GABA(A) receptor neurotransmission dysfunction in a mouse model of social isolation-induced stress: possible insights into a non-serotonergic mechanism of action of SSRIs in mood and anxiety disorders

Protracted social isolation in laboratory animals causes stress, which induces a variety of behavioral abnormalities including increased aggressiveness, anxiety-related behaviors, cognitive deficits and hyper locomotion. Many of these disorders are similar to the symptoms found in psychiatric disorders, such as depression, anxiety, premenstrual dysphoria and posttraumatic stress disorders (PTSD). Recent studies have demonstrated that male mice that have been socially isolated for more than 4 weeks show: (a) reduced responsiveness of GABA(A) receptors (GABA(A)-R) to the administrations of GABA mimetic drugs at GABA(A)-R; (b) downregulated biosynthesis of 3alpha,5alpha-tetrahydroprogesterone (3alpha,5alpha-THP) (allopregnanolone: ALLO), a neurosteroid with a potent positive allosteric modulatory effect on the action of GABA on GABA(A)-R; and (c) alterations in the expression of GABA(A)-R subunits (i.e. a decrease of alpha1/alpha2 and gamma2 subunits and an increase of alpha4 and alpha5 subunits). The selective serotonin reuptake inhibitor (SSRI) fluoxetine (FLX) and its congener norfluoxetine (Nor-FLX), when administered systemically at nmol/kg doses, normalize the reduced content of brain ALLO and the reduced responsiveness of GABA(A)-R to GABA mimetic drugs (i.e. pentobarbital) and also attenuate aggressive behavior in socially isolated mice in a stereospecific manner. Although these compounds inhibit ex vivo serotonin reuptake into brain tissue, their SSRI activities require high micromol/kg dose ranges and are not stereospecific. These studies suggest that in socially isolated mice, abnormalities of GABA(A)-R signal transduction are attributable to the downregulation of ALLO production and to a switch in heteropentameric GABA(A)-R subunit assembly composition. Hence, the normalization of ALLO biosynthesis may be a new target for the development of drugs effective for psychiatric disorders related to neurosteroid biosynthesis downregulation.     

Willingness to use microbicides varies by race/ethnicity, experience with prevention products, and partner type.

OBJECTIVE: To investigate women's willingness to use vaginal microbicides to reduce/prevent HIV infection, using measures grounded in the individual, behavioral, and social contexts of sex. DESIGN: A cross-sectional study that enrolled a sample (N = 531) of 18-55 year old Latina, African-American, and White women in the U.S. between October, 2004, and July, 2005. MAIN OUTCOME MEASURES: Willingness to use microbicides and individual- and context-related variables (e.g., demographics, relationship status). RESULTS: Exploratory and confirmatory factor analyses supported a one-dimensional, 8-item scale, with high internal consistency (alpha = .91). Subgroup analyses within the Latina (n = 166), African- American (n = 193), and White sub-samples (n = 172) also supported a unidimensional scale with strong internal validity and high reliability. Race/ethnicity as a contextual factor, a woman's history of using prevention products, and the nature of the sexual partnership were predictive of willingness to use microbicides (R = .41). That is, women with greater frequencies of condom use, a history of spermicide use, and non-main sexual partners had higher predicted Willingness to Use Microbicides scale scores, while White women had lower predicted scores. CONCLUSION: The Willingness to Use Microbicides scale serves as the first psychometrically validated measure of factors related to microbicide acceptability. Developing and implementing psychometrically validated and contextualized microbicide acceptability measures, in an effort to understand microbicide users and circumstances of use, is crucial to both clinical trials and future intervention studies.     

What is an affective artifact? A further development in situated affectivity

In this paper I would like to propose the notion of “affective artifact”, building on an analogy with theories of cognitive artifacts (cf. Casa     

From pregnancy to motherhood: The structure of representative and narrative change

The aim of this work was to identify ways of objectifying the course of mothers' represen tations of their babies and themselves as mothers during pregnancy and the postpartum period. A sample of 51 women attending a Family Guidance Clinic for psychoprophylaxis courses was studied using semistruc tured interviews that were administered in the 7th month of pregnancy and on the 5th day and in the 4th month postpartum. This paper describes a method for classifiying themes identified in the mothers' representations of the baby and of the self-as-mother as wish-organized, defense-organized, fear-organized, or disorganized. This classification derives from the presumed clinical function of the narrative themes in the mothers' representational world. Themes about the baby and about the self-as-mother were primarily fear-organized at the 7th month of pregnancy. On the 5th day postpartum, there was no prevailing thematic organization. At 4 months postpartum, representations of the baby were primarily fear-organized and almost never disorganized. We speculate that themes about the baby and the self-as-mother that are disorganized may have negative prognostic significance.     

Using online social media,Facebook, in screening for major depressive disorder among college students

This study explored the feasibility of using Internet social networking media in an online program for Major Depressive Disorder (MDD) screening and psychoeducation targeting college students. A Facebook advertisement targeted students at five colleges in the United States to complete a mental health research survey that screened for MDD using the Patient Health Questionnaire-9 (PHQ-9). Students who screened positive for MDD were offered an eightweek follow-up survey. Of the 259 students who consented to participate in the study, 26.7% screened positive for MDD, while only 14.2% were receiving treatment. The use of Facebook to advertise for online screening for MDD required very little start-up time, and the average cost was $11.45 per subject recruited. It is feasible to use online, commercially available social networking media such as Facebook for online screening for MDD among college students. However, conducting online screening and offering treatment resources alone did not increase treatment rate in this population.     

Neural correlates of attention to emotional facial expressions in dysphoria

The present study investigated whether dysphoric individuals have a difficulty in disengaging attention from negative stimuli and/or reduced attention to positive information. Sad, neutral and happy facial stimuli were presented in an attention-shifting task to 18 dysphoric and 18 control participants. Reaction times to neutral shapes (squares and diamonds) and the event-related potentials to emotional faces were recorded. Dysphoric individuals did not show impaired attentional disengagement from sad faces or facilitated disengagement from happy faces. Right occipital lateralisation of P100 was absent in dysphoric individuals, possibly indicating reduced attention-related sensory facilitation for faces. Frontal P200 was largest for sad faces among dysphoric individuals, whereas controls showed larger amplitude to both sad and happy as compared with neutral expressions, suggesting that dysphoric individuals deployed early attention to sad, but not happy, expressions. Importantly, the results were obtained controlling for the participants' trait anxiety. We conclude that at least under some circumstances the presence of depressive symptoms can modulate early, automatic stages of emotional processing.     

Role of the dorsal hippocampus in object memory load

The dorsal hippocampus is crucial for mammalian spatial memory, but its exact role in item memory is still hotly debated. Recent evidence in humans suggested that the hippocampus might be selectively involved in item short-term memory to deal with an increasing memory load. In this study, we sought to test this hypothesis. To this aim we developed a novel behavioral procedure to study object memory load in mice by progressively increasing the stimulus set size in the spontaneous object recognition task. Using this procedure, we demonstrated that naive mice have a memory span, which is the number of elements they can remember for a short-time interval, of about six objects. Then, we showed that excitotoxic selective lesions of the dorsal hippocampus did not impair novel object discrimination in the condition of low memory load. In contrast, the same lesion impaired novel object discrimination in the high memory load condition, and reduced the object memory span to four objects. These results have important heuristic and clinical implications because they open new perspective toward the understanding of the role of the hippocampus in item memory and in memory span deficits occurring in human pathologies, such as Alzheimer's disease and schizophrenia.