Blanchard D Caroline, Canteras Newton S, Markham Chris M, Pentkowski Nathan S, Blanchard Robert J
Pacific Biomedical Research Center, University of Hawaii, Honolulu, HI 96822, USA.
Neurosci Biobehav Rev. 2005;29(8):1243-53. doi: 10.1016/j.neubiorev.2005.04.019. Epub 2005 Aug 9.
Exposure of rats to a cat elicits Fos activity in a number of brain areas or structures. Based on hodological relationships of these, Canteras has proposed a medial hypothalamic defense system, with input from several forebrain sites. Both electrolytic and neurotoxic lesions of the dorsal premammillary nucleus, which shows the strongest Fos response to cat exposure, produce striking decrements in a number of defensive behaviors to a cat or to cat odor stimuli, but do not have a major effect on either postshock freezing, or responsivity to the odor of a female in estrus. Neurotoxic lesions of the medial amygdala produce decrements in defensiveness to predator stimuli, particularly odor stimuli, that are consistent with a view of this structure as involved with allomonal cues. While dorsal hippocampal lesions had little effect on responsivity to predator stimuli, neurotoxic lesions of the ventral hippocampus reduced freezing and enhanced a variety of nondefensive behaviors to both cat odor and footshock, with similar reductions in defensiveness during context conditioning tests for cat odor, cat exposure and footshock. These results support the view that the dorsal premammillary nucleus is strongly and selectively involved in control of responsivity to predator stimuli. Structures with important input into the medial hypothalamic defense system appear also to be functionally involved with antipredator defensive behaviors, and these lesion studies may suggest specific hypotheses as to the particular defense functions of different areas.
让大鼠暴露于猫的环境中会在多个脑区或结构中引发Fos活性。基于这些脑区的神经传导关系，坎特拉提出了一种内侧下丘脑防御系统，其输入来自几个前脑部位。背侧乳头前核对猫暴露表现出最强的Fos反应，对其进行电解损伤和神经毒性损伤，都会使对猫或猫气味刺激的多种防御行为显著减少，但对电击后僵住反应或对处于发情期雌性气味的反应性没有重大影响。内侧杏仁核的神经毒性损伤会使对捕食者刺激（尤其是气味刺激）的防御性降低，这与该结构参与异种信号的观点一致。虽然背侧海马损伤对捕食者刺激的反应性影响不大，但腹侧海马的神经毒性损伤会减少僵住反应，并增强对猫气味和电击的多种非防御行为，在针对猫气味、猫暴露和电击的情境条件测试中，防御性也有类似程度的降低。这些结果支持了这样一种观点，即背侧乳头前核强烈且选择性地参与对捕食者刺激反应性的控制。向内侧下丘脑防御系统输入重要信息的结构似乎在功能上也与反捕食者防御行为有关，这些损伤研究可能会就不同区域的特定防御功能提出具体假设。
