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Enduring Effects (enduring + effects)
Selected AbstractsCircadian Timing of Ethanol Exposure Exerts Enduring Effects on Subsequent Ad Libitum Consumption in C57 MiceALCOHOLISM, Issue 7 2009Jennifer L. Trujillo Background:, There is a daily rhythm in the voluntary intake of ethanol in mice, with greatest consumption in the early night and lowest intake during the day. The role of daily timing of ethanol exposure on the development and control of long-term ethanol self-administration has been neglected. The present study examines these issues using C57BL/6J mice. Methods:, Mice were repeatedly exposed to 10% ethanol for 2 hours early in the night or day for several weeks. Subsequently, ethanol was available at the opposite time (Expt 1) or 24 hours daily (Expts 1 and 2). Lick sensors recorded the patterns of drinking activity in Experiment 2. Results:, Mice exposed to ethanol during the night drink more than mice exposed during the day. Prior history did not affect ethanol intake when the schedule was reversed. Under 24-hour exposure conditions, mice with a history of drinking during the night consumed significantly more than mice drinking during the day. The circadian patterns of drinking were not altered. Conclusions:, These results demonstrate that the daily timing of ethanol exposure exerts enduring effects of self-administration of ethanol in mice. Understanding how circadian rhythms regulate ethanol consumption may be valuable for modifying subsequent intake. [source] Chronic social stress in adolescence influenced both amphetamine conditioned place preference and locomotor sensitizationDEVELOPMENTAL PSYCHOBIOLOGY, Issue 5 2008I. Z. Mathews Abstract We previously reported that chronic social stress (SS) in adolescence, but not in adulthood, increased the locomotor-activating effects of nicotine in females, and not males, when tested in adulthood. However, SS rats had decreased locomotor response to nicotine when tested in adolescence. Here, we investigated age-related changes in the effects of SS on both conditioned place preference (CPP) and locomotor sensitization to amphetamine. In the CPP experiment, SS females tested in adolescence had increased preference for the 1.0 mg/kg dose of amphetamine, whereas SS rats of both sexes showed a decrease in CPP for the 0.5 mg/kg dose when tested as adults. Irrespective of time of testing, SS males and females had enhanced locomotor sensitization compared to controls. Thus, adolescent SS produced both immediate and enduring effects on behavioral responses to amphetamine, likely by altering the development of the mesocorticolimbic dopamine system, which holds implications for vulnerability to addiction. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 451,459, 2008. [source] REVIEW: Consilient research approaches in studying gene × environment interactions in alcohol researchADDICTION BIOLOGY, Issue 2 2010Kenneth J. Sher ABSTRACT This review article discusses the importance of identifying gene-environment interactions for understanding the etiology and course of alcohol use disorders and related conditions. A number of critical challenges are discussed, including the fact that there is no organizing typology for classifying different types of environmental exposures, many key human environmental risk factors for alcohol dependence have no clear equivalents in other species, much of the genetic variance of alcohol dependence in human is not ,alcohol specific', and the potential range of gene-environment interactions that could be considered is so vast that maintaining statistical control of Type 1 errors is a daunting task. Despite these and other challenges, there appears to be a number of promising approaches that could be taken in order to achieve consilience and ecologically valid translation between human alcohol dependence and animal models. Foremost among these is to distinguish environmental exposures that are thought to have enduring effects on alcohol use motivation (and self-regulation) from situational environmental exposures that facilitate the expression of such motivations but do not, by themselves, have enduring effects. In order to enhance consilience, various domains of human approach motivation should be considered so that relevant environmental exposures can be sampled, as well as the appropriate species to study them in (i.e. where such motivations are ecologically relevant). Foremost among these are social environments, which are central to the initiation and escalation of human alcohol consumption. The value of twin studies, human laboratory studies and pharmacogenetic studies is also highlighted. [source] Nature-Society Interactions in the Pacific IslandsGEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 4 2003Patrick D. Nunn ABSTRACT This paper focuses on nature,society interactions in the Pacific Islands before European contact about 200 years ago. It argues that the character of early interactions was decided by both the nature of a particular island environment and the intentions of the human settlers. Throughout the pre-European contact human history of the Pacific Islands, environmental changes of extraneous cause have been the main control of societal and cultural change. This environmental determinist view is defended using many examples. The contrary (and more popular) cultural determinist view of societal change in the Pacific Islands is shown to be based on largely spurious data and argument. A key example discussed is the ,AD 1300 Event', a time of rapid temperature and sea-level fall which had severe, abrupt and enduring effects on Pacific Island societies. It is important to acknowledge the role of environmental change in cultural transformation in this region. [source] Intrahippocampal administration of BDNF in adult rats affects short-term behavioral plasticity in the Morris water maze and performance in the elevated plus-mazeHIPPOCAMPUS, Issue 7 2004Francesca Cirulli Abstract The present study evaluated the effects of a single intrahippocampal administration of brain-derived neurotrophic factor (BDNF) on memory retention in a water maze. Adult rats were trained in a water maze (acquisition phase, day 1). Immediately after the last training trial subjects were injected in the right hippocampus with either BDNF (24 ,g) or phosphate-buffered saline (1 ,l). On day 2, all subjects were tested for memory