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Environment is known to substantially alter mental state and behaviour across the lifespan. Biological barriers such as the blood-brain barrier (BBB) and gut barrier (GB) are major hubs for communication of environmental information. Alterations in the structural, social and motor environment at different stages of life can influence function of the BBB and GB and their integrity to exert behavioural consequences. Importantly, each of these environmental components is associated with a distinct immune profile, glucocorticoid response and gut microbiome composition, creating unique effects on the BBB and GB. These barrier-environment interactions are sensitive to change throughout life, and positive or negative alterations at critical stages of development can exert long-lasting cognitive and behavioural consequences. Furthermore, because loss of barrier integrity is implicated in pathogenesis of mental disorders, the pathways of environmental influence represent important areas for understanding these diseases. Positive environments can be protective against stress- and age-related damage, raising the possibility of novel pharmacological targets. This review summarizes known mechanisms of environmental influence--such as social interactions, structural complexity and physical exercise --on barrier composition, morphology and development, and considers the outcomes and implications of these interactions in the context of psychiatric disorders., Environment, barriers and the brain Every organism is shaped by their surroundings through constant perception, consumption and physical engagement with environmental features such as chemical makeup, social targets, structural complexity [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.socscimed.2010.07.045 Byline: W. Thomas Boyce (a), Pamela K. Den Besten (b), Juliet Stamperdahl (c), Ling Zhan (b), Yebin Jiang (d), Nancy E. Adler (b), John D. Featherstone (b) Abstract: The studies reported here examines stress-related psychobiological processes that might account for the high, disproportionate rates of dental caries, the most common chronic disease of childhood, among children growing up in low socioeconomic status (SES) families. In two 2004-2006 studies of kindergarten children from varying socioeconomic backgrounds in the San Francisco Bay Area of California (Ns = 94 and 38), we performed detailed dental examinations to count decayed, missing or filled dental surfaces and microtomography to assess the thickness and density of microanatomic dental compartments in exfoliated, deciduous teeth (i.e., the shed, primary dentition). Cross-sectional, multivariate associations were examined between these measures and SES-related risk factors, including household education, financial stressors, basal and reactive salivary cortisol secretion, and the number of oral cariogenic bacteria. We hypothesized that family stressors and stress-related changes in oral biology might explain, fully or in part, the known socioeconomic disparities in dental health. We found that nearly half of the five-year-old children studied had dental caries. Low SES, higher basal salivary cortisol secretion, and larger numbers of cariogenic bacteria were each significantly and independently associated with caries, and higher salivary cortisol reactivity was associated with thinner, softer enamel surfaces in exfoliated teeth. The highest rates of dental pathology were found among children with the combination of elevated salivary cortisol expression and high counts of cariogenic bacteria. The socioeconomic partitioning of childhood dental caries may thus involve social and psychobiological pathways through which lower SES is associated with higher numbers of cariogenic bacteria and higher levels of stress-associated salivary cortisol. This convergence of psychosocial, infectious and stress-related biological processes appears to be implicated in the production of greater cariogenic bacterial growth and in the conferral of an increased physical vulnerability of the developing dentition. Author Affiliation: (a) University of British Columbia, Vancouver, BC, Canada (b) University of California, San Francisco, USA (c) University of California, Berkeley, USA (d) University of Michigan, USA

