Photoperiodic and pineal influences on estrogen-stimulated behaviors in female Syrian hamsters.
Photoperiodic and pineal influences on estrogen-stimulated behaviors in female Syrian hamsters.
复制标题
光周期和松果体对雌性叙利亚仓鼠雌激素刺激行为的影响。
DOI：
10.1016/0031-9384(93)90038-h
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发表时间：
1993
影响因子：
2.9
通讯作者：
Powers,JB
中科院分区：
文献类型：
--
作者：
Karp,JD;Powers,JB
三项实验研究了短光周期暴露对雌激素促进运动活动和脊柱前凸的影响。在实验1中，给切除卵巢的雌性仓鼠注射外源雌激素以刺激跑轮的运动活动。雌激素在长光周期组中有效，但在短光周期组中不刺激跑轮活动。在实验2中，检查了松果体在介导光周期对雌性仓鼠行为的影响中的作用。在短光周期雌性中，雌激素诱导的运动活动和雌激素+孕激素刺激的脊柱前凸行为均显着降低。在松果体切除的仓鼠中，这两种光周期效应都不存在。假松果体切除、短光周期雌性表现出行为缺陷；松果体切除的仓鼠在短光周期则没有。实验3仅研究脊柱前凸并使用激素注射而不是硅橡胶植入物来施用雌激素。实验2中观察到的光周期和松果体效应在实验3中得到了重复。此外，短光周期暴露对脊柱前凸反应性的抑制是雌激素剂量依赖性的。当使用 2 μg 环戊丙酸雌二醇时存在光周期效应，但当使用较高雌激素剂量时则不存在光周期效应。这些发现是在其他结果的背景下讨论的，其他结果表明光周期对仓鼠脊柱前凸的影响是独立于松果体的。
Three experiments investigated the effects of short photoperiod exposure on the estrogenic facilitation of locomotor activity and lordosis. In Experiment 1, ovariectomized female hamsters were administered exogenous estrogen to stimulate locomotor activity in running wheels. Estrogen was effective in the long photoperiod group but did not stimulate running-wheel activity in the short photoperiod group. In Experiment 2, the role of the pineal gland in mediating photoperiodic influences on female hamster behavior was examined. Both estrogen-induced locomotor activity and estrogen + progesterone-stimulated lordosis behavior were significantly reduced in short photoperiod females. Both these photoperiodic effects were absent in pinealectomized hamsters. Sham-pinealectomized, short photoperiod females expressed behavioral deficits; pinealectomized hamsters in the short photoperiod did not. Experiment 3 investigated lordosis only and used hormone injections rather than silastic implants to administer estrogen. The photoperiodic and pineal effects observed in Experiment 2 were replicated in Experiment 3. Additionally, the suppression of lordosis responsiveness by short photoperiod exposure was estrogen dose dependent. Photoperiodic effects were present when 2 μg estradiol cypionate was used but absent when higher estrogen doses were used. These findings are discussed in the context of other results that suggested photoperiodic effects on hamster lordosis were pineal independent.