Department of Biology, Boston University, Boston, MA 02215, United States.
Physiol Behav. 2012 Jan 18;105(2):554-9. doi: 10.1016/j.physbeh.2011.09.014. Epub 2011 Sep 17.
Previous research showed that axonal inputs to both anterior and posterior subdivisions of the medial amygdala from the main and accessory olfactory bulbs of female mice, respectively, process volatile and non-volatile pheromonal signals from male conspecifics. In the present study we found that bilateral electrolytic lesions that included posterior portions, but not the anterior subdivision alone of the medial amygdala (Me) blocked the preference of estrous female mice to investigate volatile urinary odors from testes-intact vs. castrated males. Similar results were obtained in separate tests in which nasal contact with urinary stimuli was permitted. In addition, total time investigating volatile urinary stimuli was reduced in subjects with posterior Me lesions. Subjects were able to discriminate volatile urinary odors from testes-intact vs. castrated male mice, suggesting that this disruption of odor preference did not result from the inability of females given amygdaloid lesions to discriminate these male urinary odors. Bilateral lesions of the Me that were either restricted to the anterior or posterior subdivisions, or included areas of both regions, caused significant reductions in the display of lordosis behavior in estrous female mice. Our results suggest that the Me is a critical segment of the olfactory circuit that controls both mate recognition and mating behavior in the female mouse.
先前的研究表明，来自雌性小鼠主嗅球和辅助嗅球的轴突输入分别投射到杏仁核内侧的前、后两个亚区，以处理来自雄性同种动物的挥发性和非挥发性信息素信号。在本研究中，我们发现双侧电解损伤包括杏仁核内侧的后部，但不包括前部亚区（Me），会阻断发情期雌性小鼠对来自未去势雄性和去势雄性的尿液挥发气味的偏好。在允许鼻腔接触尿液刺激的单独测试中也得到了类似的结果。此外，Me 后部损伤的实验对象对挥发性尿液刺激的总探查时间减少。这些实验对象能够区分来自未去势雄性和去势雄性小鼠的尿液挥发气味，这表明这种气味偏好的破坏不是由于接受杏仁核损伤的雌性动物无法区分这些雄性尿液气味造成的。Me 的双侧损伤仅限于前部或后部亚区，或包括两个区域的区域，都会导致发情期雌性小鼠表现出明显的弓背行为减少。我们的结果表明，Me 是嗅觉回路的一个关键部分，它控制着雌性小鼠的配偶识别和交配行为。
