Then, altruists could choose each other in order to retain benefits through mutual cooperation. Previous research has shown that individuals can predict the degree of altruistic behavior

of strangers by reading signs of emotions evoked in significant social decisions. However, the identification of benevolent emotional states is no guarantee of the existence of permanent altruistic traits, though permanent traits are the preferable criterion AC220 ic50 for selection of good interaction partners. In this study, we tested whether individuals are able to identify altruistic traits. Judges watched 20-s silent video clips of unacquainted target persons and were asked to estimate the behavior of these target persons in a money-sharing task. As the videotapes of the target persons had been recorded in a setting unrelated to altruistic behavior, the judges could not base their estimates on situational cues related to the money-sharing

task but instead had to draw on stable signals of altruism. Estimates were significantly better than chance, indicating that individuals can identify permanent altruistic traits in others. As this mechanism raises opportunities for selective interactions between altruists, our findings are discussed with respect to their relevance for explaining Mocetinostat manufacturer the evolution of altruism through assortment. (C) 2010 Elsevier Inc. All rights reserved.”
“BACKGROUND: The analgesic action of botulinum neurotoxin type A (BoNTA) has been linked to the blockade of peripheral release of neuropeptides and neurotransmitters in animal models; however, there is no direct evidence of this in humans. OBJECTIVES: To investigate the effect of BoNTA on glutamate release in humans, using an experimental model of pain and sensitization

provoked by capsaicin plus mild heat. METHODS: Twelve healthy volunteers (six men, six women) were pre-treated with BoNTA (10 U) on the volar forearm and with a saline control on the contralateral side. Dermal microdialysis was applied one week later to collect interstitial samples before and after the application of a capsaicin patch (8%) plus MEK inhibitor side effects mild heat (40 degrees C/60 min) to provoke glutamate release, pain and vasodilation. Samples were collected every hour for 3 h using linear microdialysis probes (10 mm, 100 kD). Dialysate was analyzed for glutamate concentration. Pain intensity and skin vasomotor reactions (temperature and blood flow changes) were also recorded. RESULTS: BoNTA significantly reduced glutamate release compared with saline (P smaller than 0.05). The provoked pain intensity was lower in the BoNTA-pretreated arm (P smaller than 0.01). The reduction in pain scores was not correlated with glutamate level. Cutaneous blood flow (P smaller than 0.05), but not cutaneous temperature (P bigger than = 0.05), was significantly reduced by BoNTA. There was a correlation between glutamate level and skin blood flow (r=0.58/P smaller than 0.05) but not skin temperature (P bigger than = 0.05).