Natural and Experimental Evidence Drives Marmosets for Research on Psychiatric Disorders Related to Stress

Knowledge of the behavioral ecology of marmosets carried out in their natural habitat associated with the advent of a non-invasive technique for measuring steroid hormones in feces has made a significant contribution to understanding their social relationships and sexual strategies. These studies showed that they are mainly monogamous, live in relatively stable social groups according to a social hierarchy in which females compete and males cooperate, and form social bonds similar to humans, which makes this species a potential animal model to study disorders related to social stress. In addition, laboratory studies observed the expression of behaviors similar to those in nature and deepened the descriptions of their social and reproductive strategies. They also characterized their responses to the challenge using behavioral, cognitive, physiological, and genetic approaches that were sexually dimorphic and influenced by age and social context. These findings, added to some advantages which indicate good adaptation to captivity and the benefits of the birth of twins, small size, and life cycle in comparison to primates of the Old World, led to their use as animal models for validating psychiatric diseases such as major depression. Juvenile marmosets have recently been used to develop a depression model and to test a psychedelic brew called Ayahuasca from the Amazon rainforest as an alternative treatment for major depression, for which positive results have been found which encourage further studies in adolescents. Therefore, we will review the experimental evidence obtained so far and discuss the extension of the marmoset as an animal model for depression

Hormonal changes related to paternal and alloparental care in common marmosets (Callithrix jacchus)

The physiological mechanisms of parental and alloparental care in cooperatively breeding nonhuman primate species such as the common marmoset (Callithrix jacchus) are poorly known. In this study, we examined prolactin and cortisol plasma levels of fathers and older offspring of both sexes, with and without previous experience in infant carrying, around parturition and during infant carrying. Blood samples were collected from fathers and older offspring and prolactin and cortisol were measured by RIA and EIA, respectively. Prolactin levels of both caretakers were not influenced by infant’s birth, previous experience or proximity to parturition. However, prolactin levels increased in both caretakers while in physical contact with infants and also with the number of infants being carried in older offspring. These findings suggest that increased prolactin seems to be mainly due to physical effort rather than a physiological trigger of paternal and alloparental care in common marmosets. Cortisol levels were higher for experienced fathers shortly before parturition which could act to reinforce affiliative bonds between breeding males and females at this time or in the ability of males to detect the proximity of the parturition or bot

New developmental stages for common marmosets (Callithrix jacchus) using mass and age variables obtained by K-means algorithm and self-organizing maps (SOM)

LEÃO, Adriano de Castro; DÓRIA NETO, Adrião Duarte; SOUSA, Maria Bernardete Cordeiro de. New developmental stages for common marmosets (Callithrix jacchus) using mass and age variables obtained by K-means algorithm and self-organizing maps (SOM). Computers in Biology and Medicine, v. 39, p. 853-859, 2009This study proposes new developmental stages for Callithrix jacchus, usingK-Means algorithm and an artificial neural network–self-organising maps (SOM) as computational tools, based on weight and age. Eight developmental stages are proposed: infantI ,IIandIII ,Juvenile I and II ,Subadult ,Young adult and Older adult. This classification is consistent with the first appearance of several behavioural and physiological characteristics and thus may have generality indefining critical developmental periods. It also reveals differences in male and female development and establishes stage for the onset of the final adult life cycle. This classification is also important to understanding the biology of the ontogenetic development of common marmosets, providing new insights for the management and care of captive animals and improving age estimate indicators when specimens are captured in long term monitoring of free ranging group

Circadian variation with a diurnal bimodal profile on scent-marking behavior in captive common marmosets (callitrhix jacchus)

Scent-marking behavior is associated with different behavioral contexts in callitrichids, including signalizing a territory, location of feeding resources, and social rank. In marmosets and tamarins it is also associated with intersexual communication. Though it appears very important for the daily routine of the individuals, very few researchers have investigated distribution through the 24-h cycle. In a preliminary report, we described a preferential incidence of this behavior 2 h before nocturnal rest in families of common marmosets. We expand the data using 8 family groups (28 subjects), 8 fathers, 6 mothers, 8 nonreproductive adults (4 sons and 4 daughters), and 6 juvenile (3 sons and 3 daughters) offspring that we kept in outdoor cages under natural environmental conditions. We recorded the frequency of anogenital scent marking for each group during the light phase, twice a wk, for 4 consecutive wks, from March 1998 to September 1999. Cosinor test detected 24- and 8-h variations in 89.3% and 85.7% of the subjects, respectively, regardless of sex or reproductive status. The 8-h component is a consequence of the 2 peaks for the behavior, at the beginning and end of the light phase. Daily distribution of scent marking is similar to that others described previously for motor activity in marmosets. The coincident rhythmical patterns for both behaviors seem to be associated with feeding behavior, as described for callitrichids in free-ranging conditions, involving an increase in foraging activities early in the morning and shortly before nocturnal res

