Game location moderates the relationship between anticipatory testosterone changes and athletic performance.

The authors examined the extent to which changes in testosterone concentrations before competition would be associated with performance among elite male hockey players. Saliva samples were collected on 2 noncompetition days (baseline) and before 2 playoff games (1 home game, 1 away game). Individual performance was assessed by the coaching staff after each game. Results indicated that changes in testosterone before competition predicted performance, but this effect was influenced by game location. Unexpectedly, the authors found a significant negative relationship between a rise in testosterone and performance for the away game and a nonsignificant positive relationship for the home game. These findings indicate that game location should be considered in studies examining the neuroendocrine correlates of athletic competition.

Comparison of saliva collection methods in children with high-functioning autism spectrum disorders: acceptability and recovery of cortisol.

This study compared cortisol concentrations yielded using three saliva collection methods (passive drool, salivette, and sorbette) in both in vitro and in vivo conditions, as well as method acceptability for a sample of children (n = 39) with High Functioning Autism Spectrum Disorders. No cortisol concentration differences were observed between passive and sorbette samples obtained in vitro or in vivo. The salivette derived concentration was lower than the other two methods for the in vitro derived comparisons but did not differ from the other methods when collected in vivo. Cross-day comparison for the salivettes was also found to differ significantly, whereas the cross-day comparisons did not differ for the passive method or the sorbette method. Overall, passive drool and sorbettes were found to produce similar and stable readings of cortisol, whereas the salivette yielded unstable and variable concentrations. Ratings suggested that the children generally perceived all methods as acceptable.

Watching a previous victory produces an increase in testosterone among elite hockey players.

Previous research indicates that testosterone concentrations are highly responsive to human competitive interactions and that winners have elevated testosterone concentrations relative to losers. Also, there is some evidence that simply observing others compete can have a similar effect on the endocrine system. Here, in two studies, we examined the extent to which elite male hockey players would demonstrate an increase in testosterone concentrations after watching themselves engaged in a previous successful competitive interaction. Results indicated that watching a previous victory produced a significant increase in testosterone concentrations (42-44% increase), whereas watching a previous defeat or a neutral video did not produce a significant change in testosterone (17% and 6%, respectively). Given that natural fluctuations in testosterone have been shown to influence future competitive and aggressive behaviours, the current studies may have important practical implications for individuals involved in competitive sports.

Testosterone responses to competition predict future aggressive behaviour at a cost to reward in men.

The extent to which trait factors (baseline testosterone concentrations, trait dominance) and state factors (change in social status, change in testosterone concentrations) would predict reactive aggression in a subsequent task that involved provocation was examined in 99 participants (39 men and 60 women). Participants first competed in same-sex dyads on a Number Tracing Task for which the outcome (win or loss) was rigged. After the competition, participants performed the Point Subtraction Aggression Paradigm (PSAP), a behavioural measure of reactive aggression against an opponent (actually a computer program). Trait dominance predicted baseline testosterone in men, but not women, and men made more aggressive responses than did women. Baseline testosterone concentrations did not predict aggressive behaviour in either men or women. Winners and losers did not differ in competition-induced change in testosterone. However, change in testosterone concentrations predicted aggressive responses in the PSAP for men in the loss condition, and aggressive responses were made at a cost to obtaining reward points. For men in the win condition, aggressive responses were predicted by an interaction between trait dominance and change in testosterone concentrations. These findings suggest that situational changes in testosterone concentrations modulate future aggressive behaviour in men.

Effect of social familiarity on salivary cortisol and self-reports of social anxiety and stress in children with high functioning autism spectrum disorders.

This study examined the effect of social familiarity on salivary cortisol and social anxiety/stress for a sample of children with high-functioning autism spectrum disorders. The relationship between self-reported social anxiety/stress and salivary cortisol was also examined. Participants interacted with a familiar peer on one occasion and an unfamiliar peer on another occasion. Data were collected using salivary cortisol and a scale measuring subjective stress. Results indicated a significant condition by order interaction for salivary cortisol levels, while self-rated stress did not differ significantly across situations. A mild-moderate correlation was found between self-reported distress and salivary cortisol within each condition. Examination of self-rated distress vs. cortisol scatter plots suggested a more complex relationship than the correlation coefficient could adequately convey.

Pre-competition hormonal and psychological levels of elite hockey players: relationship to the "home advantage".

