Despite recent research advances, there are still several common medical conditions whose underlying mechanisms are poorly understood. In conditions with few or diffuse physical findings, it can be difficult to diagnose and determine the state of the condition and its effects on working ability or performance, and the health care practitioners have to rely on the patient’s self-reports. Identification of objective measurements that are sensitive enough to aid in diagnosis or determination of the state of these conditions would thus be valuable. Psychophysiological measurements are generally non-invasive and have the potential to serve as such diagnostic or prognostic tools. In this thesis, psychophysiological reactions to different stressors were recorded in two selected medical conditions; namely motion sickness and chronic trapezius myalgia (musculoskeletal pain). These subjective conditions are unpleasant, unwanted and apparently serve no survival purpose. It is therefore important to elucidate any physical findings associated with them to, eventually, find new means to prevent the development of these conditions or to ameliorate symptoms. The overall aim of the thesis was to explore the development of psychophysiological responses to stressors in relation to performance and subjective reports in healthy individuals and in women with chronic trapezius myalgia. More in detail, the purpose was to identify psychophysiological responses that could provide information about the mechanisms behind, or serve as candidates for characterization of motion sickness and chronic trapezius myalgia, respectively. Responses to motion sickness, triggered by optokinetic stimulation, were studied in healthy individuals, whereas responses to repetitive low-force work and psychosocial stress were studied in women with chronic trapezius myalgia and in pain-free controls. In both medical conditions, the psychophysiological responses were accompanied by subjective reports. The effects of motion sickness on two different aspects of memory performance were tested during exposure to optokinetic stimulation. In the studies of chronic trapezius myalgia, psychophysiological responses were also related to health status, i.e., being a patient or a pain-free control and measurements of pain intensity, psychological symptoms, sleep-related problems and quality of life. The psychophysiological responses to optokinetic stimulation were inconclusive. Moderate levels of motion sickness did not affect memory performance, whereas decreased short term memory performance was seen in subjects reporting high levels of motion sickness. The autonomic responses and stress hormone secretion in response to low-force repetitive work and psychosocial stress in the chronic trapezius myalgia group were similar to those of the pain-free controls. However, muscle activity in the trapezius muscle was generally higher in the chronic trapezius myalgia group. There were indications of negative psychological states being related to a slower response and lower circadian variations of stress hormone secretion. With the present methods, it was possible to measure general stress responses but none of the measurements showed sufficient specificity to serve as predictors or indicators of motion sickness and chronic musculoskeletal pain, respectively. Summarizing, I cannot objectively measure how you feel; I still have to rely on your description of your condition.

The affective disorders (anxiety and depression) are common psychiatric disorders that primarily involve disturbances in mood and represent the second leading source of disease burden world-wide. A wide base of evidence supports a significant genetic contribution to these disorders. Polymorphic variation in the promoter region (5-HTTLPR) of the human serotonin transporter (hSERT) gene, which leads to a life-long alteration in serotonin transporter (SERT) expression and functioning, has been implicated in the aetiology of both anxiety and depression. Despite the strong evidence implicating a role for this polymorphism in affective psychopathology the underlying mechanism by which genetically determined SERT bioavailability influences affective functioning are not understood. In these studies I attempt to elucidate the alterations in cerebral, serotonin (5-HT) system and hypothalamo-pituitary-adrenal (HPA) axis functioning which may relate to the effect of the 5-HTTLPR on affective functioning by characterising these parameters in an animal model of genetically increased SERT expression (hSERT over-expressing mice; hSERT OVR). Furthermore, as gender influences both the likelihood of developing affective disorders and the impact of the 5-HTTLPR on affective functioning, with a greater effect being observed in females than in males, we characterise these parameters in mice of both genders. The data presented in this thesis demonstrate that the life-long increase in SERT bioavailability present in hSERT OVR mice produces profound alterations in cerebral, serotonin system and HPA axis functioning. Furthermore, the influence of increased SERT expression upon cerebral and serotonin system functioning is greater in females than in males. Additionally, a number of sexually dimorphic variations in serotonin system functioning were identified. Thus this thesis extends the currently available information regarding the underlying mechanisms by which gender and a life-long alteration in SERT expression may influence the risk of affective psychopathology.