Início da função gonadal no sagui comum (Callithrix jacchus): diferenças entre gêneros

Os primatas não humanos, como Callithrix jacchus vêm sendo utilizados com maior frequência em pesquisa biomédica e, recentemente, nosso laboratório propôs uma nova classificação para monitorar com mais detalhes as modificações comportamentais e hormonais relacionadas ao desenvolvimento. O presente trabalho monitorou os níveis de hormônios gonadais de 4 machos e 6 fêmeas de C. jacchus durante as fases juvenil I e II e subadulta (dos 5 aos 15 meses). Os resultados apontaram que os níveis de progesterona nas fêmeas e andrógenas nos machos foram estatisticamente mais elevados nos estágios juvenil II e subadulto, respectivamente, em relação ao estágio juvenil I. Estes achados indicam que, de acordo com a nova classificação, foi possível observar que o funcionamento gonadal se instala mais cedo nas fêmea

Impacto do apoio social sobre os sintomas de mulheres brasileiras com fibromialgia

ResumoObjetivou‐se avaliar o impacto do apoio social sobre os sintomas de mulheres brasileiras com fibromialgia (FM). Trata‐se de um estudo observacional descritivo que selecionou 66 mulheres que atendiam aos critérios do Colégio Americano de Reumatologia (ACR) de 1990. O apoio social foi medido com o Social Support Survey (MOS‐SSS), a funcionalidade com o Questionário do Impacto da Fibromialgia (FIQ), a depressão com o Inventário de Depressão de Beck (BDI), a ansiedade com a Escala de Ansiedade de Hamilton (HAS), a afetividade com o Positive and Negative Affect Schedule (Panas) e foi feita algometria para registrar o limiar da dor à pressão (LDP) e a tolerância álgica à pressão (TAP) nos 18 pontos recomendados pelo ACR. Os pacientes foram divididos nos grupos apoio social normal (ASN) ou ruim (ASR); o ASR foi definido como uma pontuação nos MOS‐SSS abaixo do percentil 25da amostra total. Usou‐se o teste de Mann‐Whitney ou o teste t não pareado para comparar variáveis intergrupos e o de Fisher para as variáveis categóricas. Usaram‐se a análise de covariância e o teste de correlação de Pearson. Não houve diferença nas variáveis sociodemográficas entre os grupos ASN e ASR. Observaram‐se diferenças entre os grupos ASN e ASR para todas as quatro subcategorias de apoio social e pontuação total do MOS‐SSS. Encontraram‐se diferenças significativas entre o ASN e o ASR na depressão (p=0,007), afeto negativo (p=0,025) e LDP (p=0,016). A subcategoria apoio afetivo mostrou correlação positiva entre a dor e o afeto positivo no grupo ASR. A subcategoria interação social positiva mostrou uma correlação negativa entre o FIQ e o estado de depressão. Portanto, o apoio social parece contribuir para a melhoria na saúde mental e física na FM.AbstractWe aimed to assess the impact of social support on symptoms in Brazilian women with FM. An observational, descriptive study enrolling sixty‐six women who met the 1990 American College of Rheumatology (ACR) criteria. Social support was measured by the Social Support Survey (MOS‐SSS), functionality was evaluated using the Fibromyalgia Impact Questionnaire (FIQ), depression was assessed using the Beck Depression Inventory (BDI), anxiety was measured using the Hamilton Anxiety Scale (HAS), affectivity was measured by Positive and Negative Affect Schedule (PANAS), and algometry was carried out to record pressure pain threshold (PPth) and tolerance (PPTo) at eighteen points recommended by the ACR. Patients were divided into normal (NSS) or poor social support (PSS) groups with PSS defined as having a MOS‐SSS score below the 25th percentile of the entire sample. Mann‐Whitney or Unpaired t‐test were used to compare intergroup variables and Fisher's for categorical variables. Analysis of covariance and Pearson correlation test were used. No differences in sociodemographic variables between PSS and NSS were found. Differences between NSS and PSS groups were observed for all 4 subcategories of social support and MOS‐SSS total score. Significant differences between NSS and PSS on depression (p= 0.007), negative affect (p= 0.025) and PPTh (p= 0.016) were found. Affectionate subcategory showed positive correlation between pain and positive affect in PSS. Positive social interaction subcategory showed a negative correlation between FIQ and depression state. Therefore social support appears to contribute to ameliorate mental and physical health in FM

Variação temporal diurna de comportamentos afiliativos de sagüi comum (Callithrix jacchus) machos vivendo em ambiente natural

