Testosterone intake and aggressiveness: Real effect or anticipation?

In a double-blind experiment, human males (n = 27) were given either testosterone (40 mg/day), placebo, or no treatment, over a one week period. Subjective and observer assessed mood estimations were conducted before and after treatment. Testosterone levels in saliva were measured with radioimmunoassay. The results revealed a significant placebo effect [c. f. Medicine and Science in Sports 4: 124–126]: After treatment, the placebo group scored higher than both the testosterone and the control group on self-estimated anger, irritation, impulsivity, and frustration. Observer-estimated mood yielded similar results. The lack of a placebo effect in the testosterone group is intriguing, and may be due to secondary effects caused by suppression of the body's own testosterone production, since recorded non-protein bound testosterone did not significantly rise due to treatment. The resultss suggest that androgen usage causes expectations, rather than an actual increase of aggressiveness. © 1994 Wiley-Liss, Inc.     

恐惧记忆习得与消退的性别差异及其神经机制

大多数人在其一生中都会经历创伤事件,但只有少数人会发展成为创伤后应激障碍（PTSD）。焦虑障碍的易感性和保护因素成为一个重要议题。基于恐惧记忆习得与消退模型的研究发现女性个体表现出“易习得、难消退”的特点。在恐惧相关脑区的脑生理结构、功能/结构连接性、以及大脑可塑性的性别差异可能是该特征的根本原因。性激素作为一种焦虑障碍的保护因素,可以调节这种性别差异,这种调节效应可能是通过影响大脑结构形态（如神经细胞的形态和数量）、调控与记忆相关基因的表达（如HDAC4）而实现的。雌性激素水平的不稳定性可能是女性易感焦虑障碍的重要原因。未来对性别差异的深入研究将有助于推进个性化医疗。     

Effects of chronic administration with high doses of testosterone propionate on behavioral and physiological parameters in mice with differing basal aggressiveness

The effects of testosterone propionate, an anabolic‐androgenic steroid, on the behavior displayed during a social encounter by gonadally intact male mice were investigated. Animals were distributed into three groups according to their attack latency in a pre‐screening test (high‐, moderate‐, and low‐ attacking mice) and each group received weekly injections of 60 or 120 mg/kg of testosterone or sesame oil for 10 weeks. Behavioral tests were then carried out. Afterwards, organs were weighed and blood samples collected in order to obtain hormonal data. Treatment had a differential impact on attack in the three groups of animals. Only the high‐attacking testosterone‐treated mice showed lower total duration of attack than their controls. Those that received 60 mg/kg spent more time exhibiting exploratory behaviors. As an index of the anabolic activity of the drug, all testosterone‐treated mice had heavier kidneys and, as an index of the androgenic activity of testosterone propionate, they had heavier seminal vesicles, lighter testes, and showed higher testosterone levels in a dose‐dependent way than their controls. Hence, the effect of treatment on peripheral physiological parameters was similar in all three groups whereas behavioral effects differed depending on basal aggressiveness, considered a characteristic of coping style. Aggr. Behav. 29:173–189, 2003. © 2003 Wiley‐Liss, Inc.     

Body checking behaviors in men

Males have been facing increasing pressure from the media to attain a lean, muscular physique, and are at risk for body dissatisfaction, disturbed eating and exercise behaviors, and abuse of appearance- and performance-enhancing drugs (APEDs). The aim of the current study was to examine the relationship between body checking and mood, symptoms of muscle dysmorphia, importance of shape and weight, and APED use in undergraduate males. Body checking in males was correlated with weight and shape concern, symptoms of muscle dysmorphia, depression, negative affect, and APED use. Body checking predicted APED use and uniquely accounted for the largest amount of variance in Muscle Dysmorphic Disorder Inventory (MDDI) scores (16%). Findings support the view that body checking is an important construct in male body image, muscle dysmorphia, and body change strategies and suggest a need for further research.     

Short-term estrogen treatment in ovariectomized rats augments hippocampal acetylcholine release during place learning

Estrogen modulates learning and memory in ovariectomized and naturally cycling female rats, especially in tasks using spatial learning and navigation. Estrogen also modulates cholinergic function in various forebrain structures. Past studies have shown positive correlations between hippocampal ACh output and performance on hippocampus-dependent tasks. The present study examined whether estradiol replacement would potentiate hippocampal ACh release during place learning. In vivo microdialysis and HPLC were used to measure extracellular ACh levels in the hippocampus of ovariectomized female rats that had received s.c. injections of 17beta-estradiol (10 microg) or sesame oil (vehicle treatment) 48 and 24h prior to training on a place task. Estrogen did not alter baseline levels of extracellular ACh in the hippocampus. During training, hippocampal ACh increased in ovariectomized rats regardless of estrogen status. However, while estradiol did not enhance learning in this experiment, estradiol significantly potentiated the increase in hippocampal ACh release seen during place training. This represents the first demonstration of on-line assessment of ACh output in hippocampus during learning in female rats and suggests that estrogen-dependent modulation of ACh release during training might control activation of different neural systems used during learning.     