Opiate addiction is now a major public health problem. Pregnant women continue to use opiates during gestation; up to 5.4% of pregnant women report using illicit drugs during pregnancy. Previous studies have shown that perinatal insults and exposure to opiates such as morphine in utero can affect the development of the hypothalamic-pituitary-adrenal (HPA)-axis of the offspring and are associated with higher risk of developing neurobehavioral problems. Oxycodone, a semisynthetic putative kappa opioid receptor and partial mu opioid receptor agonist is now one of the most frequently abused pain killers during pregnancy, however limited data are available regarding whether and how perinatal oxycodone exposure (POE) alters the development and functions of the HPA-axis, the related stress axis and neurobehavioral outcomes of the offspring. Data from these experiments have provided novel evidence that POE indeed is associated with sex-specific changes in the HPA-axis in response to stress that persist beyond the neonatal period. 1) POE is associated with an increased adrenocorticotropic hormone (ACTH) response to corticotropin-releasing hormone (CRH), but not the corticosterone (CORT) response to CRH stimulation in late adolescent male offspring. 2) POE is associated with increased CORT, but not ACTH response to restraint stress test in adult female offspring. These changes in the HPA-axis response to stress may be partially explained by 1) an increase in the subpopulation of CRH neurons that also contain estrogen receptor-beta immunoreactivity following POE which then can exaggerate the stimulation of the HPA-axis, and 2) a decrease in mineralocorticoid receptor-mRNA expression in the hippocampus which may be associated with impaired negative feedback control of the HPA-axis by the limbic system. POE is also associated with cardiovascular changes in response to stress during a classical conditioning paradigm; adolescent male POE rats have a larger blood pressure increase than the control group. Although POE male rats can properly discriminate the stress versus non-stress cues in the conditioning paradigm, they do not retain this memory when retested during adulthood. When tested for learning and memory in a water maze, however, we did not find any differences between control rats and rats exposed to high dose oxycodone in utero. In addition, we demonstrated that exposure to the lower dose of oxycodone in utero is associated with hyperactivity in adult rats when tested in an open field. Our results make a significant contribution to the literature because they extend our knowledge about the effects of oxycodone on the developing brain and the resulting outcomes in animal models that are actually relevant to a current major public health problem in humans and will provide a platform for us to further study the underlying mechanisms and interventions that may mitigate these effects.

INTRODUÇÃO: A exposição ao estresse precoce (EP) pode estar associada à depressão na vida adulta. Evidencias demonstram que alterações na capacidade regulatória do eixo hipotálamo-pituitária-adrenal (HPA) sejam subjacentes a essa associação. Pacientes depressivos com EP tendem a apresentar quadros clinicamente mais graves, com pior prognóstico e resposta limitada aos tratamentos usuais. Não se sabe ainda como é o perfil cognitivo desses pacientes e como as alterações na atividade do eixo HPA impactam no desempenho neuropsicológico. OBJETIVO: O objetivo deste trabalho foi investigar a atividade do eixo HPA, através dos níveis de cortisol basal, e as funções cognitivas em pacientes depressivos com história de estresse precoce. METODO: Integrou a amostra total do estudo 107 sujeitos, sendo 77 pacientes depressivos e 30 sujeitos saudáveis com idade entre 21 e 60 anos de ambos os sexos. Foram incluídos pacientes com diagnóstico confirmado de episódio depressivo maior e gravidade de sintomas pelo menos moderada no momento das avaliações. O Questionário de Traumas na Infância (CTQ) avaliou a história de EP dividindo a amostra de pacientes em dois grupos, um com estresse precoce (EP+) e outro sem estresse precoce (EP-). Os participantes foram avaliados quanto a gravidade de sintomas psiquiátricos relacionados ao quadro depressivo, quanto à impulsividade e ao temperamento afetivo. A avaliação neuropsicológica incluiu testes de memória verbal, memória visuoespacial, memória de trabalho, atenção sustentada e dividida, além de medidas de controle inibitório, flexibilidade cognitiva, fluência verbal e QI. Na avaliação endócrina cinco amostras de cortisol salivar e de uma amostra de cortisol plasmático foram analisadas para a avaliação da atividade do eixo HPA. RESULTADOS: Setenta e dois por cento dos pacientes depressivos apresentaram EP. A história de EP influenciou o início mais precoce dos quadros depressivos (p=0,03). Não foram encontradas diferenças entre os grupos de pacientes