Glucocorticoid reactivity is often used as a biomarker of emotional stress status in animals and man. Likewise, behavioural responses of individuals to standardized stresses are also widely used to assess the magnitude of perceived stress. Unfortunately, there is little evidence that widely used physiological measures and widely used behavioural measures yield similar, or even correlated, results. The current study provides an explicit test of the relationship between the two approaches. Dwarf hamsters (Phodopus campbelli) were subjected to a standardized, on-back restraint in a socially subordinate position and had plasma samples drawn under brief, home-cage, isoflurane anesthesia to quantify cortisol before and after the acute stress. Individual responses were transformed into parameters describing the absolute change in cortisol, the proportional changes in cortisol, and the overall exposure to cortisol across stress and recovery. There was exceptional individual variability in cortisol responses to the standardized stressor, including monotonic declines, and cluster analysis failed to effectively partition between-individual variation by sex, age, or housing conditions, for any parameter. Next, physiological measures, and a battery of behavioural tests routinely used to assess, anxiety, stress, and emotionality differences, as well as resistance to capture and intruder aggression, were combined in an expanded population including individuals from genetic lines selected to increase or decrease cortisol concentration. In general, dwarf hamsters showed less neophobia than is typical of laboratory mice and rats (e.g. animals quickly dropped from the elevated plus maze). In addition, results were combined to create behavioural indices by orienting each test score relative to an emotionality continuum and combining tests based on, a priori, expectations of similarity. Multivariate regression failed to detect covariation between physiological and behavioural measures, despite the large number of parameters describing those responses. Although the experimental design did not include replication, or comparison of physiological responses to different stressors, it was clear that behavioural and physiological responses were neither interchangeable nor statistically associated. Thus, results challenge widespread assumptions about the interaction between the glucocorticoid response to stress, and the manifestation of that stress through alterations in behaviour. Additional research exploring physiology-behaviour associations in genetically diverse populations is warranted. / Thesis (Ph.D, Biology) -- Queen's University, 2009-02-11 12:29:33.22

Introduktion: Påverkan av stress på immunförsvarsresponsen kan leda till mer kraftfullt inflammatoriskt svar som leder till parodontal vävnadsnedbrytning. Enligt hypotesen kan psykologiska faktorer, såsom stress, i kombination med förändrat munhygienbeteende ha betydelse för parodontala sjukdomstillstånd (Genco et al. 1998). Syfte: Att beskriva samband mellan stress och parodontal sjukdom. Frågeställning: Vilka samband föreligger mellan stress och parodontal sjukdom? Metod: Litteraturstudie Resultat: Föreliggande litteraturstudie visar att det kan föreligga samband mellan stress och parodontal sjukdom genom förändrat munhygienbeteende och genom förhöjda nivåer av stresshormoner, såsom cortisol och dehydroepiandrosterone (DHEA) i saliv, gingivalvätska och blodserum. Konklusion: Det kan föreligga samband mellan stress och parodontal sjukdom genom förändrat munhygienbeteende samt genom förhöjda nivåer av stresshormoner i saliv, gingivalvätska och blodserum. Dock kan inga definitiva slutsatser fastställas med denna litteraturstudie.

People who stutter (PWS) tend to have increased levels of anxiety compared to people who do not stutter (PWNS), particularly in social situations (Messenger, Onslow, Packman, & Menzies, 2004). In addition, children who stutter (CWS) as young as 3 years of age reportedly have more negative communication attitudes than their fluent peers, and these attitudes appear to worsen with age and stuttering severity (De Nil & Brutten, 1990, 1991; Vanryckeghem, Brutten, & Hernandez, 2005). The present study sought to examine generalized anxiety and communication apprehension in preschool CWS. Seven CWS aged between 3;3 and 4;11 years, and seven sex and age-matched children who do not stutter (CWNS) provided salivary cortisol samples at three distinct sampling times across a one-week period. They additionally provided a conversational speech sample, and were administered the Communication Attitude Test for Preschool and Kindergarten Children Who Stutter (Vanryckeghem & Brutten, 2007). Parents were required to complete the Preschool Anxiety Scale (Spence & Rapee, 1999) to provide estimates of their child's anxiety level. Results revealed no significant differences between CWS and CWNS in generalized anxiety or communication apprehension. No relationships were found between stuttering severity and generalized anxiety or communication apprehension either. Thus, it is concluded that generalized anxiety and communication apprehension are not associated with early childhood stuttering. Any changes in anxiety levels are likely to occur with increased chronological age and stuttering chronicity.

