the environmental and climate-change literature. Human adaptation is a field with a significant history in anthropology, yet anthropological contributions to the burgeoning field of climate change remain limited. This "In Focus" section presents studies of local adaptations to climate variation and change. Each is concerned with current environmental challenges and future environmental change, and each study is placed within a wider context that includes processes of globalization and integration into market economies, formal and informal institutions, and disasters. These studies highlight the challenges involved in understanding complex adaptations under conditions of stress. They also illustrate how anthropologists engage the larger climate-change and human-adaptation discussions and enhance our ability to respond to the challenges of a changing environment. [source]