na gravidade de sintomas psiquiátricos, comorbidades clínicas. Não encontramos diferenças entre os pacientes EP+ e EP- comparados a controles no temperamento hipertímico. Na avaliação da atividade do eixo HPA, o grupo EP+ apresentou perda do ritmo circadiano (RC) de cortisol em relação ao grupo controle, além de aumento dos níveis de cortisol salivar às 22h em comparação ao grupo EP- (p=0,04) e uma tendência comparado ao grupo controle (p=0,06). No desempenho neuropsicológico, os pacientes EP+ apresentaram prejuízos em relação aos controles em todos os subdomínios cognitivos avaliados (p<0,05 para todos os escores), exceto memória visuoespacial (p=0,13). Em contraste, os pacientes EP- mostraram déficits apenas em memória de trabalho (p=0,006), alternância atencional (p=0,01) e controle inibitório (p=0,004) comparados aos controles. Na comparação entre os grupos de pacientes, os EP+ apresentaram déficit na nomeação de cores (p=0,01) e uma tendência de prejuízo na memória verbal tardia (p=0,07). Entre os pacientes EP+ encontramos correlações moderadas entre a diminuição da variabilidade nos níveis de cortisol salivar no RC com os prejuízos na flexibilidade cognitiva (?=0,61; p=0,002) e com o controle inibitório (?=0,42; p=0,048). CONCLUSÃO: Nossos achados apontam para um perfil endócrino e neuropsicológico distinto nos pacientes EP+ em comparação com pacientes com depressão EP- e controles. A combinação da história de EP à depressão resultou em inicio mais precoce da doença, prejuízos cognitivos abrangentes e perda na manutenção do ritmo circadiano de cortisol. / BACKGROUND: Exposure to early-life stress (ELS) may be associated with depression in adulthood. Evidence shows that changes in the regulatory capacity of the hypothalamicpituitary-adrenal axis (HPA) underlie association. Patients with ELS usually are more clinically ill, showing poorer prognosis and limited response to usual treatments. It is not known yet what the cognitive profile of those patients is and how changes in the HPA axis activity would impact on cognitive functioning. AIM: The aim of this study was to investigate the HPA axis activity through basal cortisol levels and cognitive functions mediated by the hippocampus and the prefrontal cortex in depressed patients with early stress history. METHOD: Study total study sample was 107 subjects, 77 depressed patients and 30 healthy subjects aged between 21 and 60 years of both sexes. Patients had diagnosis confirmed for major depressive episode with symptom severity at least moderate by the time of the evaluations. We used the Childhood Trauma Questionnaire (CTQ) to assess the ELS history splitting the patient sample into two groups, one with early life stress (ELS+) and the other without early stress (ELS-). Participants were assessed for severity of psychiatric symptoms related to depression, such as impulsivity and affective temperament. The neuropsychological evaluation included tests for verbal memory, visuospatial memory, working memory, sustained and divided attention, inhibitory control measures, cognitive flexibility, verbal fluency, and IQ. For the endocrine assessment five samples of salivary cortisol and plasma cortisol were analyzed to evaluate HPA axis functioning. RESULTS Seventy-two percent of depressive patients had ELS. ELS itself influenced earlier onset of depressive disorders in patients (p = 0.03). Most of the affective temperaments are more prominent in patients with mood disorders than health controls. Regarding the assessment of the HPA axis activity, ELS + group showed lack of cortisol circadian rhythm (CR) compared to the control group. We also found increased salivary cortisol levels at 22 pm compared to the EP- group (p = 0.04) and a trend toward the control group (p = 0.06). In neuropsychological performance, patients EP + showed deficits compared to controls in all of the cognitive subdomains evaluated (p <0.05 for all test scores) except visuospatial memory (p = 0.13). In contrast, ELS-patients showed worse performance only in working memory (p = 0.006), attentional switching (p = 0.01) and inhibitory control (p = 0.004) compared to controls. Comparisons between patient groups showed that EP + patients had a deficit in color naming (p = 0.01) and a trend toward delayed verbal memory (p = 0.07). We found moderate positive correlations for EP+ patients between decreased variation in salivary cortisol levels in the CR and impairments in cognitive flexibility (? = 0.61; p = 0.002) and also to inhibitory control ( ? = 0.42, p = 0.048). CONCLUSION: Our findings indicate a distinct endocrine and neuropsychological profile in patients ELS + compared to depressed EP-. The combination of ELS history and depression resulted in early onset of the depression symptoms, comprehensive cognitive impairment in tasks related to the CPF and hippocampus, and failure in maintaining the circadian rhythm of cortisol.

