1,721,013 research outputs found
Influence of kinship and familiarity on social and reproductive behavior of female mongolian gerbils
No full textAlteration of behavioral and endocrinological reactivity induced by 3 brief social defeats in rats: Relevance to human psychopathology.
No full textIn the realm of animal models of psychopathology, social stress based procedures rely on robust theoretical prerequisites to meet construct validity criteria for the target syndromes. In order to further assess the relevance for human psychopathology of a social defeat based model in rats, known to elicit consistent behavioral and hormonal changes, we expanded its characterization on the basis of both behavioral parameters and peripheral biomarkers thought to be pertinent for clinical symptoms. Rats were subjected to 3 daily social defeat experiences that shortly thereafter led to the insurgence of defensive behaviors, anhedonia, and body weight loss. HPA axis showed an activated response when rats were sampled as early as after the first social defeat experience, while none of the peripheral immune, metabolic, and neurotrophic factors examined were concurrently affected. With the aim of determining the long-term bio-behavioral sequelae of the social defeat experience, rats were assessed also3 weeks after the social defeats. At this time, behavioral changes were still observed, including decreased general activity and sociality in a social avoidance test, increased immobility and decreased escape responses in a forced swim test. These alterations were not paralleled by alterations in anhedonia nor HPA axis responses from controls, nor where evident changes in the humoral component of the immune response nor in brain derived neurotrophic factor levels, whereas a substantial increase in leptin levels was observed in previously socially defeated rats compared to control. Overall these data depict a very complex set of alterations induced both acutely and long-term by social stress in endocrinological and behavioral reactivity of rats
Gene x Environment mouse models for mood disorders.
No full textMuch of the impact of genes on mood disorders likely depends on interactions between genes and the environment. Recent studies demonstrating an
interaction between specific genes and life stressful events (early and/or adult) in the modulation of several mood disorders (e.g., serotonin transporter and brain-derived neurotrophic factor genes) have compelled researchers to incorporate information about adverse environmental experiences into the study of genetic risk factors; these same gene-by-environment (G×E) interactions have been identified in mouse models. Notably, G×E not yet
described in humans (e.g., serotonin 1A receptor gene) have been uncovered, providing helpful indications to discover similar interactions in humans.
Accurate knowledge of the modality of expression of gene-by-stress interaction may help design prevention protocols aimed at identifying susceptibility to mood disorders on the basis of genetic predisposition and exposure to environmental stressful conditions, thus providing patients with appropriate pharmacological and psychological support
Beta-adrenergic receptors control brown adipose UCP1 tone and cold response without affecting its circadian rhythmicity
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Social defeat-induced contextual conditioning differentially imprints behavioral and adrenal reactivity: A time-course study in the rat
No full textThe present experiments were based on the rat resident-intruder paradigm and aimed at better understanding the long-term conditioning properties of this social stress model. Intruders were exposed to aggressive conspecifics residents. During 3 daily encounters, intruders were either defeated or threatened by residents, providing the defeated-threatened (DT) and threatened-threatened (TT) groups respectively, or exposed to a novel empty cage (EC). The effect of such exposures was assessed in 3 separate experiments 8, 14, or 21 days following the last session on both behavior and hypothalamus-pituitary-adrenal (HPA) axis parameters. A specific and persistent behavioral conditioning due to social defeat but also to the sole social threat experience was observed as defensive behaviors and anxiety-like behaviors were observed respectively in DT and TT rats, highlighting a lack of habituation for the conditioning properties of this social stressor. On the other hand, at the earlier time points examined a less specific activation of the HPA axis parameters was found, starting to show habituation at day 21 in EC but not in DT or TT rats. These data give further support to the lasting effects of this social stress model, bestowing a special emphasis upon the impact of its psychological component and upon the relevance of its development and maintenance over time. (C) 2007 Elsevier Inc. All rights reserved
Social defeat-induced contextual conditioning differentially imprints behavioral and adrenal reactivity: a time-course study in the rat.
No full textThe present experiments were based on the rat resident–intruder paradigm and aimed at better understanding the long-term conditioning properties of this social stress model. Intruders were exposed to aggressive conspecifics residents. During 3 daily encounters, intruders were either defeated or threatened by residents, providing the defeated–threatened (DT) and threatened–threatened (TT) groups respectively, or exposed to a novel empty cage (EC). The effect of such exposures was assessed in 3 separate experiments 8, 14, or 21 days following the last session on both behavior and hypothalamus–pituitary–adrenal (HPA) axis parameters. A specific and persistent behavioral conditioning due to social defeat but also to the sole social threat experience was observed as defensive behaviors and anxiety-like behaviors were observed respectively in DT and TT rats, highlighting a lack of habituation for the conditioning properties of this social stressor. On the other hand, at the earlier time points examined a less specific activation of the HPA axis parameters was found, starting to show habituation at day 21 in EC but not in DT or TT rats. These data give further support to the lasting effects of this social stress model, bestowing a special emphasis upon the impact of its psychological component and upon the relevance of its development and maintenance over time
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