Hubbard D T, Blanchard D C, Yang M, Markham C M, Gervacio A, Chun-I L, Blanchard R J
Department of Psychology, University of Hawaii, 2430 Campus Road, Honolulu, HI 96822-2216, USA.
Physiol Behav. 2004 Jan;80(4):525-30. doi: 10.1016/j.physbeh.2003.10.006.
Laboratory rats show a range of defensive behaviors, including freezing, avoidance, and risk assessment upon exposure to cat odor, an unconditioned but highly effective threat stimulus. This study examined defensive behaviors, and the rapid conditioning to context plus cue, of these behaviors, in 18-, 26-, and 38-day-old male and female rats exposed to cat odor. Rats were placed individually in a runway with a cloth covered (control or saturated with cat fur/skin odor) block for a 10-min trial. On the following day, a similar trial involved an odorless block. On the odor exposure day, rats of all ages showed less contact with the odor block than with the control block. The 26- and 38-day-old rats, but not the 18-day-old rats, also showed locomotor suppression, more avoidance of the area where the odor block was located, and more risk assessment than no-odor controls. On a test of conditioned behavior 24 h following exposure, 26- and 38-day-old rats exhibited defensive behavior including avoidance and reduction of locomotion while 18-day-old pups did not.
实验大鼠在接触猫的气味（一种无条件但高效的威胁刺激）时会表现出一系列防御行为，包括僵住、回避和风险评估。本研究考察了18日龄、26日龄和38日龄的雄性和雌性大鼠在接触猫的气味时的防御行为，以及这些行为对环境加线索的快速条件反射。将大鼠单独放置在一条跑道上，跑道上有一个用布覆盖的（对照或浸有猫毛/皮肤气味的）方块，进行10分钟的试验。第二天，进行类似的试验，使用无味方块。在接触气味的当天，所有年龄段的大鼠与气味方块的接触都比与对照方块的接触少。26日龄和38日龄的大鼠，而不是18日龄的大鼠，还表现出运动抑制，更多地回避气味方块所在区域，并且比无气味对照组有更多的风险评估行为。在接触气味24小时后的条件行为测试中，26日龄和38日龄的大鼠表现出包括回避和运动减少在内的防御行为，而18日龄的幼鼠则没有。