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.socscimed.2009.12.006 Byline: Patrick West (a), Helen Sweeting (a), Robert Young (a), Shona Kelly (b) Abstract: This paper examines the relative importance of family socioeconomic status (SES) and school-based peer hierarchies for young people's psychoneuroendocrine response, represented by cortisol level. Data are drawn from a study of 2824, 15-year-olds in 22 Scottish secondary schools in 2006 who provided information on family SES (parental occupation, material deprivation and family affluence) and social position in school hierarchies, together with two morning salivary cortisol samples. School social position was assessed by participants placing themselves on seven 'ladders', from which three factors were derived, termed scholastic, peer and sports hierarchies. Controlling for confounds, there was little or no variation in cortisol by any SES measure. By contrast, each school hierarchy was independently associated with cortisol, but in different ways. For the scholastic hierarchy, an inverse linear relationship was found for females, cortisol increasing with lower position. For peer hierarchy, an opposite (direct) linear relationship occurred for males, while for females elevated cortisol was associated only with 'top' position. For sports, elevated cortisol among males was associated with 'bottom' position, among females with all except the 'top'. These results are interpreted in the context of Sapolsky's () predictions for stress responses to hierarchical position in stable and unstable social systems, the former represented by the scholastic hierarchy involving elevated cortisol in lower positions, the latter by peer hierarchy with elevated cortisol in higher positions. Overall, the results highlight the greater importance of school-based peer groups than family SES for young people's psychoneuroendocrine response. Author Affiliation: (a) MRC Social & Public Health Sciences Unit, 4, Lilybank Gardens, Glasgow G12 8RZ, UK (b) Centre for Intergenerational Health Research, University of South Australia, Division of Health Sciences, Social Epidemiology Unit, P4-18, City East Campus, North Terrace, Adelaide, SA 5001, Australia

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2008.09.031 Byline: Lee Koren, Eli Geffen Abstract: Androgens have been linked to social behaviour in males across many vertebrate species. Despite the lack of gender specificity in steroid hormones, the association of androgens with behaviour in females remains obscure. We analysed steroid hormone levels in male and female rock hyraxes, Procavia capensis, and found strong ties between androgens and cortisol in females but not in males, despite the latter being the sex that usually shows this association. In the past we have shown that both female and male hyraxes have similar testosterone levels. In the present work, we found a significant interaction between testosterone levels and social status. Testosterone levels differed only between lower-ranking males and females, with females showing higher levels. Furthermore, dominant females had significantly lower testosterone levels than subordinate females. No association was detected between litter size and female rank, testosterone or cortisol levels. At this stage, we can only hypothesize that the assumed detrimental effects of high circulating androgen levels, reflected in the hair samples, influence the reproductive output or the offspring survival of subordinate females in some other ways, which require further investigation to be revealed. Author Affiliation: Department of Zoology, Tel Aviv University, Israel Article History: Received 28 February 2008; Revised 22 April 2008; Accepted 22 September 2008 Article Note: (miscellaneous) MS. number: 08-00127R

Abstract Background: A once-daily fixed combination of hydroquinone, tretinoin, and fluocinolone acetonide (Tri-luma) is a newly available treatment for melasma. Objective: To assess cost-effectiveness of triple combination therapy (TCT) applied [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2004.06.016 Byline: M. Clara P. Amorim, Vitor C. Almada Abstract: Social status in lek-breeding species is highly correlated with mating success. Reproductive failure of subordinates may be caused either by direct aggression by dominant males or by induced physiological changes. We hypothesized that recent social status (winning or losing an encounter with another male) affects the production of courtship sounds in male Mozambique tilapia, Oreochromis mossambicus, in the absence of dominant males. We staged dyadic encounters between males and subsequently allowed full access to a female to either the winner or the loser (one fish per dyad). We minimized possible effects of social experience by isolating the subject males before the experiments. All males courted the females but winners produced more courtship sounds than losers and showed significantly shorter courtship latencies and longer courtship durations. The sounds of winners had longer pulse durations and lower peak frequencies. Male size and condition factor, fighting latency and duration, and number of escalated agonistic acts were not correlated with number of sounds or any of the courtship parameters measured. Differences between winners and losers in courtship were probably related to transient physiological changes induced by the encounter outcome, such as changes in levels of circulating monoamines, cortisol and androgens, which can modulate courtship behaviour including sound production. We suggest that in nature the outcome of recent social interactions between males may affect the production of courtship sounds and courtship behaviour in general from the early stages of hierarchy formation. Author Affiliation: Unidade de Investigacao em Eco-Etologia, Instituto Superior de Psicologia Aplicada, Portugal Article History: Received 7 January 2004; Revised 27 February 2004; Accepted 24 June 2004 Article Note: (miscellaneous) MS. number: 7950