A ouabaína (OUA), um inibidor da Na+ ,K+-ATPase, foi identificada como uma substância endógena presente no plasma humano, e parece estar envolvida na resposta ao estresse agudo, em animais e seres humanos. O estresse crônico é um importante fator agravante de doenças psiquiátricas, incluindo depressão e ansiedade. Além disso, problemas cognitivos são cada vez mais reconhecidos como importantes componentes da ansiedade e depressão. Diante disto, o presente trabalho buscou investigar os efeitos da OUA (1,8 <font face = \"symbol\">mg/kg) na hiperatividade do eixo HPA, na neuroinflamação, na expressão de receptores e proteínas envolvidos na plasticidade sináptica, nos efeitos comportamentais (como déficit de memória de longa duração, depressão e ansiedade) e atividade da Na+,K+-ATPase induzidos pelo protocolo de estresse crônico imprevisível (CUS) realizado ao longo de 14 dias em ratos. Nossos resultados demonstraram que o tratamento intermitente com OUA é capaz de reverter a hiperatividade do eixo HPA induzido pelo CUS, por meio da redução de glicocorticoide, redução na expressão de CRH-CRHR1, bem como diminuir a neuroinflamação, e aumentar os níveis de BDNF e fazer o que na expressão dos receptores CRHR2. Essas alterações bioquímicas contribuíram para uma reversão nos prejuízos na memória de longo prazo induzida pelo CUS. Ademais os animais tratados apenas com OUA, bem como os submetidos ao CUS e tratados com OUA obtiveram uma melhora na memória emocional, averiguada no teste comportamental de condicionamento da memória ao medo. Os resultados encontrados sugerem que o protocolo de CUS por 14 dias promove uma adaptação neuronal facilitando a redesignação da memória ao medo, aqui configurado pelo choque, e o tratamento com a OUA abrevia esse processo. Em conclusão os nossos resultados sugerem que o tratamento intermitente com OUA suscita uma adaptação no eixo HPA, por meio de alterações na expressão dos receptores para CRH no hipocampo e hipotálamo, resultando em uma adaptação na memória emocional relacionada ao medo. / Ouabain (OUA), an inhibitor of Na+, K+ -ATPase, has been identified as an endogenous substance present in human plasma, and appears to be involved in the response to acute stress in animals and humans. Chronic stress is an important aggravating factor of psychiatric illness, including depression and anxiety. In addition, cognitive problems are increasingly recognized as important components of anxiety and depression. The present work aimed to investigate the effects of OUA (1.8 <font face = \"symbol\">mg/kg) on HPA axis hyperactivity, neuroinflammation, expression of receptors and proteins involved in synaptic plasticity, behavioral effects (such as long-term memory deficit duration, depression and anxiety) and Na+,K+-ATPase activity induced by the unpredictable chronic stress protocol (CUS) performed over 14 days in rats. Our results demonstrated that intermittent treatment with OUA was able of reversing CUS-induced HPA axis hyperactivity, by reducing glucocorticoid levels, CRH-CRHR1 expression, as well as reducing CUS-induced low-grade neuroinflammation, and increase BDNF levels and expression of CRHR2 receptors. These biochemical changes contributed to a reversal in CUS-induced long-term memory impairment. In addition, animals treated only with OUA, as well as those submitted to CUS, and also treated with OUA obtained an improvement in emotional memory, which was explored in the fear conditioning test. These results suggest that the CUS protocol of 14 days promotes a neural adaptation facilitating a reassignment of the memory to the fear, here configured by the shock, and the treatment with the OUA shortens that process. In conclusion, our results suggest that intermittent treatment with OUA induces an adaptation on the HPA axis, through alterations in the expression of receptors for CRH in the hippocampus and hypothalamus, resulting in an adjustment in fear-related emotional memory.

