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Environmental enrichment improves captive animal welfare by reducing stress-related behaviors. Previous studies in a captive colony of stumptail macaques (Macaca arctoides) reported a reduction of aggression, coprophilia, and stereotypic behaviors after an occupational enrichment program; however, the effect on stress hormones such as glucocorticoids has not been investigated yet. The goal of this study was to compare the effect of sex, age, and social rank on changes in fecal glucocorticoid metabolites (fGCM) after applying two kinds of enrichments (occupational vs. musical) in a captive colony of stumptail macaques. We collected 234 fecal samples from 25 stumptail macaques under the following conditions: (1) basal (no enrichment), (2) three weeks of occupational enrichment, and (3) three weeks of relaxing/classical music. The Generalized Estimated Equation Model showed an increase in fGCM levels after the occupational enrichment only in adult subjects (p = 0.003 compared to basal). The fGCM levels reached by the adults after the occupational enrichment was higher than that of juveniles (p = 0.002) and subadults (p = 0.02). Occupational and musical enrichment decreased fGCM levels only in middle-ranking individuals (p < 0.001 and p = 0.013, respectively). No sex differences were found. In conclusion, there were age and rank differences in individuals' physiological reactivity to the effects of environmental enrichment which need to be considered when planning enrichment programs.

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Background: Living in urban places has been associated with a higher risk of psychopathology as well as with altered hypothalamus-pituitary-adrenal (HPA) axis and consequently altered cortisol response, but studies have concentrated mainly in high-income countries population. The role of other hormones such as testosterone, implicated in stress response and with human social behaviors, have not yet been investigated. The aim of this study was to compare symptoms of psychopathology as well as cortisol and testosterone in response to traumatic images between urban and suburban people in a middle-income country. Methods: A sample of 67 women and 55 men (N = 122, 18-45 years) from urban and suburban places of Mexico participated in the study. We quantified salivary cortisol and testosterone in response to images with traumatic and violent content (basal, 15, 30, and 45 min after images). Participants answered a general information questionnaire and the Symptom Checklist-90-R to assess their psychopathological traits. We performed Generalized Estimating Equation Models to analyze hormonal levels and MANOVAs to compare differences in participants' psychopathology symptoms. Area under the curve respect to ground (AUCG) of hormonal levels and sex differences were also compared. Results: Suburban citizens showed no cortisol response, whereas urban people showed a cortisol peak 15 min after the image's exposure; however, suburban people had higher AUCG and basal levels compared to urban ones. Contrastingly, testosterone levels declined in all participants excepting the urban women, who showed no testosterone response. Although similar testosterone profile, AUCG levels were higher in urban than suburban men. Participants living in suburban areas had higher scores of somatizations, obsessive-compulsive, and interpersonal sensitivity, as well as more sleep disorders than participants living in urban areas. Conclusion: This study offers novel evidence about differences in cortisol and testosterone responses to a social stressor and in mental health indicators between a population of urban and suburban citizens, highlighting the impact of urbanization process on physiological and psychological outcomes in a middle-income country.

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The "challenge hypothesis" predicts higher male-male aggressive behavior along with increases in testosterone levels during times of reproductive challenges and social instability. In addition, in some primate species, higher glucocorticoid levels can be observed as well, but this is usually modulated by dominance rank. We studied rank-related aggressive behavior, mating activity, and fecal testosterone and glucocorticoid metabolites (fTm and fGCm) in male stumptail macaques (Macaca arctoides) in order to test some predictions of the "challenge hypothesis". Over a 20-month period, we collected data on aggressive behavior and copulation, as well as fecal samples (n = 700) to quantify fTm and fGCm in seven adult stumptail males living in captivity. During periods of mating activity, male-to-male aggression increased in higher- and middle-ranking males. Neither fTm nor fGCm levels predicted male-to-male aggression. fGCm levels (but not fTm) were positively associated with male-to-female aggression; however, this association was pronounced during periods of mating activity. fGCm levels differed according to social rank, with middle-ranking males having the highest levels. Both hormones were higher during periods of mating activity, but only in higher- and middle-ranking males. Taken together, our findings partially support the challenge hypothesis in a non-seasonal primate and shed some light on the unique social and mating system of the stumptail macaque.

