Clancy A N, Zumpe D, Michael R P
Department of Biology, Georgia State University, Kell Hall, 24 Peachtree Center Avenue, Atlanta, Georgia, 30302-4010, USA.
Horm Behav. 2000 Sep;38(2):86-93. doi: 10.1006/hbeh.2000.1602.
Mating was studied in sexually experienced, gonadally intact male rats assigned to two surgical groups matched on the basis of mean mounting frequency during behavioral screening trials conducted prior to the study. Estradiol (E(2)) was delivered bilaterally into the medial preoptic area (MPO) of experimental males by means of hormone-coated implants, and fadrozole was given sc (0.25 mg/kg/day) via osmotic minipumps to block E(2) formation from testicular testosterone throughout the brain. Control males received blank bilateral implants in the MPO and sc fadrozole. After the completion of behavioral testing, immunocytochemical comparisons of the brains from experimental and control rats were made using the H222 antiestrogen receptor (ER) antibody, whose labeling is inhibited by the presence of E(2). The histology demonstrated that E(2) was confined exclusively to the MPO of experimental males but was absent throughout the brains of controls. In controls, mounting decreased significantly by the 7th day after surgery compared with presurgical levels and did not recover. In contrast, on all postsurgical days, the mounting frequency of the experimental group was significantly higher than that of controls. Although experimental males also showed an initial, significant postsurgical decline in mounting frequency, it recovered completely by the 28th postoperative day. Ejaculations declined significantly after surgery in both groups but, unlike in controls whose performance remained low, ejaculations in experimental males partially recovered and were significantly higher than in controls during the postoperative period. Results showed that ER-containing neurons in the MPO influence male rat copulatory behavior.
在性经验丰富、性腺完整的雄性大鼠中研究了交配行为。这些大鼠被分为两个手术组，在研究前进行的行为筛选试验中，根据平均骑跨频率进行匹配。通过激素包被的植入物将雌二醇（E₂）双侧注入实验雄性大鼠的内侧视前区（MPO），并通过渗透微型泵皮下注射法倔唑（0.25 mg/kg/天），以阻断睾丸睾酮在整个大脑中形成E₂。对照雄性大鼠在MPO接受双侧空白植入物并皮下注射法倔唑。行为测试完成后，使用H222抗雌激素受体（ER）抗体对实验大鼠和对照大鼠的大脑进行免疫细胞化学比较，该抗体的标记会受到E₂的抑制。组织学表明，E₂仅局限于实验雄性大鼠的MPO，但在对照大鼠的整个大脑中均不存在。在对照组中，与术前水平相比，术后第7天骑跨行为显著减少且未恢复。相比之下，在所有术后天数，实验组的骑跨频率均显著高于对照组。尽管实验雄性大鼠术后骑跨频率也出现了最初的显著下降，但在术后第28天完全恢复。两组术后射精次数均显著下降，但与表现持续较低的对照组不同，实验雄性大鼠的射精次数部分恢复，且在术后期间显著高于对照组。结果表明，MPO中含ER的神经元会影响雄性大鼠的交配行为。
