Cameron N M, Ha G K, Erskine M S
Department of Biology, Boston University, Boston, MA 02215, USA.
J Neuroendocrinol. 2004 Sep;16(9):750-7. doi: 10.1111/j.1365-2826.2004.01231.x.
In the female rat, the integrity of the ventral noradrenergic bundle (VNAB) is necessary to carry stimuli from the uterine cervix and vagina to brain areas involved in mating-induced pseudopregnancy. Because adrenal hormones are known to alter noradrenergic function, we examined whether adrenalectomy altered mating-induced Fos expression in the A1 and A2 noradrenergic cell groups that project through the VNAB. Ovariectomized females were adrenalectomized (ADX) or sham-operated (Sham) and, 2 weeks after surgery, were given oestrogen and progesterone and mated. They received 15 intromissions, five intromissions or 15 mounts-without-intromission (mounts-only) from a male. Two hours after mating, rats were perfused and brains were collected; controls were perfused after being taken directly from their home cage. After immunocytochemical staining, Fos-immunoreactive (Fos-IR) and dopamine-beta-hydroxylase-immunoreactive (DBH-IR) cells and the percentage of DBH cells that were labelled with Fos (% DBH/Fos) were counted. In the A1 area, Fos-IR and percentage DBH/Fos were not affected by adrenalectomy. Although an overall effect of mating treatment was found for both measures, no specific mating treatment increased labelled cells above home cage levels. In the caudal, middle and rostral A2, 15 intromissions induced a significant increase in Fos-IR in Sham females above all other groups and a higher percentage of DBH/Fos in the middle and rostral A2 areas. ADX females showed no rise in either Fos-IR or percentage DBH/Fos after 15 intromissions. However, in the middle and rostral A2, ADX females showed significantly increased Fos-IR and percentage DBH/Fos after mounts-only treatment above Sham mounts-only females and all other ADX groups. These results demonstrate that adrenal hormones suppress activation of A2 cells to mounts-only stimuli but contribute to A2 activation in response to intromissions from males. The latter effect may result from stress associated with receipt of vaginocervical stimulation during mating.
在雌性大鼠中，腹侧去甲肾上腺素能束（VNAB）的完整性对于将来自子宫颈和阴道的刺激传递到参与交配诱导的假孕的脑区是必要的。由于已知肾上腺激素会改变去甲肾上腺素能功能，我们研究了肾上腺切除术是否会改变通过VNAB投射的A1和A2去甲肾上腺素能细胞群中交配诱导的Fos表达。将卵巢切除的雌性大鼠进行肾上腺切除术（ADX）或假手术（Sham），术后2周，给予雌激素和孕酮并进行交配。它们接受来自雄性的15次插入、5次插入或15次无插入的爬跨（仅爬跨）。交配后2小时，对大鼠进行灌注并收集大脑；对照组直接从其饲养笼中取出后进行灌注。免疫细胞化学染色后，计数Fos免疫反应性（Fos-IR）和多巴胺-β-羟化酶免疫反应性（DBH-IR）细胞以及被Fos标记的DBH细胞百分比（%DBH/Fos）。在A1区域，肾上腺切除术不影响Fos-IR和%DBH/Fos。尽管对于这两种测量方法都发现了交配处理的总体效应，但没有特定的交配处理使标记细胞增加到高于饲养笼水平。在尾侧、中间和头侧A2区域，15次插入诱导假手术雌性大鼠的Fos-IR显著高于所有其他组，并且在中间和头侧A2区域的DBH/Fos百分比更高。15次插入后，肾上腺切除的雌性大鼠的Fos-IR或DBH/Fos百分比均未升高。然而，在中间和头侧A2区域，仅爬跨处理后，肾上腺切除的雌性大鼠的Fos-IR和DBH/Fos百分比显著高于假手术仅爬跨的雌性大鼠和所有其他肾上腺切除组。这些结果表明，肾上腺激素抑制A2细胞对仅爬跨刺激的激活，但有助于A2细胞对来自雄性的插入的反应性激活。后一种效应可能是由于交配期间接受阴道宫颈刺激相关的应激所致。