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Abstract Introduction There is a growing need to implement evidence-based psychological treatments for women victims of intimate partner violence (IPV) who commonly experience stress-related disorders such as anxiety, depression, or suicide risk, as well as altered cortisol reactivity. Objective 1. To compare the changes in depressive and anxious symptomatology, quality of life, and cortisol reactivity after two different interventions, Acceptance and Commitment Therapy (ACT, based on psychological flexibility) or Interpersonal Therapy (IPT, based on empowerment) in women exposed to IPV. 2. To compare the changes in relation to the presence of suicide thoughts. Method A clinical sample of 50 women (ages 21-74) randomly assigned to attend ACT or IPT, completed pre- and post-intervention questionnaires about intimate partner violence, quality of life, depression, anxiety, and measurements of salivary cortisol reactivity (basal, 15, 30, and 45 minutes after a cognitive challenge). We used Generalized Estimating Equation Models for data analysis. Results There was a significant improvement post-intervention in all variables, regardless of the type of psychotherapy or the presence of suicide thoughts. Before interventions, women that reported suicide thoughts had severe symptoms of depression, anxiety, worse quality of life, and a cortisol hyper-response profile, in contrast to women without suicide thoughts who had moderate symptoms and no cortisol response. Cortisol response to the cognitive test decreased in all women after both therapies. Discussion and conclusion Although different psychological approach, ACT, and IPT effectively improved mental health, quality of life, and changed cortisol reactivity of women exposed to IPV, including women at suicide risk.

Resumen Introducción Son necesarios tratamientos basados en evidencia para mujeres víctimas de violencia de pareja (IPV), con trastornos relacionados con estrés como ansiedad, depresión y riesgo suicida y alteraciones en la reactividad del cortisol. Objetivo Comparar los cambios en la sintomatología depresiva, ansiosa, calidad de vida y reactividad del cortisol después de aplicar Terapia de Aceptación y Compromiso (ACT, basada en la flexibilidad psicológica) o Terapia Interpersonal (IPT, basada en el empoderamiento) en mujeres expuestas a IPV y compararlos en función al pensamiento suicida. Método Una muestra clínica de 50 mujeres (entre 21 y 74 años) fueron asignadas aleatoriamente a recibir ACT o IPT, completaron antes y después, cuestionarios sobre IPV, calidad de vida, depresión y ansiedad, y mediciones de cortisol (basal, 15, 30 y 45 minutos después de un reto cognitivo) en saliva en respuesta a un reto cognitivo. Utilizamos modelos de Ecuaciones de Estimación generalizada para analizar los datos. Resultados Mejoraron significativamente todas las variables, independientemente del tipo de psicoterapia y del pensamiento suicida. Antes de la intervención, las mujeres con ideación suicida presentaron depresión y ansiedad severas, peor calidad de vida e hiper-respuesta de cortisol, en contraste con las mujeres sin ideación, quienes presentaron síntomas moderados y una respuesta de cortisol plana. El cortisol disminuyó en todas las mujeres después de ambas terapias. Discusión y conclusión Ambas terapias IPT y ACT mejoraron la salud mental y calidad de vida de las mujeres con IPV y modificaron la reactividad del cortisol, incluyendo a las pacientes que reportaron ideación suicida.

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Stress response is associated with increased activity in the hypothalamic-pituitary-adrenocortical axis. Chronic stress-induced elevation in cortisol may alter its own negative regulation with multiple long-term consequences for physical and psychological health. One of the most reliable physical traits associated with mental, apparent physical health, and competitiveness is the degree of facial fluctuating asymmetry. However, to our knowledge there are no studies regarding the relationship between cortisol levels, facial symmetry and male competitiveness, and how cortisol changes after a stressful test depending on these traits. Here, a group of 100 college men were photographed to obtain their facial asymmetry levels. They then, answered the perceived stress scale and the intrasexual competition test and donated two saliva samples (pre-and post-test sample) to measure the change in their cortisol levels after a stressful test. We found that basal cortisol levels were positively correlated with both perceived stress and competitiveness, but not with facial fluctuating asymmetry. Cortisol levels increased in most symmetrical men after a short stressful test, but it decreased in most asymmetrical men. The results suggest differences in endocrine responses according to facial fluctuating asymmetry in men and how these responses could be related to the maintenance of social status.

