每日一题_2023.09.01

An endocrine research laboratory is investigating the regulation of the hypothalamic- pituitary axis through pharmacologic means in the brains of chimpanzees. They find that administering extremely high doses of chlorpromazine causes parkinsonism, amenorrhea, lack of positive reward trainability, and decreased cognitive ability test scores in female chimpanzees. These findings allow them to identify specific neural tracts in the brain that are interrupted by chlorpromazine. Interruption of what neural tract is responsible for the amenorrhea observed in the studied chimpanzees?

一个内分泌研究实验室正在研究黑猩猩大脑中通过药物手段对下丘脑-垂体轴的调节。他们发现，给雌性黑猩猩服用极高剂量的氯丙嗪会导致帕金森症、闭经、缺乏正向奖励可训练性以及认知能力测试分数下降。这些发现使他们能够识别大脑中被氯丙嗪中断的特定神经束。在被研究的黑猩猩中，什么神经束的中断导致了闭经?

(A) Mesocortical tract中皮质束

(B) Mesolimbic tract中脑边缘系统

(C) Nigrostriatal tract黑质纹状体束

(D) Tuberoinfundibular tract 结节漏斗束

答案解析：

氯丙嗪是一种典型的抗精神病药，作为D2受体拮抗剂在列出的四个主要多巴胺束中发挥作用。在正常的下丘脑-肾上腺轴中，除泌乳素外，所有激素的释放都受到激素的增加或减少的调节。催乳素分泌由多巴胺能神经元控制的负反馈系统调节。相反的关系可见，多巴胺的增加导致催乳素分泌的减少，反之亦然。了解典型的抗精神病药作为D2受体拮抗剂在结节漏斗束引起高泌乳素血症是回答这个问题的第一步。结合高泌乳素血症导致月经异常和/或闭经的事实，我们选择结节漏斗束作为中断的束，通过D2受体拮抗剂来解除催乳素的抑制。

正确答案：D