Adamec R E
Department of Psychology, Memorial University, St. John's, Newfoundland, Canada.
Physiol Behav. 1991 Mar;49(3):455-64. doi: 10.1016/0031-9384(91)90264-o.
In Experiment I, neurosensory responses from three limbic areas in the cat brain were recorded when cats of differing defensive temperamental traits were exposed to species characteristic threat. The cats investigated were more or less defensive in response to rats and conspecific threat howls. The behavioral disposition of these cats was stable over retest periods of more than one year. It was found that during visual inspection of rats, more defensive cats displayed greater neural activity in the amygdala and the ventromedial hypothalamus than less defensive cats, who showed no change over baseline. Neurosensory response of the amygdala to conspecific threat howls was also found to be greater in more defensive cats. In contrast, there was no neural response to threat howls in the hypothalamus. Neurosensory response to mice was different from the response to rats and threat howls. Visual inspection of the mouse was associated with a decrease in activity in the amygdalas of more defensive cats. Finally, response of the ventral hippocampus was unspecific, appearing to signal only a change in the stimulus environment. The increase in hypothalamic neural activity in response to rats in more defensive cats appeared to be driven by a potentiated output from the amygdala, since the ratio of hypothalamic to amygdala neurosensory response to rats was greater than one in more defensive cats, but equal to one in less defensive cats. Output of the amygdala was directly investigated using evoked potential techniques in Experiment II. Potentials evoked in the hypothalamus by amygdala stimulation were larger in more defensive cats. Size of the hypothalamic potential was highly correlated with the ratio of hypothalamic to amygdala neurosensory response (ratio response) to rats. Removing the effects of size of the hypothalamic evoked potential from the ratio response by analysis of covariance eliminated the difference between more and less defensive cats in ratio response to rats. The significance of these findings for the physiological bases of defensive response to threat and of temperamental traits are discussed.
在实验一中，当具有不同防御性气质特征的猫暴露于物种特征性威胁时，记录了猫脑三个边缘区域的神经感觉反应。所研究的猫对大鼠和同种威胁叫声或多或少具有防御性。这些猫的行为倾向在一年多的重新测试期内保持稳定。结果发现，在对大鼠进行视觉检查期间，防御性较强的猫在杏仁核和腹内侧下丘脑的神经活动比防御性较弱的猫更强，而防御性较弱的猫与基线相比没有变化。还发现，防御性较强的猫的杏仁核对同种威胁叫声的神经感觉反应也更大。相比之下，下丘脑对威胁叫声没有神经反应。对小鼠的神经感觉反应与对大鼠和威胁叫声的反应不同。对小鼠的视觉检查与防御性较强的猫的杏仁核活动减少有关。最后，腹侧海马体的反应是非特异性的，似乎仅表明刺激环境的变化。防御性较强的猫对大鼠反应时下丘脑神经活动的增加似乎是由杏仁核增强的输出驱动的，因为防御性较强的猫下丘脑与杏仁核对大鼠的神经感觉反应之比大于1，而防御性较弱的猫则等于1。在实验二中使用诱发电位技术直接研究了杏仁核的输出。杏仁核刺激在下丘脑诱发的电位在防御性较强的猫中更大。下丘脑电位的大小与下丘脑与杏仁核对大鼠的神经感觉反应之比（比率反应）高度相关。通过协方差分析从比率反应中消除下丘脑诱发电位大小的影响后，消除了防御性较强和较弱的猫在对大鼠的比率反应上的差异。讨论了这些发现对威胁防御反应和气质特征生理基础的意义。