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RESUMEN Objetivo Analizar los resultados con respecto a la reactividad del cortisol (RC) ante un paradigma de estrés experimental en adultos con o sin algún trastorno psiquiátrico que sufrieron violencia en etapas tempranas de desarrollo (infancia y adolescencia temprana) y con ello proponer una herramienta clínica para el establecimiento de indicadores biológicos de estrés. Métodos Se realizó una revisión sistemática en diversas bases de datos, siguiendo los criterios PRISMA; de un total de 231 artículos, 16 cumplieron los criterios de inclusión y los resultados fueron analizados de manera cualitativa. Resultados A pesar de la heterogeneidad, los resultados sugieren que las personas que sufrieron violencia temprana presentan un patrón de baja RC. Contrariamente, la población que además desarrolló síntomas de trastorno de estrés postraumático y depresión, independientemente del tipo de violencia, mostró incrementada RC. La mayoría de los trabajos se centraron en población que sufrió abuso sexual en la infancia y la mitad de los artículos apoya la hipótesis de que la RC es más pronunciada en hombres que en mujeres. Conclusiones Los resultados de esta revisión nos permiten sugerir que es posible considerar la hiperreactividad del cortisol como un biomarcador para el tratamiento e intervención de población con trastorno de estrés postraumático y depresión que sufrieron violencia temprana. Además, apoyan la evidencia de que sufrir violencia altera la respuesta del estrés y la salud mental a largo plazo. Sin embargo, es necesario realizar más estudios principalmente los que se refieren a la hiporreactividad y a las diferencias de género.

ABSTRACT Objective Analyze results with respect to cortisol reactivity (CR) in experimental stress paradigms in adults with or without a psychiatric disorder who suffered violence in early developmental stages (infancy or early adolescence); and use these results to propose a clinical tool to determine biological stress indicators. Methods A systematic review was conducted using several databases and following PRISMA criteria; of a total of 231 articles, 16 satisfied the inclusion criteria and the results were analyzed qualitatively. Results Despite heterogeneity, the results suggested that the people who suffered violence at an early age present a pattern of low CR. In contrast, people who also developed symptoms of post-traumatic stress disorder and depression, regardless of the type of violence, showed increased CR. The majority of studies focused on people who suffered childhood sexual abuse and half of the articles supported the hypothesis that CR is more pronounced in men than in women. Conclusions The results of this review suggest that cortisol hyperreactivity can be considered a biomarker for treatment and intervention in people with post-traumatic stress disorder and depression who suffered violence at an early age. The results also support evidence that experiencing violence alters stress response and mental health in the long term. However, it is necessary to conduct more studies, in particular studies on hyporeactivity and gender differences.

RESUMO Objetivo Analisar os resultados da reatividade do cortisol segundo um modelo de estresse experimental em adultos com ou sem transtorno psiquiátrico que foram precocemente expostos à violência durante o desenvolvimento (infância e início da adolescência) e propor um instrumento clínico para determinar indicadores biológicos de estresse. Métodos Uma revisão sistemática foi conduzida em diferentes bases de dados conforme os critérios PRISMA. Dos 231 artigos selecionados, 16 satisfizeram os critérios de inclusão. Foi realizada uma análise qualitativa dos resultados. Resultados Apesar de serem heterogêneos, os resultados indicam que adultos com exposição precoce à violência apresentam baixa reatividade do cortisol. De maneira oposta, os indivíduos que desenvolveram sintomas de transtorno de estresse pós-traumático e depressão, independentemente do tipo de violência sofrida, apresentaram elevada reatividade do cortisol. A maioria dos estudos se centrou em vítimas de abuso sexual na infância e, em metade dos artigos, sustentou-se a hipótese de que a reatividade do cortisol é mais acentuada no sexo masculino que no feminino. Conclusões Os resultados deste estudo de revisão apontam que se pode considerar a hiper-reatividade do cortisol como biomarcador para o tratamento e a intervenção de pacientes que foram expostos precocemente à violência e que apresentam transtorno de estresse pós-traumático e depressão. Além disso, é reforçada a evidência de que sofrer violência afeta a resposta ao estresse e a saúde mental a longo prazo. Porém, fazem-se necessários mais estudos, sobretudo investigando hiporreatividade e diferenças de gênero.

