Elevation and reduction of plasma tryptophan and their effects on aggression and perceptual sensitivity in normal males

Data from experimental animals suggest that 5-hydroxytryptamine (5HT) may have an inhibitory effect on aggression, while clinical studies have found a correlation between pathological aggression and low brain 5HT. To investigate this relationship further we used amino acid mixtures designed to raise or lower the levels of the 5HT precursor, tryptophan. Normal male subjects were given tryptophan-depleted, balanced, or tryptophan-supplemented ammo acid mixtures and tested for aggression 5 hours later. The balanced amino acid mixture served as a control for the tryptophan depletion and supplementation. Testing for aggression was done using the Buss paradigm in which subjects deliver electric shocks to a (nonexistent) partner in response to stimulus tones. Duration and intensity of shock delivered were the measures of aggression, while responsivity to the stimulus tones was the measure of perceptual sensitivity. Neither tryptophan supplementation nor tryptophan depletion had any effect on these measures of aggression or perceptual sensitivity. We conclude that raising or lowering the synthesis of brain 5HT through alterations in tryptophan availability does not influence aggression in normal males as measured by the Buss task.     

UFO和声称的绑架事件调查(二)——真相与误导

上世纪50年代,UFO目击者和加入这个事件的渲染者使事件急剧升温。1950年,弗朗克·斯库利(Frank Scully)发表了一本引起轰动的书,叫《追踪飞碟》。书中声称,一个飞碟坠毁在新墨西哥的阿兹特克东部的偏僻的高原沙漠上,飞碟的直径为99英尺,里面有16个外星人的尸体。斯库利自己并没有看见这个场景,仅仅是听别人说的。2年以后,发现这个故事是个骗局。关于飞碟坠毁的另一个故事也是发生在新墨西哥,地点是位于罗斯威尔西北部的75英里一处空军基地。据猜测,这次坠毁发生在1947年的7月,由此引发了一系列的事件和争论,并延续至今。坠毁是不容争论的,…