Comparison of corticosterone responses to acute stressors: Chronic jugular vein versus trunk blood samples in mice

A commonly used method for obtaining blood samples from mice is decapitation. However, there is an obvious need for repeated blood sampling in mice under stress-free conditions. Here, we describe a simple technique to repeatedly collect blood samples from conscious, freely moving mice through a chronically implanted jugular vein catheter. Furthermore, we compare plasma corticosterone (CORT) concentrations in samples obtained through the catheter 1 day after surgery with samples taken from trunk blood obtained under basal or acute stress conditions. CORT concentrations in repeated 100-μl venous blood samples were found to be similar to trunk blood samples both under basal conditions and after stressor exposure collected at identical time points (at 5, 15, and 60?min). Using both techniques, we demonstrate a progressive increase in CORT levels until 15?min after termination of stressor exposure and a decrease towards baseline values 60?min later. Anxiety-related behavior, as assessed on the elevated plus maze 3-4 days after surgery, did not differ between catheterized and non-catheterized mice. Our results provide evidence for application of jugular vein catheterization as a technique for repeated blood sampling in conscious laboratory mice. Use of this technique will greatly reduce the number of animals required for experiments involving endocrine endpoints.     

Extinction treatment in multiple contexts attenuates ABC renewal in humans

Renewal has been implicated as one of the underlying mechanisms in return of fear following exposure therapy. ABC renewal is clinically more relevant than ABA renewal and yet it is a weaker form of renewal, suggesting that conducting extinction treatment in multiple contexts may be sufficient to attenuate ABC renewal. Using self-reported expectancy of shock and startle blink responses the current study examined the effects of conducting extinction treatment in multiple contexts on ABC fear renewal. Participants (N = 68) received conditional stimulus (CS) and unconditional stimulus (US) pairings in one context (A) followed by extinction treatment (CS presentations alone) in either one other context (B) or three other contexts (BCD). Non-reinforced test trials in a novel context (E) resulted in renewal of extinguished conditioned behaviour for those who received extinction in only one context. However, renewal was attenuated for those who received extinction treatment in three contexts. No renewal was found for the control group that received the test trial in the same context as during extinction. Suggestions are provided for clinicians seeking to prevent or attenuate return of fear following exposure therapy.     

Method effects: the problem with negatively versus positively keyed items

Using confirmatory factor analyses, we examined method effects on Rosenberg's Self-Esteem Scale (RSES; Rosenberg, 1965) in a sample of older European adults. Nine hundred forty nine community-dwelling adults 60 years of age or older from 5 European countries completed the RSES as well as measures of depression and life satisfaction. The 2 models that had an acceptable fit with the data included method effects. The method effects were associated with both positively and negatively worded items. Method effects models were invariant across gender and age, but not across countries. Both depression and life satisfaction predicted method effects. Individuals with higher depression scores and lower life satisfaction scores were more likely to endorse negatively phrased items.     

Exercise imagery and its correlates in older adults

Objectives

The purpose of the present study was to test a structural model examining the interrelationships between exercise imagery, self-reported exercise behaviour and well-being in older adults.

Design

Cross-sectional survey.

Method

Participants were 499 older Greek adults (50.10% males) aged between 51 and 84 years (M age = 57.31; SD = 5.52) who completed questionnaires measuring exercise imagery use, exercise behaviour, subjective vitality, and physical self-worth. The relationship between these variables was tested with a structural model based on the applied model of imagery use for exercise (Munroe-Chandler & Gammage, 2005).

Results

Energy imagery positively predicted exercise behaviour and subjective vitality, and appearance and technique imagery positively predicted physical self-worth.

Conclusions

These results indicate older adults engage in different types of imagery to motivate themselves to exercise and improve their well-being, thus implying that the content of imagery interventions should be specifically tailored to the outcomes older adults wish to realise for interventions to be effective.     