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We studied if testosterone and estradiol concentrations are associated with specific female waist-to-hip ratios (WHRs) and body mass indices (BMIs). Participants were 187 young women from which waist, hips, weight, and height were measured. In addition, participants informed on which day of their menstrual cycle they were and provided a 6 mL saliva sample. Ninety-one of them were in the follicular phase and 96 in the luteal phase. Only in the fertile phase of the menstrual cycle we found a significant interaction between testosterone and estradiol affecting WHR (b ± s.e. = -0.000003 ± 0.000001; t 94 = -2.12, adjusted R (2) = -0.008, P = 0.03). Women with the highest levels of both hormones had the lowest WHRs, while women with low estradiol and high testosterone showed the highest WHRs. BMI significantly increased as testosterone increased in female in their nonfertile days.

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Some environmental variables determining seasonal reproduction in mammals are temperature, humidity, food availability, and photoperiod. Among these, photoperiod is considered the main regulator of primates' seasonal reproduction, thus the latitudinal distribution of primate populations is a key factor determining the appearance of seasonal reproduction. The present work presents supporting discrete seasonality in male stump-tailed macaques (Macaca arctoides). We investigated whether semen quality and testosterone covaried with Mexico City's photoperiod and relative humidity by analyzing variations in the portions that form the ejaculate: the seminal liquid, the seminal coagulum, and the copulatory plug. Five male adult stump-tailed macaques were electroejaculated once a month, obtaining three semen samples per male, from August 2011 to July 2012 (except for December 2011) (n = 165). Our results showed that stump-tailed macaque sperm counts were significantly different between the portions of the ejaculate. The seminal coagulum contained the significantly largest number of spermatozoids, followed by the copulatory plug and the seminal fluid. Photoperiod and relative humidity had major influence on the sperm count in the seminal coagulum and the testosterone concentrations. Testosterone reached its highest values around the time when days and nights lasted the same hours, decreasing when days either grew longer or became shorter. Concerning relative humidity, sperm counts in the seminal coagulum were highly variable on dry days, but decreased as the relative humidity increased. We conclude that stump-tailed macaques have a discrete seasonality, occurring in spring and fall when macaques' reproductive condition and readiness for postcopulatory intrasexual competition increase.

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Human reproduction involves, as in many other mammal species, a sexual selection process. Some of the features chose in a reproductive mate are intelligence, reliability, health, access to resources and others. However, the ultimate individuals' decision depends on her or his reproductive strategy. Several works have demonstrated that human beings cannot be characterized by a single strategy; people can decide for a long-term commitment mating, a short-term mating or both. However, there are some psychobiological aspects that underlie such decision making and apparently they are universal for human beings. In this review we present results, including our own, which illustrate the set of characteristics that are involved in human mate choice. In order to acquire an appropriate understanding of human behavior, it is necessary to consider those psychological adaptations which operate at both conscious and unconscious levels, evolved to deal with the most elementary demands to survive and reproduce.

