Stress during puberty boosts metabolic activation associated with fear-extinction learning in hippocampus, basal amygdala and cingulate cortex

Adolescence is characterized by major developmental changes that may render the individual vulnerable to stress and the development of psychopathologies in a sex-specific manner. Earlier we reported lower anxiety-like behavior and higher risk-taking and novelty seeking in rats previously exposed to peri-pubertal stress. Here we studied whether peri-pubertal stress affected the acquisition and extinction of fear memories and/or the associated functional engagement of various brain regions, as assessed with 2-deoxyglucose. We showed that while peri-pubertal stress reduced freezing during the acquisition of fear memories (training) in both sexes, it had a sex-specific effect on extinction of these memories. Moreover hippocampus, basal amygdala and cingulate and motor cortices showed higher metabolic rates during extinction in rats exposed to peri-pubertal stress. Interestingly, activation of the infralimbic cortex was negatively correlated with freezing during extinction only in control males, while only males stressed during puberty showed a significant correlation between behavior during extinction and metabolic activation of hippocampus, amygdala and paraventricular nucleus. No correlations between brain activation and behavior during extinction were observed in females (control or stress). These results indicate that exposure to peri-pubertal stress affects behavior and brain metabolism when the individual is exposed to an additional stressful challenge. Some of these effects are sex-specific.     

Inhibition of mTOR by rapamycin in the amygdala or hippocampus impairs formation and reconsolidation of inhibitory avoidance memory

Mammalian target of rapamycin (mTOR), a central regulator of protein synthesis in neurons, has been implicated in synaptic plasticity and memory. Here we show that mTOR inhibition by rapamycin in the basolateral amygdala (BLA) or dorsal hippocampus (DH) impairs both formation and reconsolidation of memory for inhibitory avoidance (IA) in rats. Male Wistar rats received bilateral infusions of vehicle or rapamycin into the BLA or DH before or after IA training or retrieval. Memory retention was tested at different time points after drug infusion. Rapamycin impaired long-term IA retention when given before or immediately after training or retrieval into the BLA. When infused into the DH, rapamycin produced memory impairment when given before training or immediately after retrieval. The impairing effects of post-retrieval rapamycin required memory retrieval and were not reversed by a reminder shock. The results provide the first evidence that mTOR in the BLA and DH might play a role in IA memory reconsolidation.     

Hippocampal metabolites and memory performances in patients with amnestic mild cognitive impairment and Alzheimer's disease

In patients with amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD), previous studies have reported the decrease of N-acetylaspartate (NAA) concentration and the increase of myo-inositol (MI) concentration using proton magnetic resonance spectroscopy (1H-MRS). However, it remains to be investigated what aspects of cognition these metabolite changes reflect. In this study we evaluated the correlations between the subtests of Wechsler Memory Scale-Revised (WMS-R) and the concentrations of NAA and MI. The study group was composed of 42 patients with aMCI and 67 patients with AD. 1H-MR spectra with a single voxel-point resolved spectroscopy (PRESS) at a short echo time were acquired from the bilateral hippocampi and posterior cingulate gyrus. Positive correlations were shown between the NAA concentration in the left hippocampus and verbal memory, visual memory, general memory, attention and delayed recall; and furthermore, between the NAA concentration in the right hippocampus and verbal memory and general memory. Negative correlations were shown between the MI concentration in the left hippocampus and verbal memory, general memory, and delayed recall, and between the MI concentration in the right hippocampus and verbal memory. There was no significant correlation between any subtest of WMS-R and these two metabolite concentrations in the posterior cingulate gyrus. These findings suggest that bilateral, especially left hippocampal NAA and MI concentrations are associated with memory dysfunction observed in patients with aMCI and AD. In contrast, NAA and MI concentrations in the posterior cingulate gyrus may be less related to memory function than those in the hippocampus.     

The design and analysis of state-trace experiments

State-trace analysis (Bamber, 1979) addresses a question of interest in many areas of psychological research: Does 1 or more than 1 latent (i.e., not directly observed) variable mediate an interaction between 2 experimental manipulations? There is little guidance available on how to design an experiment suited to state-trace analysis, despite its increasing use, and existing statistical methods for state-trace analysis are problematic. We provide a framework for designing and refining a state-trace experiment and statistical procedures for the analysis of accuracy data using Klugkist, Kato, and Hoijtink's (2005) method of estimating Bayes factors. The statistical procedures provide estimates of the evidence favoring 1 versus more than 1 latent variable, as well as evidence that can be used to refine experimental methodology.     