O objetivo do presente estudo foi avaliar a variação temporal do comportamento afiliativo de machos reprodutores e não reprodutores de sagüi comum adultos, direcionados às fêmeas reprodutoras, vivendo em dois grupos naturais (GC1 e GR2). Os grupos habitavam uma área da Escola Agrícola de Jundiaí/UFRN, localizada em Macaíba, RN, Brasil. Para a coleta de dados foi utilizado o método focal instantâneo a cada 5 minutos, totalizando 11.563 registros. A análise estatística foi realizada utilizando testes não-paramétricos considerando p < 0,05. A freqüência de comportamentos afiliativos mostrou uma variação diurna, corroborando dados anteriores sobre a distribuição dos comportamento de contato, proximidade e catação social, indicando um perfil semelhante na expressão destas atividades para todos os indivíduos do grupo social

Variação na contagem de leucócitos em Callithrix jacchus (Linnaeus, 1758) submetidos a uma situação de estresse agudo

The hematological profile of common marmosets, Callithrix jacchus (L., 1758), is similar to that of humans and it is very important in comparative physiopathological studies. It is also known that stressful situations trigger immunologic responses, modifying peripheral leukocyte levels. In this study we evaluated if any quantitative change occurs in leukocytes whena co-specific same-sex intruder was introduced into the living cage of common marmosets (residents). Nineteen captive animals, ten females and nine males, were used. Blood samples were collected from the resident animal before (basal), during (stress) and after (recovery) intruderexposure. A significant increase in global (absolute and relative) neutrophil counting and a decrease in the percentage of lymphocytes during the recovery phase in both males and females were observed. These findings may represent a redistribution of the neutrophil reserve to the peripheral circulation to provide an adequate physiological response toacute stress in potencial injury situations in common marmosets

Modulação pela progesterona da sensibilidade dolorosa a estímulos mecânicos e isquêmicos em mulheres saudáveis e jovens Modulation by progesterone of pain sensitivity to mechanical and ischemic stimuli in young and healthy women

OBJETIVO: investigar a relação entre percepção da dor (limiar e tolerância à dor experimental em resposta à isquemia e à pressão) em mulheres jovens e saudáveis com os níveis séricos dos hormônios sexuais femininos (estradiol e progesterona). MÉTODOS: 18 voluntárias participaram deste estudo durante três ciclos menstruais consecutivos. Para mensuração das respostas dolorosas aos estímulos algésicos de pressão e isquemia, utilizaram-se um algômetro de pressão e dinamômetro manual, respectivamente. Foram realizadas coletas de sangue para dosagem hormonal e de variáveis dolorosas durante três ciclos menstruais consecutivos, os quais foram caracterizados com base no registro da temperatura oral diária, diário dos ciclos menstruais contendo início e fim de cada ciclo e nos níveis plasmáticos de estradiol e progesterona. As médias aferidas para as variáveis algésicas foram comparadas pela análise de variância (ANOVA) com pós-teste de Tukey-Kramer entre as fases do ciclo menstrual (folicular, periovulatória, luteal inicial, luteal tardia e menstrual). Para o estudo da correlação entre as variáveis algésicas e hormonais, utilizou-se o teste de Pearson. A significância estatística foi definida pelo limite pPURPOSE: to investigate the relationship between pain perception (experimental pain threshold and tolerance, in response to ischemia and pressure) in young and healthy young women and female sexual hormone seric levels (estradiol and progesterone). METHODS: 18 volunteers have participated of this study, during three consecutive menstrual cycles. A pressure algometer and a manual dynamometer have been used to measure painful responses to pressure and ischemia algesic stimuli. Blood has been collected for assessment of both hormonal and painful variables, during three menstrual cycles, whose characterization was based on daily oral temperature record, a diary of the menstrual cycles with the onset and end of each cycle, and on estradiol and progesterone plasmatic levels. The average for the algesic variables measured has been compared by analysis of variance (ANOVA) and the Tukey-Kramer's post-test, among the menstrual cycle phases (follicular, periovulatory, early luteal, late luteal and menstrual). The Pearson's test has been used for correlation analysis between algesic and hormonal variables. Statistical significance has been defined as p<0.05. RESULTS: no significant change in pain parameters among the menstrual cycle phases has been observed. Nevertheless, there have been significant negative correlations between progesterone and ischemic threshold (r=-0.23; p<0.01), and pressure tolerance (r=-0.23; p<0.01) at the early luteal phase. CONCLUSIONS: these results indicate that the increase in progesterone levels correlates with a decrease of ischemic threshold and pressure tolerance, suggesting that progesterone plays a role in the pain modulation during the early luteal phase