Behavioral effects of endogenous or exogenous estradiol and progesterone on cocaine sensitization in female rats

Cocaine sensitization is a marker for some facets of addiction, is greater in female rats, and may be influenced by their sex hormones. We compared the modulatory effects of endogenous or exogenous estradiol and progesterone on cocaine-induced behavioral sensitization in 106 female rats. Ovariectomized female rats received progesterone (0.5 mg/mL), estradiol (0.05 mg/mL), progesterone plus estradiol, or the oil vehicle. Sham-operated control females received oil. Control and acute subgroups received injections of saline, while the repeated group received cocaine (15 mg/kg, ip) for 8 days. After 10 days, the acute and repeated groups received a challenge dose of cocaine, after which locomotion and stereotypy were monitored. The estrous cycle phase was evaluated and blood was collected to verify hormone levels. Repeated cocaine treatment induced overall behavioral sensitization in female rats, with increased locomotion and stereotypies. In detailed analysis, ovariectomized rats showed no locomotor sensitization; however, the sensitization of stereotypies was maintained. Only females with endogenous estradiol and progesterone demonstrated increased locomotor activity after cocaine challenge. Estradiol replacement enhanced stereotyped behaviors after repeated cocaine administration. Cocaine sensitization of stereotyped behaviors in female rats was reduced after progesterone replacement, either alone or concomitant with estradiol. The behavioral responses (locomotion and stereotypy) to cocaine were affected differently, depending on whether the female hormones were of an endogenous or exogenous origin. Therefore, hormonal cycling appears to be an important factor in the sensitization of females. Although estradiol increases the risk of cocaine sensitization, progesterone warrants further study as a pharmacological treatment in the prevention of psychostimulant abuse

Clinical subtypes of obsessive-compulsive disorder based on the presence of checking and washing compulsions Subtipos clínicos do transtorno obsessivo-compulsivo com base na presença de compulsões de checagem e lavagem

OBJECTIVE: We aimed at examining the utility of checking and washing compulsions as markers of valid subtypes of obsessive-compulsive disorder (OCD). METHODS: One hundred and six patients with obsessive-compulsive disorder were evaluated with a socio-demographic and clinical questionnaire, the Structured Clinical Interview for DSM-IV, the Yale-Brown Obsessive-Compulsive Scale, the Clinical Global Impression, the Beck Depression Inventory, the Hamilton Rating Scale for Depression, and the Global Assessment of Functioning. These individuals were allocated in one of four subgroups [checkers (OCD-Ch; n = 20), washers (OCD-Wa; n = 13), checkers and washers (OCD-CW; n = 48), and non-checkers and non-washers (OCD non-CW = 25)] on the basis of the presence and the clinical relevance of checking and/or washing compulsive behaviors across their lifetime. Socio-demographic and clinical variables were compared and contrasted between the groups by means of ANOVA followed by post-hoc Least Significant Difference or Dunnett's tests for continuous variables and chi-square tests followed by partitioned chi-square tests for categorical variables. RESULTS: OCD-Ch and OCD-Wa did not differ on most demographic and clinical features, the only exception being the number of different types of obsessions, which were significantly higher in the former group. The OCD-CW group was more likely to exhibit an insidious onset of obsessive-compulsive symptoms, to manifest itself as a mixed subtype of obsessive-compulsive disorder and to display obsessions with contamination themes. On the other hand, the OCD non-CW group was more likely to exhibit an acute onset, a shorter duration of illness, obsessions with religious themes, an episodic course, and less severe obsessive-compulsive symptoms. CONCLUSIONS: In our sample, the probing of the presence of checking and/or washing compulsions has provided significant empirical support to establish valid subtypes of obsessive-compulsive disorder.<br>OBJETIVO: Nós investigamos a utilidade das compulsões de verificação e de lavagem como marcadores de subtipos válidos do transtorno obsessivo-compulsivo (TOC). MÉTODOS: Cento e seis pacientes com transtorno obsessivo-compulsivo foram avaliados com um questionário sociodemográfico e clínico e com a entrevista clínica estruturada para o DSM-IV, a escala de sintomas obsessivo-compulsivos de Yale-Brown, a escala de impressão clínica global, o inventário de depressão de Beck, a escala para avaliação de depressão de Hamilton e a avaliação global de funcionamento. Estes indivíduos foram incluídos em um dos seguintes subgrupos: verificadores (TOC-Ver; n = 20), lavadores (TOC-Lav; n = 13), verificadores e lavadores (TOC-VL; n = 48) e não-verificadores e não-lavadores (TOC-NVL = 25). Esta classificação foi realizada com base na presença e relevância clínica de compulsões de verificação e de lavagem ao longo da vida dos pacientes. As variáveis sociodemográficas e clínicas foram comparadas e contrastadas entre os subgrupos através de uma ANOVA seguida pelos testes LSD ou Dunnett para variáveis contínuas e do teste do qui-quadrado seguido pelo qui-quadrado particionado para variáveis categóricas. RESULTADOS: Os pacientes com TOC-Ver e os pacientes com TOC-Lav não diferiram significativamente entre si na maioria das variáveis incluídas no estudo, com exceção do número de diferentes tipos de obsessões, significativamente maior nos primeiros. Os pacientes com TOC-VL exibiram, com maior freqüência, um início insidioso, o subtipo misto de TOC segundo a CID-10 e obsessões de contaminação. Pacientes com TOC-NVL apresentaram, com maior freqüência, um início súbito, menor duração de sintomas, obsessões de conteúdo religioso, curso episódico e sintomas obsessivo-compulsivos menos graves. CONCLUSÕES: A investigação quanto à presença de compulsões de verificação e lavagem sugeriu que estes sintomas podem contribuir para validar subtipos de transtorno obsessivo-compulsivo

The Use of Bright and Dark Types of Humour is Rooted in the Brain

The ways in which humour can be used are related to the manifold interpersonal functions humour can serve, some of which are positive, and some negative. In the present study, phasic changes in the functional coupling of prefrontal and posterior cortex (EEG coherence) during other people's auditory displays of happy and sad mood were recorded to predict people's typical use of humour in social interactions. Greater use of benevolent humour, the intentions of which are in keeping with the characteristics of "laughing-with" humour, was associated with greater decreases of prefrontal-posterior coupling during the processing of happy laughter. More loose prefrontal-posterior coupling indicates loosening of control of the prefrontal cortex over the incoming perceptual information, thereby opening up the perceptual gate and allowing the brain to become more affected by the social-emotional signals. Greater use of humour styles linked to malicious intentions of "laughing-at" humour was associated with responses indicating a wider opened perceptual gate during the processing of other people's crying. The findings are consistent with the idea that typical humour styles develop in line with the rewarding values of their outcomes (e.g., interaction partners are happy or hurt), which in turn are defined through the individuals' latent interpersonal goals