Há evidencias de interação bidirecional dos eixos HPA e HPG envolvendo diferentes estruturas, entretanto, os mecanismos envolvidos são pouco compreendidos. Situações de estresse podem alterar a função reprodutiva, e hormônios gonadais podem modificar a resposta de estresse. O objetivo deste trabalho foi verificar se estrógeno (E 2) e progesterona (P4) modificam a atividade basal do eixo hipotálamo-hipófise-adrenal (HPA), analisada pelas secreções de corticosterona (CORT) e de P4 e pelas expressões de receptores para corticosteróides (mineralocorticóides, MR e glicocorticóides, GR) em sítios cerebrais de retroalimentação do eixo HPA. Ratas Wistar adultas foram mantidas em ciclo claro-escuro de 12h e acesso livre à ração e água. O ciclo estral foi monitorado por esfregaço vaginal e a determinação da secreção de hormônio luteinizante (LH) foi realizada para confirmação do proestro. Seis amostras de sangue foram coletadas através de cateter na jugular, durante a tarde (13-18h), dos seguintes grupos de ratas: ovariectomizadas (OVX); controles em proestro; tratadas com antagonista de E 2 (tamoxifen) ou de P4 (RU486), ou ambos; tratadas com os respectivos veículos dos antagonistas. O plasma foi separado e estocado para dosagens hormonais por radioimunoensaio. Após a última coleta de sangue, os animais foram anestesiados e perfundidos para remoção dos cérebros, que foram manipulados para verificação por imunofluorescência, da expressão de MR e de GR na região CA1 e no subículo do hipocampo ventral, e de GR no núcleo paraventricular (PVN). Os resultados mostram que: a secreção de LH confirmou a fase de proestro; a secreção basal de CORT não foi alterada pelas manipulações de injeções nem pela remoção dos ovários; ocorreu pico de secreção de CORT e de P 4 às 14h em todos os grupos experimentais; os antagonistas de E 2 e de P 4 não alteraram a secreção total de CORT, porém o RU486 aumentou (às 13 e 15h) e o tamoxifen reduziu (às 15h) a concentração de CORT; um segundo pico de secreção de P 4 no final da tarde (17-18h) foi bloqueado pela ovariectomia e por Tamoxifen , e amplificado por RU486; o segundo pico de P 4 também não ocorreu em ratas tratadas com Tamoxifen e RU486 ; não houve alteração do número de neurônios com expressão de GR e MR na região CA 1 e no subículo do hipocampo ventral nem de GR no PVN. Em conclusão, nossos resultados indicam que: E2 e P 4 podem exercer efeitos antagônicos sobre a secreção basal de CORT, respectivamente estimulatório e inibitório; os picos de secreção de P 4 têm origens diferentes, o primeiro (14h) da adrenal e o segundo (17-18h) do ovário; E 2 estimula a secreção ovariana de P 4 na tarde de proestro; E2 e P 4 não alteram o número de neurônios que expressam GR e MR em sítios de retroalimentação do eixo HPA, mas não se pode descartar que alterem a atividade desses neurônios. / There is evidence for a bidirectional communication between HPA and HPG axis involving different structures, however the involved mechanisms are poorly known. Stress situations may alter the reproductive function, and gonadal steroids may modify the stress response. The aim of this study was verify if estrogen (E 2) and progesterone (P 4 ) can alter the basal activity of hypothalamic-pituitary-adrenal axis, analyzed by corticosterone (CORT) and P 4 secretions and by mineralocorticoid and glicocorticoid receptors (MR and GR, respectively) expression at HPA axis central feedback sites. Adult female Wistar rats were kept in 12h light-dark cycle and had free access to food and water. The estrous cycle was monitored by vaginal smears and the luteinizing hormone dosage was done to confirm proestrus. Six samples of blood were collected by jugular cannula, during the afternoon (13-18h), of the following groups: ovariectomized (OVX), proestrus controls, treated with E 2 or P 4 antagonists (tamoxifen or RU486, respectively), or with both, and treated with antagonists vehicle. The plasm was stored for hormonal dosages by radioimmunoassay. After the last blood sample, animals were anesthetized, perfused, and the brains were removed and processed for immunofluorescence to analyze