Rosenblatt J S, Mayer A D, Giordano A L
Institute of Animal Behavior, Rutgers State University, Newark, New Jersey 07102.
Psychoneuroendocrinology. 1988;13(1-2):29-46. doi: 10.1016/0306-4530(88)90005-4.
This article reviews the current state of our knowledge about the hormonal basis of maternal behavior in the rat. Considered are the ovarian hormones estrogen and progesterone, the pituitary hormones beta-endorphin and prolactin, and the hormone oxytocin, secreted by several hypothalamic nuclei and associated brain regions. The hormones of pregnancy, estrogen and progesterone, prime the female to respond to a terminal rise in estrogen that stimulates a high level of maternal responsiveness even before parturition begins. Studies on the role of prolactin, using hypophysectomy, prolactin release blockers and anterior pituitary and prolactin replacement, indicate that prolactin is required for the ovarian hormones to be effective in stimulating maternal behavior. During the latter half of pregnancy, placental lactogen may displace prolactin in this role. Although prolactin serves as a chronic stimulus for maternal behavior, it also may act over a short period. Oxytocin stimulates maternal behavior in a specific strain of rat, but not in other strains, and only when administered introcerebroventricularly (ICV) in estrogen-primed females. The decline in the high brain levels of beta-endorphin around parturition has been proposed as a requirement for the onset of maternal behavior; morphine blocks the onset of maternal behavior and disrupts ongoing maternal behavior and maternal aggression in lactating females. However, blocking beta-endorphin action at parturition interferes with pup cleaning and eating of the placenta as well.
本文综述了我们目前对大鼠母性行为激素基础的认识状况。所考虑的激素包括卵巢激素雌激素和孕酮、垂体激素β-内啡肽和催乳素，以及由几个下丘脑核团和相关脑区分泌的激素催产素。妊娠激素雌激素和孕酮使雌性做好准备，以应对雌激素的最终升高，这种升高甚至在分娩开始前就刺激了高水平的母性反应。利用垂体切除、催乳素释放阻滞剂以及垂体前叶和催乳素替代物对催乳素作用的研究表明，催乳素是卵巢激素有效刺激母性行为所必需的。在妊娠后半期，胎盘催乳素可能会在这一作用中取代催乳素。尽管催乳素是母性行为的慢性刺激因素，但它也可能在短时间内起作用。催产素能刺激特定品系大鼠的母性行为，但不能刺激其他品系，而且只有在给经雌激素预处理的雌性大鼠脑室内注射时才起作用。有人提出，分娩前后大脑中β-内啡肽水平的下降是母性行为开始的必要条件；吗啡会阻断母性行为的开始，并扰乱哺乳期雌性大鼠正在进行的母性行为和母性攻击行为。然而，在分娩时阻断β-内啡肽的作用也会干扰幼崽清理和胎盘进食。