Doctor of Philosophy / School of Family Studies and Human Services / Briana S. Nelson Goff / Several courses in higher education may utilize trauma-related content material as a part of the curriculum. In order to reduce the potential for experiencing secondary traumatic stress in college students, it has been recommended that instructors of such courses be purposeful and cautious with the use of trauma-related materials in the classroom (Cunningham, 2004; Kostouros, 2008). Most recommendations for implementation of these materials are based on theory, and there are few empirical studies that examine actual student reactions to trauma-related content. In the current study, both salivary cortisol and mixed-method survey data were obtained from undergraduate students enrolled in an undergraduate trauma course across three semesters. Results indicated that exposure to higher levels of adverse childhood experiences were significantly related to higher cortisol levels after participating in a course lecture with high levels of trauma content. Generally, students reported favorable views and positive experiences in the course overall. Students with higher levels of lifetime exposure to traumatic events had significantly higher levels of emotional reactions to the course. Qualitative results indicated a range of emotional reactions to the course content, with both positive and negative effects. Implications for teaching practice, policy, and future research are discussed.

Submitted by LETÍCIA VINHAS RAMPIM null (letvinhas@gmail.com) on 2017-06-13T19:28:37Z No. of bitstreams: 1 dissertação-leticia-formatada final4.pdf: 1508884 bytes, checksum: 9d9853dc143b3ceb59ae2e648b68d32a (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-06-19T12:38:09Z (GMT) No. of bitstreams: 1 rampim_lv_me_araca.pdf: 1508884 bytes, checksum: 9d9853dc143b3ceb59ae2e648b68d32a (MD5) / Made available in DSpace on 2017-06-19T12:38:09Z (GMT). No. of bitstreams: 1 rampim_lv_me_araca.pdf: 1508884 bytes, checksum: 9d9853dc143b3ceb59ae2e648b68d32a (MD5) Previous issue date: 2017-05-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O enriquecimento ambiental consiste em técnicas para modificação do ambiente físico ou social de animais mantidos em cativeiro. Utilizado desde a década de 1970 para promover o bem-estar de animais silvestres cativos, o enriquecimento ambiental ainda é pouco utilizado para animais domésticos. A falta de desafios na vida doméstica de um animal tende a gerar distúrbios comportamentais. Estes distúrbios têm sido apontados como a maior causa de abandono de cães e gatos. Este trabalho teve como objetivo avaliar a promoção de bem-estar em cães de biotério e cães de Terapia Assistida por Animais (TAA), através de técnicas de enriquecimento ambiental, sendo avaliado o comportamento, a diversidade comportamental e as concentrações de cortisol sérico. Nos cães de biotério, foi possível observar diminuição de comportamentos de ansiedade e vocalização. Já nos cães de TAA, houve diminuição dos comportamentos de atenção e aumento dos comportamentos de brincadeira. Houve diferença significativa da diversidade comportamental somente no grupo dos cães de biotério e os mesmos também obtiveram diminuição significativa nas concentrações de cortisol. Não foi detectada correlação entre a diversidade comportamental e as concentrações de cortisol. O enriquecimento ambiental mostrou-se uma técnica eficaz para promover o bem-estar de cães mantidos em biotérios, mas não se mostrou tão eficaz em cães de TAA mantidos em canil, fazendo-se necessário a investigação de técnicas diferentes para este grupo de cães de trabalho. / Environmental enrichment is used to modify the physical or social environment of animals kept in captivity. Used since the 1970s to promote the welfare of captive wild animals, environmental enrichment is still little bit used for domestic animals. The lack of challenges in the domestic life of an animal tends to generate behavioral disorders. These disorders have been pointed out as a major cause of abandonment of dogs and cats. The objective of this work was to promote well-being in lab dogs and dogs of Animal-Assisted Therapy (AAT), through environmental enrichment techniques. Behavior, behavioral diversity and serum cortisol concentrations were evaluated. In the lab dogs, it was possible to observe the reduction of anxiety and vocalization behaviors. In AAT dogs, there was a decrease in attention behaviors and an increase in play behavior. There was a significant difference in the behavioral diversity only in the group of the lab dogs and they also obtained a significant decrease in cortisol concentrations. There was no correlation between a behavioral diversity and cortisol concentrations. Environmental enrichment has proved to be an effective technique to promote the welfare of dogs kept in labs, but it has not been shown to be effective in work dogs from AAT kept in kennels, thus making it necessary to investigate different techniques for this group.

