Glucocorticoids are required for extinction of predator stress-induced hyperarousal

Background

The role of glucocorticoids in extinction of traumatic memories has not been fully characterized despite its potential as a therapeutic target for acquired posttraumatic stress disorder (PTSD). The predator stress paradigm allows us to determine whether glucocorticoids mediate the extinction of both context-dependent and context-independent fear memories.

Methods

Male C57BL/6J mice were exposed to a predator (cat) then repeatedly exposed to the predator stress context in the absence of the cat. Context-dependent (associative) fear memory was assessed as suppression of activity during re-exposure to the predator stress context without the cat (extinction trials). Context-independent fear (non-associative) was assessed seven days after extinction trials using measures of hyperarousal and anxiety-like behaviours in environments unlike the predator stress context. To assess the role of glucocorticoids, mice were injected with metyrapone (50 mg/kg) 90 min prior to extinction trials in predator stressed mice and context-dependent and context-independent fear memories were assessed. Finally, metyrapone-treated predator stressed mice were injected with corticosterone (5 or 10 mg/kg) immediately following extinction trials and context-dependent and context-independent fear memories were assessed.

Results

Repeated re-exposure to the predator stress context without the cat present extinguished context-dependent fear memory, and also reduced hyperarousal, a generalized, chronic PTSD-like symptom. We show that extinction of context-independent predator stress-induced hyperarousal is dependent on endogenous glucocorticoids during the extinction trials. Furthermore, the inhibition of extinction by metyrapone on startle amplitude was reduced by exogenous administration of corticosterone following extinction trials. Overall, these data implicate glucocorticoids in the extinction of hyperarousal, a core symptom of PTSD.     

Comparing observational software with paper and pencil for time-sampled data: A field test of Interval Manager (INTMAN)

In this article, we describe the Interval Manager (INTMAN) software system for collecting timesampled observational data and present a preliminary application comparing the program with a traditional paper-and-pencil method. INTMAN is a computer-assisted alternative to traditional paper-and-pencil methods for collecting fixed interval time-sampled observational data. The INTMAN data collection software runs on Pocket PC handheld computers and includes a desktop application for Microsoft Windows that is used for data analysis. Standard analysis options include modified frequencies, percent of intervals, conditional probabilities, and kappa agreement matrices and values. INTMAN and a standardized paper-and-pencil method were compared under identical conditions on five dimensions: setup time, duration of data entry, duration of interobserver agreement calculations, accuracy, and cost. Overall, the computer-assisted program was a more efficient and accurate data collection system for time-sampled data than the traditional method.     

Attention to components or compounds as a factor in discrimination transfer performance.

Prior to being tested with standard reversal or extradimensional (ED) shift procedures, two groups of mentally retarded subjects (MA: 4 to years) were pretrained using two different methods. The Component group received two problems which could be solved easily only by attending to the form components. The Compound group was trained on two problems requiring attention to compound color-form cues. It was assumed that the two solution modes would carry over to the third problem, which was for both groups a standard form discrimination with color variable and irrelevant within settings. The fourth problem was either an ED shift or a reversal. The Component group learned reversal faster than ED shift whereas the opposite was true for the Compound group. Subproblem analyses of ED shift performance showed dependent settings for the Component group and independent settings for the Compound group. Results are consistent with the view that compound and component solutions of discriminative problems are achieved by attention to the abstract dimensions of compounds or components and that attention to either of these dimensions can be trained at higher or lower developmental levels even though the salience of the compound dimension may be initially greater for lower level subjects.     

Lateral-frontal slow potential shifts preceding language acts in deaf and hearing adults

Slow potential EEG shifts (SPSs) recorded over Broca's area and the paired contralateral site preceding cued language acts have been reported to identify the language-dominant hemisphere. A contingent negative variation paradigm SPS method was applied to the comparative study of 10 hearing adults and of 10 adult prelingually deaf persons whose first learned language was American Sign Language. Volunteers performed both language and non-language acts in both oral and manual expressive modes. The hearing group showed no lateralized SPS, failing to replicate previous reports. The deaf group showed a nonsignificant trend opposite in laterality to that of hearing groups in previous reports.     

Preventing AIDS via Education

AIDS (Acquired Immune Deficiency Syndrome) education is the only effective method of reducing the transmission of HIV (human immunodeficiency virus) disease. The authors of this article compare the AIDS epidemic to past epidemics, including social and political responses. Populations at risk for HIV infection are identified, and the authors discuss current social and economic factors affecting AIDS education programs. Recommendations are made and resources are identified for starting a community-based AIDS education program.     

The Femininity Ideology Scale: Factor Structure, Reliability, Convergent and Discriminant Validity, and Social Contextual Variation

This study reports on the psychometric properties of the Femininity Ideology Scale (FIS) from the responses of 407 undergraduate participants in the USA. Factor analysis supported the five factor structure. Cronbach alpha coefficients of the factors and total scale were adequate. Support for discriminant validity was found after examining the relationship between the FIS and the Bem Sex Role Inventory, which measures feminine traits. Support for convergent validity was found after examining, first, with the entire sample, the relationships between the FIS and the Male Role Norm Inventory, and second, with the female sample, the relationships between the FIS and the Feminist Identity Development Scale. We also found that FIS scores vary in relationship to the social contextual variables of race/ethnicity and sex.     

“Editing” Genes: A Case Study About How Language Matters in Bioethics

Metaphors used to describe new technologies mediate public understanding of the innovations. Analyzing the linguistic, rhetorical, and affective aspects of these metaphors opens the range of issues available for bioethical scrutiny and increases public accountability. This article shows how such a multidisciplinary approach can be useful by looking at a set of texts about one issue, the use of a newly developed technique for genetic modification, CRISPRcas9.     

Luminance affects age-related deficits in object detection: implications for computerized psychological assessments

As psychological instruments are converted for administration on computers, differences in luminance and contrast of these displays may affect performance. Specifically, high-luminance assessments may mask age-group differences that are apparent under lower luminance conditions. We examined the effects of luminance and contrast on object detection using computerized and naturalistic assessments. Younger and older adults displayed more differences in performance across differing contrast levels in conditions that were matched for luminance, despite the conditions appearing perceptually different. These findings indicate that computerized assessments should be created with luminance levels that are similar to those of the tasks they purport to simulate in order to enhance their validity.