MR and GR expression at ventral hippocampus CA 1 and subiculum, and GR expression at paraventricular nucleus (PVN). The results showed that: LH secretion confirmed the proestrus; CORT basal secretion was not altered by injections neither by ovariectomy; there was a CORT and a P4 secretion peak at 14h in all experimental groups, E 2 and P 4 antagonists did not modify the CORT total secretion, however RU486 increased (at 13 and 15h) and tamoxifen reduced (at 15h) CORT levels, another P4 secretion peak in the late afternoon (17-18h) was blocked by ovariectomy and tamoxifen, but enhanced by RU486, the P 4 second peak did not occur in rats treated with both tamoxifen and RU486, there were no changes in the number of neurons expressing GR and MR at ventral hippocampus CA 1 and subiculum neither of GR expressing neurons at PVN. In conclusion, our results indicate that: E2 and P 4 can have antagonistic effects over basal CORT secretion; stimulatory and inhibitory, respectively; the P 4 secretion peaks have different origins, the first (14h) is adrenals and the second (17-18h) is ovarian: E2 stimulates ovarian P 4 secretion in the proestrus afternoon; E 2 and P 4 do not alter the number of neurons that express MR and GR at HPA axis feedback sites, but one can not exclude the possibility that they alter the activity of these neurons.

INTRODUÇÃO: A exposição ao estresse precoce (EP) pode estar associada à depressão na vida adulta. Evidencias demonstram que alterações na capacidade regulatória do eixo hipotálamo-pituitária-adrenal (HPA) sejam subjacentes a essa associação. Pacientes depressivos com EP tendem a apresentar quadros clinicamente mais graves, com pior prognóstico e resposta limitada aos tratamentos usuais. Não se sabe ainda como é o perfil cognitivo desses pacientes e como as alterações na atividade do eixo HPA impactam no desempenho neuropsicológico. OBJETIVO: O objetivo deste trabalho foi investigar a atividade do eixo HPA, através dos níveis de cortisol basal, e as funções cognitivas em pacientes depressivos com história de estresse precoce. METODO: Integrou a amostra total do estudo 107 sujeitos, sendo 77 pacientes depressivos e 30 sujeitos saudáveis com idade entre 21 e 60 anos de ambos os sexos. Foram incluídos pacientes com diagnóstico confirmado de episódio depressivo maior e gravidade de sintomas pelo menos moderada no momento das avaliações. O Questionário de Traumas na Infância (CTQ) avaliou a história de EP dividindo a amostra de pacientes em dois grupos, um com estresse precoce (EP+) e outro sem estresse precoce (EP-). Os participantes foram avaliados quanto a gravidade de sintomas psiquiátricos relacionados ao quadro depressivo, quanto à impulsividade e ao temperamento afetivo. A avaliação neuropsicológica incluiu testes de memória verbal, memória visuoespacial, memória de trabalho, atenção sustentada e dividida, além de medidas de controle inibitório, flexibilidade cognitiva, fluência verbal e QI. Na avaliação endócrina cinco amostras de cortisol salivar e de uma amostra de cortisol plasmático foram analisadas para a avaliação da atividade do eixo HPA. RESULTADOS: Setenta e dois por cento dos pacientes depressivos apresentaram EP. A história de EP influenciou o início mais precoce dos quadros depressivos (p=0,03). Não foram encontradas diferenças entre os grupos de pacientes na gravidade de sintomas psiquiátricos, comorbidades clínicas. Não encontramos diferenças entre os pacientes EP+ e EP- comparados a controles no temperamento hipertímico. Na avaliação da atividade do eixo HPA, o grupo EP+ apresentou perda do ritmo circadiano (RC) de cortisol em relação ao grupo controle, além de aumento dos níveis de cortisol salivar às 22h em comparação ao grupo EP- (p=0,04) e uma tendência comparado ao grupo controle (p=0,06). No desempenho neuropsicológico, os pacientes EP+ apresentaram prejuízos em relação aos controles em todos os subdomínios cognitivos avaliados (p<0,05 para todos os escores), exceto memória visuoespacial (p=0,13). Em contraste, os pacientes EP- mostraram déficits apenas em memória de trabalho (p=0,006), alternância atencional (p=0,01) e controle inibitório (p=0,004) comparados aos controles. Na comparação entre os grupos de pacientes, os EP+ apresentaram déficit na nomeação de cores (p=0,01) e uma tendência de prejuízo na memória verbal tardia (p=0,07). Entre os pacientes EP+ encontramos correlações moderadas entre a diminuição da variabilidade nos níveis de cortisol salivar no RC com os prejuízos na flexibilidade cognitiva (?