abstract: The hypothalamus pituitary adrenal (HPA) axis and the human genome are important components of the biological etiology of externalizing disorders. By studying the associations between specific genetic variants, diurnal cortisol, and externalizing symptoms we can begin to unpack this complex etiology. It was hypothesized that genetic variants from the corticotropine releasing hormone receptor 1 (CRHR1), FK506 binding protein 51 (FKBP5), catechol-O-methyl transferase (COMT), and dopamine transporter (DAT1) genes and diurnal cortisol intercepts and slopes would separately predict externalizing symptoms. It was also hypothesized that genetic variants would moderate the association between cortisol and externalizing. Participants were 800 twins (51% boys), 88.5% Caucasian, M=7.93 years (SD=0.87) participating in the Wisconsin Twin Project. Hierarchical Linear Modeling (HLM) was used to separate the variance associated with state and trait cortisol measured across three consecutive days and trait cortisol measures were used. There were no main effects of genes on externalizing symptoms. The evening cortisol intercept, the morning cortisol slope and the evening cortisol slope predicted externalizing, but only in boys, such that boys with higher cortisol and flatter slopes across the day also had more externalizing symptoms. The morning cortisol intercept and CRHR1 rs242924 interacted to predict externalizing in both boys and girls, with GG carriers significantly higher compared to TT carriers at one standard deviation below the mean of morning cortisol. For boys only there was a significant interaction between the DAT1 variable number tandem repeat (VNTR) and the afternoon slope and a significant slope for 9/9 carriers and 9/10 carriers such that when the slope was more steep, boys carrying a nine had fewer externalizing symptoms but when the slope was less steep, they had more. Results confirm a link between diurnal trait cortisol and externalizing in boys, as well as moderation of that association by genetic polymorphisms. This is the first study to empirically examine this association and should encourage further research on the biological etiology of externalizing disorder symptoms. / Dissertation/Thesis / M.A. Psychology 2012

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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

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Fish experiencing stressful conditions increase production of the glucocorticoid hormone cortisol, which alters energy intake and allocation to help recover physiological homeostasis. Fish experiencing prolonged elevations of cortisol, however, often exhibit reduced somatic growth. While it has been shown previously in fish that cortisol inhibits anabolic growth processes in part via changes in endocrine growth hormone (Gh)/insulin- like growth factor-1 (Igf1) signaling, it is not fully understood which components of Gh/Igf1 pathways are modulated by cortisol. Here, we explored how cortisol influences the Gh/Igf1 system in blue rockfish (Sebastes mystinus) by administering exogenous cortisol and examining effects on Igf1 pathways. Cortisol-treated rockfish had higher plasma cortisol both 5 h and 24 h after injection compared to fish treated with vehicle solution only. Cortisol-treated rockfish also had lower plasma Igf1, even though relative expression of igf1 mRNAs in the liver was unaffected by cortisol. Rockfish treated with cortisol did, however, exhibit higher liver mRNA levels of Igf binding proteins (Igfbps) igfbp1a and igfbp1b, which encode Igfbps with proposed inhibitory influences on Igf1 stimulation of somatic growth. Cortisol-treated fish also expressed reduced liver mRNA levels of igfbp2a, an Igfbp thought to facilitate Igf1 transport in fish, as well as reduced mRNAs in skeletal muscle for myoblast determination protein 2 (myod2), a transcriptional activator for other genes promoting myocyte differentiation during myogenesis. Taken together, these findings point to cortisol-related changes in liver Igfbp expression as a mechanism for shifting Igf1 regulation of growth in fish experiencing elevated glucocorticoid secretion. Temperature is a key regulator of metabolism and growth in teleost fishes. Fish experiencing atypically high temperatures undergo a variety of physiological changes to cope with the elevated temperature, which often includes a reduction in the rate of somatic growth. Studies examining the effects of elevated temperatures on fish growth have typically focused on longer duration increases in average temperature. However, with anomalous ‘heat wave’ events becoming more common in aquatic habitats with climate change, fishes may increasingly be exposed to shorter-term periods of extreme elevated temperature. In this study, black rockfish (Sebastes melanops) were exposed to a short-duration period of elevated temperatures resembling the effects of a heat wave event on a rocky intertidal tidepool, a habitat used by young-of-the-year juveniles of this rockfish species. Black rockfish maintained on two different food rations (1% or 9% g feed per g body mass per day) for 21 d were exposed to elevated temperatures simulating a ~6°C maximum temperature increase for a ~54 h period, after which temperatures were returned to ambient ocean conditions. Rockfish in both ration treatments showed reduced body condition and lower mass-specific growth rates (SGR) during the 3 week period following the heat event period, but then subsequently increased growth above pre- stressor growth rates during the 6 and 9 week period after the high temperature event. Plasma insulin-like growth factor 1 (Igf1) hormone concentrations were correlated with an individual rockfish’s mass-specific growth rate prior to the heating event, but then decreased in both feed treatments following the event and no longer showed that positive relationship to growth. Plasma glucose was also altered by the heating event and increased to remain higher in both feed treatments following the heat event. Plasma osmolality was initially lower in both food ration groups 20 d after the heating event, but then diverged to increase back toward pre-event osmolality values in 9% ration fish, but not 1% ration fish, 6 weeks following the heat event. These findings suggest that exposure of juvenile black rockfish to an acute temperature elevation resembling the heat wave conditions that occur in the species’ tidepool nursey habitats may have consequences for both somatic growth and osmotic balance for weeks following the heating event.