Algorithms for detecting concealed knowledge among groups when the critical information is unavailable

We examined whether the Concealed Information Test (CIT) may be used when the critical details are unavailable to investigators (the Searching CIT [SCIT]). This use may have important applications in criminal investigations (e.g., finding the location of a murder weapon) and in security-related threats (e.g., detecting individuals and groups suspected in planning a terror attack). Two classes of algorithms designed to detect the critical items and classify individuals in the SCIT were examined. The 1st class was based on averaging responses across subjects to identify critical items and on averaging responses across the identified critical items to identify knowledgeable subjects. The 2nd class used clustering methods based on the correlations between the response profiles of all subject pairs. We applied a principal component analysis to decompose the correlation matrix into its principal components and defined the detection score as the coefficient of each subject on the component that explained the largest portion of the variance. Reanalysis of 3 data sets from previous CIT studies demonstrated that in most cases the efficiency of differentiation between knowledgeable and unknowledgeable subjects in the SCIT (indexed by the area under the receiver operating characteristic curve) approached that of the standard CIT for both algorithms. We also examined the robustness of our results to variations in the number of knowledgeable and unknowledgeable subjects in the sample. This analysis demonstrated that the performance of our algorithms is relatively robust to changes in the number of individuals examined in each group, provided that at least 2 (but desirably 5 or more) knowledgeable examinees are included. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Those who laugh are defenseless: how humor breaks resistance to influence

Three experiments illustrate that humor in advertisements prevents the development of negative brand associations due to resistance. Previous research on humor in advertising suggested that humor can counter negative responses during ad processing, but less is known about the effect of humor on the development of negative brand associations in memory. Brand associations are important because there is often a time delay between ad exposure and brand decisions. We separately manipulated two typical aspects of humor processing, that is, distraction and positive affect, and examined their effects on the development of respectively negative and positive brand associations. All experiments were conducted with university students as participants. The results showed that resistance causes negative brand associations (Experiments 1 and 2), and humor prevents the development of these negative brand associations more than nondistracting positive stimuli and neutral stimuli (Experiment 2 and 3). The prevention of negative brand associations was caused by the distractive properties of humor. Irrespective of resistance, the positive affect engendered by humor enhanced positive brand associations. Experiment 3 showed that distraction and positive affect in humor uniquely contribute to brand preference. Together, these results illustrate that the effect of humor on resistance follows a two-step process: humor forestalls the development of negative brand associations because of its distractive properties (cognitive mechanism), and engenders positive brand associations because of its positive emotional outcomes (affective mechanism). These effects of humor on brand associations jointly promote brand preference.     

Midlife Sexuality Among Thai Adults: Adjustment to Aging in the Thai Family Context

The objective of the study is to assess views of age related changes in sexual behavior among married Thai adults age 53–57. Results are viewed in the context of life course theory. In-depth interviews were conducted with 44 Thai adults in Bangkok and the four regions of Thailand. Topics covered include changing sexual behavior with age, adjustment to this change, gender differences in behavior, attitudes toward commercial sex and other non-marital sexual partners, and condom use. Most respondents were aware of this change and saw a decrease in sexual activity and desire more often among women compared to men. At the same time, many respondents viewed sexuality as important to a marriage. Some respondents accepted the decrease in sexual activity and focused more on work, family and temple activities. Thai Buddhism was seen as an important resource for people who were dealing with changes due to aging. Other persons turned to other partners including both commercial and non-commercial partners. The influence of the HIV epidemic that began in the 1990s was seen in concerns about disease transmission with extramarital partners and consequent attitudes toward condom use. The acceptability of extramarital partners in the family and community ranged from acceptance to strong disapproval of extramarital relationships.     

A Randomized, Double-Blind, Crossover Comparison of MK-0929 and Placebo in the Treatment of Adults With ADHD

Objective: Preclinical models, receptor localization, and genetic linkage data support the role of D4 receptors in the etiology of ADHD. This proof-of-concept study was designed to evaluate MK-0929, a selective D4 receptor antagonist as treatment for adult ADHD. Method: A randomized, double-blind, placebo-controlled, crossover study was conducted in adults with primary ADHD. The primary end point was changed from baseline in total score on the Adult ADHD Investigator Symptom Rating Scale following a 4-week treatment regimen. Additional measures included Clinical Global Impression-Severity Scale, Hospital Anxiety and Depression Scale, and Brown Attention Deficit Disorder Scale and D4 genotype analysis. Results: No statistically significant treatment differences were found between MK-0929 and placebo in any of the primary or secondary assessments. Conclusion: Results from this study suggest that blockade of the D4 receptor alone is not efficacious in the treatment of adult ADHD.     

Psychometric properties of the questionnaire of sociocultural influences on the aesthetic body shape model (CIMEC-26) in female Spanish adolescents

The purpose of the present study was to analyse the psychometric properties of the 'Questionnaire of Sociocultural Influences on the Aesthetic Body Shape Model' (CIMEC-26) in a Spanish adolescent population. This questionnaire measures the influence of agents and situations that transmit the current aesthetic model, and assesses environmental influences favouring thinness. The CIMEC-26 was administered to a sample of 4031 female primary and secondary school students ranging in age from 10 to 17 years (M?=?14, SD?=?1.34). Results suggested that the CIMEC-26 has acceptable internal consistency (α?=?.93). The oldest group (15-17 years) had the highest scores on all factors and the highest total scores, suggesting greater influence of the aesthetic body shape model and higher vulnerability to social pressure to achieve it. Factor analysis suggested three moderately interrelated components of the scale. Confirmatory factor analysis showed that both the three-factor solution and the original five-factor structure had good fit indices, although the latter showed the best fit. The CIMEC-26 proved to be an effective instrument for research on the social influence on the aesthetic body model in female adolescents.