Maternal Care and Individual Differences in Defensive Responses

Abstract— Familial transmission of mental illness is common. Recent studies in behavioral neuroscience and biological psychiatry reveal the importance of epigenetic mechanisms of transmission that center on the developmental consequences of variations in parental care. Studies with rats suggest that environmental adversity results in patterns of parent–offspring interactions that increase stress reactivity through sustained effects on gene expression in brain regions known to regulate behavioral, endocrine, and autonomic responses to stress. While such effects might be adaptive, the associated cost involves an increased risk for stress-related illness.     

Differential sensitivity to the effects of nicotine and bupropion in adolescent and adult male OF1 mice during social interaction tests

Few studies have compared the action of both nicotine (NIC) and bupropion (BUP), an antidepressant used to treat NIC dependence, on social and aggressive behavior at different ages. This study aims to determine whether these drugs produce differential effects in adolescent (postnatal day: 36-37) and adult (postnatal day: 65-66) mice that have been housed individually for 2 weeks in order to induce aggressive behavior. Mice received BUP (40, 20, or 10 mg/kg), NIC (1, 0.5, and 0.25 mg/kg as base), or vehicle earlier to a social interaction test. BUP (40 mg/kg) decreased social investigation and increased nonsocial exploration in both adolescent and adult mice. The same effects were also observed in adult mice administered with a lower dose of the same drug (20 mg/kg). In adolescents, NIC (1 mg/kg) decreased social investigation, but this effect did not reach statistical significance in adults. In conclusion, a differential sensitivity to the effects of NIC or BUP emerged in some of the behavioral categories when the two age groups were compared.     

认知功能的性别差异

我们了概述认知功能的性别差异, 尤其是情节记忆功能的性别差异。已有的研究结果表明女性在言语生成、情节记忆、面孔识别任务中比男性存在明显的优势, 而男性的优势则表现在视空间任务中, 如视空间情节记忆任务。本文批判性地讨论了一个流行的假设: 类固醇激素影响认知功能的性别差异, 得出的结论是内源性睾丸激素或雌二醇均未显著影响认知功能的性别差异。     

Investigating the outcome of the initial assessment at a national transgender health service: Time to review the process?

Background: Globally, there is a lack of a standardized assessment process prior to the initiation of gender affirming medical interventions and consequently there is a discrepancy in this process among different transgender health services.

Aim: The main objective of this study is to investigate the outcome of the initial assessment process at a national transgender health service.

Method: The outcome of people over the age of 17 years, assessed at a large national transgender health service in the United Kingdom during a 2-year period was categorized into: (1) recommendation for cross-sex hormone treatment, or (2) no recommendation for cross-sex hormone treatment. In addition, 200 case notes were reviewed in order to investigate the level of agreement between the two clinicians involved in the assessment process.

Results: During the study period, a total number of 617 people completed their assessment at the service. Following assessment 380 (61.6%) patients were recommended for cross-sex hormone treatment, leaving 237 (38.4%) patients who required a longer assessment period or were discharged. The factors associated with being recommended for cross-sex hormone treatment were having socially transitioned, not smoking, having initiated cross-sex hormones prior to assessment, being older, and assigned male at birth. Out of the 200 case notes reviewed, agreement between assessor 1 and 2 (3 months apart) was found in 88% (n = 176) of the cases.

Discussion: Although the results of the study may not be generalizable to other international centers, questioning the assessment process and the role of the assessors is important to ensure treatment is offered in a timely and efficient manner. The findings from this study suggest that the routine inclusion of two assessors needs to be reviewed.     

Role of estrogen in balancing contributions from multiple memory systems

In addition to modulating memory per se, estrogen alters the learning strategy used to solve a task, thereby regulating the quality of information processed by the brain. This review discusses estrogen's actions on cognition within a memory systems framework, highlighting our work with a variety of paradigms showing that learning strategy is sensitive to estrogen even when learning rate is not. Specifically, high levels of gonadal steroids, in particular, elevations in estrogen, bias female rats toward using hippocampal-sensitive approaches while low levels of gonadal steroids promote the use of non-hippocampal sensitive strategies. In light of findings from a variety of approaches involving the hippocampus in allocentric and the striatum in egocentric response patterns, it is likely that estrogen alters the relative participation of these, and most undoubtedly other, neural systems during cognition. Changes in neuromodulators such as acetylcholine that regulate other processes such as inhibitory tone and excitability reflect one mechanism by which estrogen may orchestrate learning and memory.     