=0,61; p=0,002) e com o controle inibitório (?=0,42; p=0,048). CONCLUSÃO: Nossos achados apontam para um perfil endócrino e neuropsicológico distinto nos pacientes EP+ em comparação com pacientes com depressão EP- e controles. A combinação da história de EP à depressão resultou em inicio mais precoce da doença, prejuízos cognitivos abrangentes e perda na manutenção do ritmo circadiano de cortisol. / BACKGROUND: Exposure to early-life stress (ELS) may be associated with depression in adulthood. Evidence shows that changes in the regulatory capacity of the hypothalamicpituitary-adrenal axis (HPA) underlie association. Patients with ELS usually are more clinically ill, showing poorer prognosis and limited response to usual treatments. It is not known yet what the cognitive profile of those patients is and how changes in the HPA axis activity would impact on cognitive functioning. AIM: The aim of this study was to investigate the HPA axis activity through basal cortisol levels and cognitive functions mediated by the hippocampus and the prefrontal cortex in depressed patients with early stress history. METHOD: Study total study sample was 107 subjects, 77 depressed patients and 30 healthy subjects aged between 21 and 60 years of both sexes. Patients had diagnosis confirmed for major depressive episode with symptom severity at least moderate by the time of the evaluations. We used the Childhood Trauma Questionnaire (CTQ) to assess the ELS history splitting the patient sample into two groups, one with early life stress (ELS+) and the other without early stress (ELS-). Participants were assessed for severity of psychiatric symptoms related to depression, such as impulsivity and affective temperament. The neuropsychological evaluation included tests for verbal memory, visuospatial memory, working memory, sustained and divided attention, inhibitory control measures, cognitive flexibility, verbal fluency, and IQ. For the endocrine assessment five samples of salivary cortisol and plasma cortisol were analyzed to evaluate HPA axis functioning. RESULTS Seventy-two percent of depressive patients had ELS. ELS itself influenced earlier onset of depressive disorders in patients (p = 0.03). Most of the affective temperaments are more prominent in patients with mood disorders than health controls. Regarding the assessment of the HPA axis activity, ELS + group showed lack of cortisol circadian rhythm (CR) compared to the control group. We also found increased salivary cortisol levels at 22 pm compared to the EP- group (p = 0.04) and a trend toward the control group (p = 0.06). In neuropsychological performance, patients EP + showed deficits compared to controls in all of the cognitive subdomains evaluated (p <0.05 for all test scores) except visuospatial memory (p = 0.13). In contrast, ELS-patients showed worse performance only in working memory (p = 0.006), attentional switching (p = 0.01) and inhibitory control (p = 0.004) compared to controls. Comparisons between patient groups showed that EP + patients had a deficit in color naming (p = 0.01) and a trend toward delayed verbal memory (p = 0.07). We found moderate positive correlations for EP+ patients between decreased variation in salivary cortisol levels in the CR and impairments in cognitive flexibility (? = 0.61; p = 0.002) and also to inhibitory control ( ? = 0.42, p = 0.048). CONCLUSION: Our findings indicate a distinct endocrine and neuropsychological profile in patients ELS + compared to depressed EP-. The combination of ELS history and depression resulted in early onset of the depression symptoms, comprehensive cognitive impairment in tasks related to the CPF and hippocampus, and failure in maintaining the circadian rhythm of cortisol.