EDITORS' INTRODUCTION

ABSTRACT

Transsexualism implies that an anatomically normal individual feels that he or she is actually a member of the opposite sex. Treatment usually includes real-life experience along with hormone therapy and sex reassignment surgery. Voice modification surgery may be necessary, as pass ability in general is still in a large extent dependent on the aspects of voice in transsexual people. Often male-to-female patients report being addressed in telephone conversations as their genetic gender, which is experienced as a disability. The purpose of this study was to evaluate the impact of voice on the quality of life in transsexuals.

In order to detect the disability caused by a voice disorder, the validated assessment method the Voice Handicap Inventory (VHI) was used. An additional question about the way patients were addressed in a telephone conversation was added.

As part of a study describing general health in transsexual persons, done at the Ghent University Hospital Belgium, a total of 48 patients were evaluated. In female-to-male transsexuals the median scores were very low, suggesting testosterone treatment led to an acceptable voice alteration. A higher serum LH level was significantly correlated with higher total, functional and emotional VHI scores. In male-to-female transsexuals the scores were significantly higher than those of the female-to-male transsexuals, but still there was no indication of a real disability/handicap. The extra telephone question was scored higher suggesting male-to-female transsexuals did experience a disability caused by their voice. From this study it is concluded that the VHI values did not demonstrate a handicapping effect.     

The influence of sex hormones on functional cerebral asymmetries in postmenopausal women

Studies investigating changes in functional cerebral asymmetries (FCAs) with hormonal fluctuations during the menstrual cycle in young women have led to controversial hypotheses about an influence of estrogen (E) and/or progesterone (P) on FCAs. Based on methodical, but also on principal problems in deriving conclusions about hormone effects from correlational designs, the present study investigated hemispheric asymmetries in postmenopausal women, who received hormone replacement either with E alone (E group, n = 32), an E–P combination (E–P group, n = 29) or no hormone substitution (control group, n = 31). Speed and accuracy of responses to a word- and a face decision task, both presented laterally by means of the visual half field technique, were assessed. The control group showed the typical pattern of hemispheric asymmetry with more correct responses to verbal stimuli presented in the right visual field (RVF) and to face stimuli presented in the left visual field (LVF). A hormone-effect was demonstrable only for the verbal task, in which the E group showed an enhanced performance of the right hemisphere (LVF). The E–P group showed no significant differences to the control group or the E group. The results suggest a role of E in the modulation of FCAs at least with regard to verbal processing.     

In judo,Randori (free fight) and Kata (highly ritualized fight) differentially change plasma cortisol,testosterone, and interleukin levels in male participants

Two forms of competitive encounters namely Randori (free fight) and Kata (highly ritualized fight) were studied in 22 professional male judo fighters. The dyadic, symmetrical (in terms of body weight and fighting ability) encounters were videotaped to assess relationships between agonistic behavior and individual variations in plasma levels of testosterone (T), cortisol (C) and interleukins (IL‐6 and IL‐1β) measured before and after the competition. Unremarkably, winners showed longer attack but devoted less time to defensive behaviors when compared to losers. T increased only during Randori but the individual pre‐ and post‐competition T levels recorded in such fights were strongly correlated with the corresponding measures in the Kata for the same individuals. Interestingly, the pre‐ and post‐Randori competition T levels were higher in losers than in winners and T variations positively correlated with the frequencies of attacks and with the duration of defensive postures. The T response shows individual variation and seems to reflect evaluation of the likelihood of winning or losing. Both Randori and Kata induced a marked C increase, although the pre‐ and post‐Randori hormonal titers were higher than those found for the Kata. IL‐6 significantly increased between the pre‐ and the post‐Randori competition, but no such changes occurred during the Kata. No correlations were found between individual pre‐ and post‐competition C and IL‐6 and IL‐1β levels in either Randori or Kata. This suggests that C and cytokine release are unrelated to emotional or cognitive perception of the possible outcome of fighting but are a consequence of general motor activity. Martial arts appear to provide good human models to understand: (a) the relationships between conflict, hormones and the immune system and (b) the relationships between mood and physiological responses to competitive aggression. Aggr. Behav. 32:1–9, 2006. © 2006 Wiley‐Liss, Inc.     

A Sex Difference on a Novel Spatial Working Memory Task in Humans

Neurophysiological and behavioral evidence suggests that the prefrontal cortex (PFC) may be sexually differentiated in nonhuman primates. The present study examined whether there are sex differences in working memory in humans that might reflect sexual differentiation of human PFC. Male and female undergraduates were administered a novel multitrial spatial working memory task (SPWM) and a verbal working memory task. In three experiments, females committed significantly fewer working memory errors and took significantly less time to reach criterion than males on the SPWM task. The female advantage was not accounted for by differences in general intellectual ability, attention, perceptual speed, incidental memory, or speed of verbal access. In Study 3, a sex difference was also observed on a measure of verbal working memory. The findings suggest that some prefrontal functions may be sexually differentiated in humans.