Implicit power motivation moderates men's testosterone responses to imagined and real dominance success

This study tested the hypothesis that implicit power motivation moderates individuals' testosterone responses to the anticipated success in and actual outcome of a dominance contest. Salivary testosterone levels were assessed in 42 male students at the beginning of the study, after they had imagined a success in an ensuing power contest, and immediately after the contest had taken place. Contest outcome (winning or losing against a competitor on a speed-based task) was varied experimentally. Participants' power motive was assessed with a picture-story exercise, in which an assertive, personalized (p Power) component was distinguished from an altruistic, socialized (s Power) component. In contrast to all other participants, individuals high only in p Power (a) had elevated testosterone after imagining a success in a subsequent dominance contest and (b) continued to have high testosterone levels after actually winning, but not after losing, the contest.     

Salivary cortisol changes in humans after winning or losing a dominance contest depend on implicit power motivation

In two studies, one with an all-male German sample and the other with a mixed-sex U.S. sample, subjects competed in pairs on reaction time-based cognitive tasks. Participants were not aware that contest outcome was experimentally varied. In both studies, implicit power motivation, defined as the non-conscious need to dominate or have impact on others, predicted changes in salivary cortisol from before to after the contest. Increased cortisol post-contest was associated with high levels of power motivation among losers but with low levels of power motivation among winners, suggesting that a dominance success is stressful for low-power individuals, whereas a social defeat is stressful for high-power individuals. These results emerged only in participants tested in the afternoon, possibly because of greater variability in cortisol in the morning due to the rapid decline after the morning peak. These studies add to the evidence that individual differences greatly influence whether a social stressor like losing a contest activates the HPA axis in humans.     

Basal and dynamic relationships between implicit power motivation and estradiol in women

This study investigated basal and reciprocal relationships between implicit power motivation (n Power), a preference for having impact and dominance over others, and both salivary estradiol and testosterone in women. 49 participants completed the Picture Story Exercise, a measure of n Power. During a laboratory contest, participants competed in pairs on a cognitive task and contest outcome (win vs. loss) was experimentally varied. Estradiol and testosterone levels were determined in saliva samples collected at baseline and several times post-contest, including 1 day post-contest. n Power was positively associated with basal estradiol concentrations. The positive correlation between n Power and basal estradiol was stronger in single women, women not taking oral contraceptives, or in women with low-CV estradiol samples than in the overall sample of women. Women's estradiol responses to a dominance contest were influenced by the interaction of n Power and contest outcome: estradiol increased in power-motivated winners but decreased in power-motivated losers. For power-motivated winners, elevated levels of estradiol were still present the day after the contest. Lastly, n Power and estradiol did not correlate with self-reported dominance and correlated negatively with self-reported aggression. Self-reported dominance and aggression did not predict estradiol changes as a function of contest outcome. Overall, n Power did not predict basal testosterone levels or testosterone changes as a function of dominance contest outcome.     

Disorders in memory and learning in offspring of alcoholized female rats,and a possibility for correction of these changes

We studied the effect of alcohol intoxication of albino female rats on the process of learning and memory of their adult (two-month-old) offspring and also a possibility for correction of the observed changes using dolivin. During pregnancy and lactation, female rat of the experimental group obtained 15% solution of ethanol instead of water. To estimate the successfulness of spatial learning of their offspring, we used a multiway elevated labyrinth; the level of consolidation of memory traces was estimated using a passive avoidance test in a chamber with dark and illuminated sections. In the tested offspring rats, prenatal exposure to ethanol induced dramatic drops in the indices of both the above tests. The use of dolivin simultaneously with ethanol exposure allowed us to demonstrate the clear protective properties of this complex preparation containing such antioxidants as hypoxen and vitamin E: disorders in behavior of the offspring of alcoholized females were smoothed significantly. Neirofiziologiya/Neurophysiology, Vol. 40, No. 2, pp. 130–136, March–April, 2008.     

Molecular changes in the intermediate medial mesopallium after a one trial avoidance learning in immature and mature chickens

Because brain maturation in chickens is protracted and occurs well after the major developmental period of synaptogenesis, chicken forebrain is suitable to investigate whether the molecular mechanisms underlying memory consolidation are different in immature and mature animals. We have used antibodies and western blotting to analyze subcellular fractions from the intermediate medial mesopallium region of 14-day and 8-week chicken forebrain prepared 0, 45, and 120 min after learning a discriminative taste avoidance task. At both ages learning induced changes in the phosphorylation of the glutamate receptor subunit 1 at Ser831, the levels of calcium-calmodulin stimulated/dependent protein kinase II and the phosphorylation of calcium-calmodulin stimulated/dependent protein kinase II at Thr286 were observed only in the fraction enriched in post-synaptic densities. The changes were of the same type at the two ages but occurred faster in mature animals. The changes in extracellular signal regulated kinase and phosphorylated-extracellular signal regulated kinase were more complex with different subcellular fractions showing different patterns of change at the two ages. These results imply that the molecular changes induced by learning a behavioral task are faster in mature than immature brain and may involve a different balance of intracellular signaling pathways.