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Adolescence is thought of as a stress-sensitive developmental period. While many studies have compared adolescent responses to stress relative to that of adults, a growing body of work has examined stress responses in juveniles. Here we investigated if a chronic stressor has a differential effect on spatial memory in rats depending on whether it occurs during adolescence or the juvenile period. Male rats were exposed to the stress hormone corticosterone (Cort) in their drinking water, a vehicle control (2.5% ethanol), or water, for 7 days before being tested on a novel Object/Place task 6 days or 6 weeks later. Exposure to Cort or ethanol at either age impaired spatial memory at the 6-day test. The ethanol induced impairment was attenuated 6 weeks later. However, rats given Cort during adolescence, but not the juvenile period, were still impaired. Together, these results suggest that adolescence is indeed a stress-sensitive period.

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Anger is often associated with approach motivation, and most self-report scales measuring trait anger tap this approach orientation. However, some research has suggested that individuals occasionally experience anger and respond with avoidance motivation. This suggests that individuals may differ in chronic tendencies toward responding to anger with avoidance. The current research introduces a new self-report instrument, the Avoidance Motivated Response to Anger Scale, designed to assess this trait. We report findings of four studies conducted with American and Polish individuals. The studies provide evidence of the scale's internal consistency, test-retest reliability, convergent validity, and discriminant validity.

The present research aimed to better understand individual differences in attitudes towards emotions with a focus on anger. We report findings of four studies conducted with American and Polish individuals. Results showed that individuals who have more positive attitudes toward anger are higher in trait anger (Studies 1–4), are more likely to think about getting revenge (Study 1), and expect that getting revenge will make them feel good (Studies 1–2). In addition, these individuals are lower in agreeableness and lower in the tendency to engage in avoidance when angered (Studies 1–4). They score lower in humility (Studies 3–4), lower in secure romantic attachment but higher in anxious and avoidance attachment (Study 3). Finally, they are more likely to believe a wide range of conspiracies (Studies 2–4). Discussion focuses on the implications of these results.

Reproductive experience leads to long-lasting changes in anxiety-like behaviour and fear extinction, the laboratory model of exposure therapy for anxiety disorders. For example, fear extinction is influenced by estrous cycle in nulliparous (no reproductive experience) female rats, but this effect is abolished in primiparous (one reproductive experience) females. It is unclear whether such changes are driven by pregnancy, maternal experience of caring for offspring during the postpartum period, or a combination of both experiences. The present study sought to determine the influence of maternal experience (i.e., exposure to pups and mother-pup interactions) on fear extinction in primiparous rats. In Experiment 1, we tested whether pup exposure is necessary to mitigate estrous effects on fear extinction in primiparous rats. Age-matched nulliparous rats, primiparous rats, and primiparous rats who experienced pregnancy but not pup exposure, underwent fear conditioning on day 1 (2 months post-parturition), extinction training during proestrus (high sex hormones) or metestrus (low sex hormones) on day 2, and extinction recall on day 3. Replicating past research, nulliparous rats showed impaired extinction recall when they were extinguished during metestrus compared to proestrus. In contrast, primiparous rats with and without pup exposure showed comparable extinction recall irrespective of estrous phase. In Experiment 2, we assessed whether naturally-occurring variation in mother-pup interactions predict future fear extinction performance and anxiety-like behaviour. During the first week of lactation, primiparous rats were measured for maternal behaviours toward pups. Primiparous rats were then tested on the light-dark box and elevated plus maze to measure anxiety-like behaviour and underwent a fear extinction protocol 1 month post-weaning. We found no significant correlations between maternal behaviour and fear extinction outcomes or anxiety-like behaviour. Our findings suggest that pregnancy, not maternal experience, mitigates the impact of estrous cycle on fear extinction. In addition, natural variation in maternal experience does not appear to contribute to variability in future fear extinction outcomes or anxiety-like behaviour in primiparous rats.

Individual differences in parental care predict variations in offspring anxiety across species. Here, we examined whether between‐ and within‐litter variations in maternal licking (a measure of rodent maternal care) predict infant rats’ retention of an aversive association (a predictor of later anxiety‐like behavior) and whether the relationship between maternal licking and infant fear memory is moderated by variations in infants’ solicitation of maternal care. Unique marks were drawn on each pup, coded for fading, and touched up daily across the first week of life. Mark fading was used as an index of maternal licking where greater fading suggested more maternal licking the previous day. Separation‐induced ultrasonic vocalizations (USVs) were recorded to measure individual differences in solicitation of maternal care. Infants were fear conditioned at postnatal day (P) 17 and tested for fear of the conditioned stimulus (CS) 1 week later. Across litters, mark fading negatively predicted CS‐elicited fear at test for male, but not female, offspring. This relationship was moderated by number of USVs emitted at P1, such that mark fading only predicted CS‐elicited fear for males that emitted a low number of USVs. These results suggest that offspring solicitation may moderate the relationship between maternal care and fear/anxiety.

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