retention in a probe trial and were subsequently tested for reversal learning. While no differences emerged in the probe trial, BDNF-treated subjects showed a shorter latency and a shorter path length to reach the platform during the reversal phase. A significant difference in their "turn angle" and in their swim paths suggests that they might have used a different search strategy compared with controls. Moreover, all subjects also underwent an elevated-plus maze test. BDNF-treated-animals showed a clear tendency to spend a greater amount of time in the open arms and a significantly higher frequency of grooming behavior and of the stretched-attend posture in this maze area, but no differences in locomotion. Overall, these results indicate that administration of BDNF improves performance in a spatial memory task and has enduring effects on emotional behavior. © 2004 Wiley-Liss, Inc. [source] Earlier stress exposure and subsequent major depression in aging womenINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 1 2010Stephanie Kasen Abstract Objective Despite evidence that stress exposure earlier in the life course may have long-term consequences for psychopathology, most models of vulnerability for late life depression are limited to current stressors or to retrospective reports of stress history. This study estimates the influences of earlier stressors assessed longitudinally on subsequent major depressive disorder (MDD) in women at average age 60 (range 50,75). Method MDD, negative life events (NLE), and marital stress were assessed multiple times in a community-based sample of 565 women followed for three decades. Adverse events experienced in childhood also were assessed prior to outcome. Results Greater childhood adversity, earlier high levels of NLE and marital stress, and a more rapid increase in marital stress over time elevated the odds of MDD at average age 60 independent of all stressors and other salient risk factors. Childhood adversity was mediated in part by intervening risks. Prior depression, earlier poor health status, a more rapid deterioration in health with age, and current disability owing to physical problems also were related independently to later MDD. Conclusions These findings support the enduring effects of earlier stress burden on MDD in women into old age and, in light of the increasing proportion of older women in the population, have important clinical implications for identification and treatment of those at risk for depression. Findings also underscore the need to develop resources to counteract or buffer similar stress exposure in younger generations of women. Copyright © 2009 John Wiley & Sons, Ltd. [source] Altered Mesencephalic Dopaminergic Populations in Adulthood as a Consequence of Brief Perinatal Glucocorticoid ExposureJOURNAL OF NEUROENDOCRINOLOGY, Issue 8 2005S. McArthur Abstract Early exposure to stressors is strongly associated with enduring effects on central nervous system function, but the mechanisms and neural substrates involved in this biological ,programming' are unclear. This study tested the hypothesis that inappropriate exposure to glucocorticoid stress hormones (GCs) during critical periods of development permanently alters the mesencephalic dopaminergic populations in the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc). Using a rat model, the synthetic GC dexamethasone was added to the maternal drinking water during gestational days 16,19 or over the first week of postnatal life. In adulthood, the effects upon tyrosine hydroxylase immunopositive (TH+) cell numbers in the midbrain, and monoamine levels in the forebrain, of the adult offspring were assessed and compared with control offspring whose dams received normal drinking water. In the VTA, both prenatal and postnatal dexamethasone treatment increased TH+ cell numbers by approximately 50% in males and females. Although prenatal dexamethasone treatment also increased TH+ cell numbers in the SNc by 40,50% in males and females, postnatal treatment affected females only by increasing TH+ cell numbers by approximately 30%. In comparison, similar changes were not detected in the monoamine levels of the dorsolateral striatum, nucleus accumbens or infralimbic cortex of either males or females, which is a feature likely to reflect adaptive changes in these pathways. These studies demonstrate that the survival or phenotypic expression of VTA and SNc dopaminergic neurones is profoundly influenced by brief perinatal exposure to GCs at times when endogenous levels are normally low. These findings are the first to demonstrate permanent changes in the cytoarchitecture within midbrain dopamine nuclei after perinatal exposure to stress hormones and implicate altered functionality. Thus, they have significance for the increasing use of GCs in perinatal medicine and indicate potential mechanisms whereby perinatal distress may predispose to the development of a range of psychiatric conditions in later life. [source] Circadian Timing of Ethanol Exposure Exerts Enduring Effects on Subsequent Ad Libitum Consumption in C57 MiceALCOHOLISM, Issue 7 2009Jennifer L. Trujillo Background:, There is a daily rhythm in the voluntary intake of ethanol in mice, with greatest consumption in the early night and lowest intake during the day. The role of daily timing of ethanol exposure on the development and control of long-term ethanol self-administration has been neglected. The present study examines these issues using C57BL/6J mice. Methods:, Mice were repeatedly exposed to 10% ethanol for 2 hours early in the night or day for several weeks. Subsequently, ethanol was available at the opposite time (Expt 1) or 24 hours daily (Expts 1 and 2). Lick sensors recorded the patterns of drinking activity in Experiment 2. Results:, Mice exposed to ethanol during the night drink more than mice exposed during the day. Prior history did not affect ethanol intake when the schedule was reversed. Under 24-hour exposure conditions, mice with a history of drinking during the night consumed significantly more than mice drinking during the day. The circadian patterns of drinking were not altered. Conclusions:, These results demonstrate that the daily timing of ethanol exposure exerts enduring effects of self-administration of ethanol in mice. Understanding how circadian rhythms regulate ethanol consumption may be valuable for modifying subsequent intake. [source] | ||||||||||||||||