Döcke F, Rohde W, Lange T, Dörner G
Endokrinologie. 1980 Jan;75(1):1-7.
Intact and ovariectomized female rats were bilaterally lesioned in the anterior part of the medial amygdaloid nucleus (AMN) at 15, 21 or 26 days of age. The onset of puberty and the LH concentration in the peripheral serum on the third day after lesioning, respectively, were recorded. Damage to the AMN on day 15 induced a significant delay of vaginal opening and the first puberal ovulation and suppressed completely the castration-induced increase of LH secretion. In contrast, females lesioned on day 21 showed true precocious puberty and a significant elevation of the LH level as compared to the ovariectomized controls. The LH-inhibiting effect of s.c. administered estradiol benzoate (0.05 micrograms/100 g/day) was not diminished by lesions produced at this age. Neither the onset of puberty nor the LH concentration were influenced by lesioning of the AMN on day 26. Estimation of the LH concentration in untreated female rats revealed a distinct decline between 19 and 23 days of age followed by a significant increase between days 24 and 26. The findings indicate a transient LH-inhibiting activity of the medial amygdala in three-week-old female rats that is not related to the negative estrogen feedback. In other species, too, a temporary inhibitory action of the central nervous system may play a significant role in the prepuberal control of gonadotropin secretion.
完整的和卵巢切除的雌性大鼠在15、21或26日龄时双侧损毁内侧杏仁核（AMN）前部。分别记录损毁后第三天的青春期启动情况和外周血清中的促黄体生成素（LH）浓度。15日龄时损毁AMN会导致阴道开口和首次青春期排卵显著延迟，并完全抑制去势诱导的LH分泌增加。相比之下，21日龄时损毁的雌性大鼠表现出真性性早熟，与卵巢切除的对照组相比，LH水平显著升高。皮下注射苯甲酸雌二醇（0.05微克/100克/天）对LH的抑制作用在这个年龄段产生的损毁后并未减弱。26日龄时损毁AMN既不影响青春期启动，也不影响LH浓度。对未处理的雌性大鼠LH浓度的评估显示，在19至23日龄之间有明显下降，随后在24至26日龄之间显著增加。这些发现表明，三周龄雌性大鼠内侧杏仁核存在短暂的LH抑制活性，这与雌激素负反馈无关。在其他物种中，中枢神经系统的暂时抑制作用在青春期前促性腺激素分泌的控制中也可能起重要作用。