The home advantage is a robust phenomenon that occurs in the world of amateur and professional sport. Athletic teams have been shown to win significantly more games in their home venue as compared to their opponents' venue. Studies have suggested that the home advantage may be related to familiarity with the facility, increased crowd density and even pre-competition hormonal levels. The present study investigated pre-competition physiological and psychological states of elite hockey players in the home and away venues. Physiological measures included salivary cortisol and testosterone, which were assessed using enzyme immunoassays. In addition, pre-competition psychological states were assessed using the Competitive State Anxiety Inventory-2. Physiological measures indicated that the players had significantly higher pre-game testosterone when playing in their home venue as compared to their opponents' venue (t(13)=2.29, p=0.04); however, this difference was not due to a pre-game rise in testosterone while competing at home. Furthermore, players showed a trend toward higher pre-game cortisol when playing in their home venue (t(13)=1.96, p=0.07). Psychological measures indicated that players were more self-confident when playing in their home venue (t(13)=2.8, p=0.008) and also had higher somatic (t(13)=2.3, p=0.02) and cognitive anxiety (t(13)=1.87, p=0.04) when playing in their opponents' venue. The present study supports the notion that there are differences in pre-competition hormonal and psychological states that may play a key role in the "home advantage".

Neuronal nitric oxide synthase and gonadal steroid interaction in the MPOA of male rats: co-localization and testosterone-induced restoration of copulation and nNOS-immunoreactivity.

Neuronal nitric oxide synthase (nNOS) in the medial preoptic area (MPOA) has been implicated in various physiological functions, including male rat copulation. Based on their apparent sensitivity to gonadal steroid manipulation, we hypothesized that nNOS cells contain steroid receptors, and the testosterone-induced restoration of nNOS-immunoreactivity in castrates should accompany the restoration of copulation. In Experiment 1, we investigated co-localization of nNOS with the androgen receptor (AR) and the estrogen receptor alpha (ERalpha) using immunocytochemistry. We found regionally specific co-localizations of nNOS-AR and nNOS-ERalpha. In Experiment 2, we investigated the relationship between MPOA nNOS-immunoreactivity (ir) and copulatory measures in the testosterone-induced restoration paradigm in castrates. The restoration of various copulatory measures was accompanied by an increase in optical density of nNOS-ir, but not in the number of nNOS-ir cells. These data provide additional evidence supporting the role of MPOA nitric oxide in male rat copulation.

Effects of testosterone metabolites on copulation, medial preoptic dopamine, and NOS-immunoreactivity in castrated male rats.

The medial preoptic area (MPOA) is an important integrative site for male sexual behavior. Dopamine (DA) is released in the MPOA of male rats shortly before and during copulation. In a previous study, we identified 17beta-estradiol (E(2)) as the metabolite of testosterone (T) that maintains MPOA basal extracellular DA levels. However, the presence of dihydrotestosterone (DHT), an androgenic metabolite of T, is required for the female-induced increase in MPOA DA observed during copulation. Recently, we reported that assays of MPOA tissue DA content showed that castrates actually had more stored DA than did gonadally intact males. Therefore, the reduction in extracellular levels in castrates was not due to decreased availability of DA; most likely it was due to decreased release. Furthermore, T upregulates neuronal nitric oxide synthase (nNOS) in the MPOA. NO has been implicated in the regulation of DA release in the MPOA. It is not known, however, which metabolite(s) of T regulate(s) tissue stores of DA and/or nNOS in the MPOA of male rats. The present experiments were designed to test the following: (1) whether E(2), DHT, or the combination of the two influences MPOA DA tissue levels, an indication of stored DA, in male rat castrates; and (2) whether E(2), DHT, or the combination of the two influences NOS-ir in the MPOA of castrated male rats. The results indicate that E(2) up-regulates nNOS-ir in the MPOA and maintains tissue content of DA at levels similar to those in T-treated rats. DHT did not influence nNOS-ir, while attenuating the effect of castration on tissue DA content.

Effects of testosterone metabolites on copulation and medial preoptic dopamine release in castrated male rats.

The medial preoptic area (MPOA) is an important integrative site for male sexual behavior. Dopamine (DA) is released in the MPOA of male rats shortly before and during copulation. The recent presence of testosterone (T) may be necessary for this precopulatory increase in release. Previously, the postcastration loss of copulatory ability mirrored the loss of the DA response to an estrous female, and the restoration of copulation with exogenous T was concurrent with the reemergence of this DA response. The present study investigated the effectiveness of the two major metabolites of T in maintaining copulation and basal and female-stimulated DA levels. Adult male rats were castrated and received daily injections of estradiol benzoate (EB), dihydrotestosterone benzoate (DHTB), EB + DHTB, testosterone propionate (TP), or oil vehicle for 3 weeks. Microdialysis samples were collected from the MPOA during baseline conditions, exposure to an estrous female behind a barrier, and copulation testing. EB + DHTB- and TP-treated animals had normal basal DA levels and showed a precopulatory DA response, and most copulated normally. EB-treated castrates had high basal DA levels, but failed to show a female-stimulated increase; most intromitted, but none ejaculated. DHTB- and oil-treated groups had low basal levels of extracellular DA that did not increase during copulation testing; most failed to mount and none ejaculated. These results suggest that E maintains normal basal levels of extracellular DA in the MPOA, which are sufficient for suboptimal copulation, but that androgen is required for the female-stimulated increase in DA release and for facilitation of ejaculation.