Terkel J, Witcher J A, Adler N T
Department of Zoology, Tel Aviv University, Ramat Aviv, Israel.
Horm Behav. 1990 Mar;24(1):40-9. doi: 10.1016/0018-506x(90)90025-s.
Successful pregnancy in the female rat depends upon two sets of physiological events: (1) transport of gametes (sperm and egg) through the reproductive tract so that fertilization can be effected and (2) establishment of an appropriate hormonal environment (progestational state) so that the fertilized egg can implant in the uterus and be maintained during subsequent gestation. This study highlights the independence of the mechanisms controlling the gametic and hormonal aspects of pregnancy by temporally separating the introduction of sperm into the female from the stimulation that triggers the progestational hormonal response. The progestational state was initiated by electrical stimulation of the cervix, and sperm was introduced directly into the uterus by artificial insemination. Although these two events were separated by up to 3 days, pregnancy could ensue. Cervical stimulation, normally a consequence of male intromission behavior, establishes a condition in the central nervous system, a "memory" that signals the probable induction of pregnancy. Without this "memory," animals with a short estrous cycle would continue to cycle after mating, thereby producing a hormonal environment incompatible with implantation. The "memory" is manifested by daily surges of prolactin irrespective of fertilization. This is the first physiological demonstration that a "memory" of cervical stimulation can be called upon to support a viable pregnancy.
（1）配子（精子和卵子）通过生殖道运输，以便实现受精；（2）建立适当的激素环境（孕激素状态），使受精卵能够植入子宫并在随后的妊娠期得以维持。本研究通过在时间上分离将精子引入雌性体内与触发孕激素反应的刺激，突出了控制妊娠配子和激素方面机制的独立性。通过对子宫颈进行电刺激引发孕激素状态，并通过人工授精将精子直接引入子宫。尽管这两个事件相隔长达3天，但仍可受孕。子宫颈刺激通常是雄性插入行为的结果，它在中枢神经系统中建立一种状态，一种“记忆”，该“记忆”表明可能会诱发妊娠。没有这种“记忆”，发情周期短的动物在交配后会继续循环，从而产生与着床不相容的激素环境。这种“记忆”表现为无论是否受精，催乳素都会每日激增。这是首次从生理学上证明子宫颈刺激的“记忆”可用于支持可行的妊娠。