La reproducción en los seres humanos, al igual que en otras muchas especies, implica un proceso de selección sexual que incluye la evaluación de factores como la inteligencia, la confiabilidad, la salud, la posibilidad de aportar recursos y las características físicas, entre otras. Sin duda, la decisión de la elección depende de la estrategia reproductiva que cada individuo elija pues diversos estudios sobre selección sexual humana muestran que las personas hacen uso de más de una estrategia reproductiva, lo que explica por qué algunos individuos prefieren tener varias relaciones a corto plazo, otros se deciden por una sola relación a largo plazo y otros más mantienen ambas, es decir, una a largo plazo y varias a corto plazo. Como consecuencia, las características que cada uno podría buscar en sus parejas potenciales resultan ser muy diversas. Sin embargo, existen algunos factores biológicos que subyacen a la toma de decisiones y que son aparentemente universales. En esta revisión presentamos los resultados obtenidos en algunos trabajos, incluyendo los nuestros, con la finalidad de dar a conocer, desde la perspectiva biológica, cuáles características resultan imprescindibles para seleccionar una pareja y porqué. Desde luego, sin perder de vista que para conseguir un mejor entendimiento de la conducta humana es necesario considerar que las adaptaciones psicológicas en los seres humanos, las cuales operan de forma consciente o inconsciente, están encaminadas a resolver los problemas más elementales de sobrevivencia y reproducción.

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In addition to gametes, mammalian internal fertilisation has required the evolution of assorted anatomical, physiological and biochemical devices to deal with intra- and inter-sexual conflict such as sperm competition and female cryptic choice respectively. The seminal coagulum of primates and other mammals is viewed as one of such devices. Among primates, the seminal coagulum characteristically occurs in multi-male and multi-female species, leading us to suppose that it intervenes in sperm competition. However, it can also provide cues to the female reproductive tract about male desired or undesired traits, and therefore deter or favour sperm survival and migration. The present work investigates whether the seminal coagulum of the black-handed spider monkey enhances sperm fertilisation chances by improving the female reproductive tract conditions, and if the female reproductive tract is 'blind' to semen or behaves selectively towards ejaculates of different males. A series of artificial inseminations were done in five females, using the ejaculates of three different males, one at a time, and measuring the presence of distinct types of sperm inside the uteri at 10, 30 and 60 min following the insemination. The presence of coagulum, menstrual phase, and male and female identity only affected fast, straight-moving sperm, with larger amounts of fast sperm appearing inside the uteri when ejaculates had seminal coagulum, as well as when in the periovulatory phase. There was great intra-uterine fast-sperm variation regarding which male's semen inseminated which female. The results provide evidence to account for sexual conflict in the spider monkey as well as a methodological approach to this kind of study.

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El sistema olfatorio de los mamíferos se ha especializado en la percepción de componentes químicos que regulan una gran diversidad de funciones. Uno de los componentes químicos que más utilizan las distintas especies es la feromona, cuyos efectos se pueden encontrar en el ámbito fisiológico o conductual, dependiendo del mensaje que se emita y del contexto en el cual se perciba.El uso de las feromonas en la comunicación química de los mamíferos tiene importantes funciones reguladoras de procesos reproducticos, que pueden afectar las interacciones sociales dentro de las poblaciones. Las feromonas que más emplean los mamíferos se encuentran en la orina y en las secreciones vaginales. La percepción de estos componentes químicos se lleva a cabo por el epitelio olfatorio y el órgano vomeronasal, que establecen conexiones neurales con diferentes núcleos cerebrales vinculados con la regulación del proceso reproductivo y las emociones. Sin embargo, hay controversia sobre la presencia de las feromonas en los antropoides del Viejo Mundo y en los seres humanos. En los primates, como los prosimios y los monos del Nuevo Mundo, se acepta su función en las conductas de marcaje territorial, en el reconocimiento entre conespecíficos y en la conducta sociosexual. En los primates catarrinos, en los póngidos y en los seres humanos se ha generado controversia sobre la participación de las feromonas en la atracción sexual. En primer lugar, debido a que esos grupos de primates muestran una disminucion de la región olfatoria, tanto nasal como cerebral, en comparación con el resto de los mamíferos. En segundo lugar, porque hasta ahora no se ha demostrado la funcionalidad del órgano vomeronasal, supuestamente especializado en la percepción de las feromonas en los demás mamíferos, que se considera como vestigial en los monos catarrinos y en los simios. Hay algunos trabajos sobre los seres humanos que muestran que dicho órgano no es completamente vestigial, como se consideraba, sino que es una estructura especializada en la percepción de feromonas, capaz de promover cambios fisiológicos dependientes del sexo.

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