Early life predictors of callous-unemotional and psychopathic traits

Psychopathy is a disorder that occurs primarily in males. Offenders with psychopathic traits are responsible for a disproportionate amount of crime in society, particularly violent crime. Early childhood is a time when individual differences in empathy and guilt—key indicators of the construct of psychopathy—are first evident. A growing number of longitudinal studies have begun to investigate how factors in infancy and early childhood predict psychopathic-like traits in later childhood, adolescence, and adulthood. These studies have suggested that parenting styles during infancy (parental sensitivity, maternal harsh intrusion, commenting on the emotional state of the child) as well as attachment styles are predictive of later psychopathic-like traits. In addition, child characteristics such as temperament and the functioning of biological systems such as the autonomic nervous system and hypothalamic–pituitary–adrenal axis are predictive. Overall, studies have suggested that at least some of the origins of psychopathic traits are present in infancy and early childhood, which is consistent with the perspective of psychopathy as a neurodevelopmental disorder. A recent evolutionary-developmental model provides hypotheses regarding how psychopathy may develop and why it is more common in males than females. This model, and its implications for intervention, is discussed in the context of the longitudinal studies that have been conducted on psychopathy.     

An olfactory discrimination procedure for mice

This paper describes an olfactory discrimination procedure for mice that is inexpensively implemented and leads to rapid discrimination learning. Mice were first trained to dig in small containers of sand to retrieve bits of buried chocolate. For discrimination training, two containers were presented simultaneously for eight trials per session. One container held sand mixed with cinnamon, and the other held sand mixed with nutmeg. Both containers were baited with chocolate buried in the sand. One odor was designated S+, and mice were allowed to dig and retrieve the chocolate from this container. The other odor was S-, and both containers were removed immediately if subjects began to dig in an S- container. After meeting a two-session acquisition criterion, subjects were given a series of discrimination reversals. In Experiment 1, 12 Swiss-Webster mice (6 male and 6 female) acquired the olfactory discrimination in three to five sessions and completed 3 to 10 successive discrimination reversals within a 50-session testing limit. In Experiment 2, subjects were 14 Pah(enu2) mice, the mouse mutant for phenylketonuria; 7 were homozygotes in which the disorder was expressed (PKU), and 7 were heterozygotes with normal metabolism (non-PKU). Thirteen mice completed pretraining in four to seven sessions, acquisition required 3 to 12 sessions, and all mice completed at least three reversals. Learning rates were similar in PKU and non-PKU mice. We discuss issues related to implementation and several potentially useful procedural variations.     

Hormonal changes of intimate partner violence perpetrators in response to brief social contact with women

This study investigated whether men with a history of real-life aggressive, dominant behavior show increases in testosterone and cortisol levels after brief social contact with women. Furthermore, we tested the prediction that such changes in hormones would be larger than those observed previously in young male students. Sixty-seven male participants convicted of intimate partner violence (IPV) either had brief social contact with a female confederate (experimental condition) or a male confederate (control condition). We also performed meta-analyses to investigate whether IPV perpetrators' hormonal responses were larger than the typical responses of young male students in prior studies. All statistical analyses were preregistered. Change in testosterone did not differ across experimental conditions, and testosterone in the IPV perpetrators actually declined from baseline in the female confederate condition. Our meta-analysis showed that this testosterone decrease was different from the testosterone increase typically observed in young male students. The cortisol levels of IPV perpetrators did not change in response to contact with women. This result was consistent with our meta-analysis since young male students also did not experience a cortisol change in response to interactions with women. In sum, our findings provide no evidence that male IPV perpetrators exhibit larger hormone increases to brief interactions with women, although it is possible that the men in this sample did not perceive the social contact period as a courtship opportunity. These results suggest that hormone reactivity to social encounters may differ across subject populations and depend on how subjects perceive social situations within laboratory settings.