捕食风险对小型哺乳动物行为、神经和内分泌的影响

长期进化过程中，猎物形成了对捕食者先天的敏感性。捕食风险对小型哺乳动物的影响主要包括行为的改变、神经环路的激活和内分泌的变化。行为的改变包括抑制运动活动、降低非防御行为以及改变生活环境。一些研究用c-fos免疫组化的方法测定了大鼠在暴露于猫的气味后大脑被激活的区域，主要包括中间杏仁核、下丘脑腹内侧区、背内侧区、前乳头状核和导水管周围灰质（periaqueductal gray）。猎物对捕食应激的反应还表现在一些内分泌指标的改变，一些激素如皮质酮（Corticoserone，CORT）和促肾上腺皮质激素（Adrenocorticotropic hormone，ACTH）的含量会显著的增加，同时在一些雄性动物中，睾丸激素的含量会有所降低。捕食者和猎物的关系近年来已经成为很多学科研究的有用工具。

Effects of Predation risk on Small Mammals

Prey species reveals senstivity towards their predators' odor in the long evolution process. The effects of predation risk in small mammals are mainly include: changes of behavior, activation of the neural circuit and variation of the endocrine. Field and laboratory studies show that predator odors have distinctive behavioral effects which include:inhibition of activity, suppression of non-defensive behaviors and shift of habitats or secure locations where such odors are not present. C-fos immunohistochemistry indicates that predator odor selectively activates a defensive behavior circuit involving the medial amygdala, ventromedial and dorsomedial hypothalamus, dorsal premammillary nucleus and the periaqueductal gray. Predator odors can powerfully affect the endocrine system including a suppression of testosterone and increased levels of stress hormones such as corticosterone and ACTH. The relation between predator and preys are useful tools for many different scientific disciplines.