Maternal soothing and infant stress responses: soothing, crying and adrenocortical activity during inoculation

The relation between maternal soothing and infant stress response during inoculation was examined in a sample of 37 mothers and their 3-month-old infants. The mothers' soothing and the infants' cry vocalizations and the mothers' and the infants' salivary cortisol level pre- and post-injection were analysed. There was a positive relation between infants' cry vocalization post-injection and maternal soothing pre- and post-injection. The sample was divided in two sub-groups depending on whether the mothers evidenced most soothing of the infants in the period before (Preparatory group; n=20) or after (Contingent group; n=17) the syringe injection. In the Preparatory group, the duration of infant cry vocalizations was related to amount of maternal soothing before and after the injection, while cry vocalizations in the Contingent group was related to amount of maternal soothing after the injection. The Contingent infants responded to the injection with a significant increase in cortisol, while there was no increase in the Preparatory infants. The Preparatory infants evidenced significantly longer duration of looking at the target stimuli in a visual marking task, suggesting greater difficulties in disengaging attention. These findings indicate that 3-month-olds' stress responses and their mothers' situational behaviour are mutually regulated.     

Contributions of impulsivity and callousness in the assessment of adjudicated male adolescents: a prospective study

This study examined whether delinquent adolescents with low scores on personality scales related to callousness and impulsivity would show less antisocial behavior and better psychosocial functioning compared to those elevated on 1 or both scales. A group of 162 White and African American male adolescents, recently adjudicated in a southern youth court system, were assessed at baseline and at 18-month follow-up. Dependent variables included measures of antisocial and prosocial behaviors, days detained in juvenile detention, and symptoms of psychopathology. As hypothesized, adolescents low on both callousness and impulsivity spent fewer days detained and reported less antisocial behavior and fewer symptoms of psychopathology compared to those high on I or both scales. Finally, African American participants were detained for more days, but did not report significantly more antisocial behaviors or symptoms of psychopathology compared to the White adolescents. The results suggest that being low on callousness and impulsivity may serve a protective role for future delinquent behavior for both African American and White adolescents.     

Reconstruing the "reconstruction" of psychopathy: a comment on Cooke, Michie, Hart, and Clark

In this comment we highlight critical problems in the estimation of parameters for their hierarchical three-factor model of psychopathy, as assessed with the Hare Psychopathy Checklist, and their interpretation of these factors as causally related to socially deviant behavior. We argue that there is nothing "causal" about a model in which cross-sectional data are used to assert that antisocial tendencies are consequences of other more fundamental psychopathic traits. We present an equally viable model, based on the PCL-R four-factor solution, in which antisocial tendencies play a fundamental role in the construct of psychopathy, consistent with previous research and clinical tradition.     

Cortical plasticity associated with stuttering therapy

Neuroimaging studies have indicated that persistent developmental stuttering (PDS) may be associated both with an abnormality in white matter of left-hemispheric speech areas and a right-hemispheric hyperactivity. The latter may compensate for the deficient structural connectivity in the left hemisphere. To investigate the effects of stuttering therapy on brain activity nine male adults with PDS underwent functional magnetic resonance imaging (fMRI) before and within 12 weeks after fluency shaping therapy. Brain response differences during overt sentence reading before and after therapy were assessed by utilizing random effects analyses. After therapy, a more widespread activation was observed in frontal speech and language regions and temporal areas of both hemispheres, particularly and more pronounced on the left side. Interestingly, distinct posttreatment left-sided activation increases were located directly adjacent to a recently detected area of white matter anomaly [M. Sommer, M.A. Koch, W. Paulus, C. Weiller, C. Buchel (2002). Disconnection of speech-relevant brain areas in persistent developmental stuttering. The Lancet, 360, 380-383] suggesting that fluency shaping techniques reorganize neuronal communication between left-sided speech motor planning, motor execution, and temporal areas. Hence, a therapeutic mechanism can be assumed to remodel brain circuitry close to the source of the dysfunction instead of reinforcing compensation via homologous contralateral brain networks. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to: (1) describe brain activation changes detected shortly after fluency-shaping therapy; (2) identify left-hemispheric regions where a (re)functionalization after fluency-shaping therapy seems to occur adjacent to a recently described abnormal white matter region in PDS subjects; and (3) discuss how an effective cerebral compensation mechanism for stuttering could work.