The “Free Hormone Hypothesis” posits that only free, unbound hormone is biologically active and available to tissues. Conventional biomedical wisdom proposes that corticosteroid-binding globulin (CBG) normally binds 90-95% of blood glucocorticoid (GC), rendering it unavailable to tissues. Under chronic stress, GC levels greatly exceed binding capacity resulting in impaired bodily function and reduced fitness. However, under normal conditions in northern and southern flying squirrels, less than 10% of GC is bound, presenting a major challenge to the hypothesis. To assess the extent of variation in these properties among vertebrates, I compared all species (88) with known GC and CBG and levels. 92% conform reasonably to known convention. Flying squirrels appear as extreme species, as do New World monkeys, yet both groups evolved from ancestors that followed normal convention. I speculate as to how this state evolved and persisted through time.

The “Free Hormone Hypothesis” posits that only free, unbound hormone is biologically active and available to tissues. Conventional biomedical wisdom proposes that corticosteroid-binding globulin (CBG) normally binds 90-95% of blood glucocorticoid (GC), rendering it unavailable to tissues. Under chronic stress, GC levels greatly exceed binding capacity resulting in impaired bodily function and reduced fitness. However, under normal conditions in northern and southern flying squirrels, less than 10% of GC is bound, presenting a major challenge to the hypothesis. To assess the extent of variation in these properties among vertebrates, I compared all species (88) with known GC and CBG and levels. 92% conform reasonably to known convention. Flying squirrels appear as extreme species, as do New World monkeys, yet both groups evolved from ancestors that followed normal convention. I speculate as to how this state evolved and persisted through time.

Following social defeat, male hamsters exhibit behavioral changes characterized by a breakdown of normal territorial aggression and an increase in submissive/defensive behaviors in the presence of a non-aggressive intruder (NAI). We have termed this phenomenon conditioned defeat (CD). By contrast, only a small subset of defeated females exhibit submissive/defensive behavior in the presence of a NAI. We hypothesized that fluctuations in gonadal hormones might contribute to differences in the display of submissive behavior in intact female hamsters. Following social defeat, proestrous females (higher endogenous estradiol) were more likely to display conditioned defeat compared with diestrous 1 (lower endogenous estradiol) females. This finding suggests that there is an estrous cycle-dependent fluctuation in the display of CD in female hamsters and suggests that increased estradiol might contribute to increased submissive behavior. We then demonstrated that ovariectomized females given estradiol prior to CD testing exhibited significantly higher submissive behavior in the presence of a NAI suggesting that estradiol increases the expression of CD in female hamsters. We have also shown that castrated males that were singly housed for four weeks displayed significantly more submissive behavior than did their intact counterparts. Interestingly, castrated and intact males that were singly housed for 10 days prior to behavioral testing displayed similar behavior during CD testing. Together these data suggest that androgens and isolation modulate the display of CD in male hamsters. Finally, we examined brain activation following CD testing in defeated males and females (in diestrus 1 and proestrus). Defeated male and proestrous females exhibited increased Fos activation in the dorsal lateral septum and hypothalamic paraventricular nucleus relative to defeated diestrous 1 females. Diestrous 1 females exhibited increased Fos expression in the lateral bed nucleus of the stria terminalis compared with both defeated groups. Collectively, these data suggest that gonadal hormones and duration of individual housing modulate the display of CD in female and male hamsters and that those animals which display CD exhibit differences in patterns of neuronal activation than do those that do not display CD.