Heikkinen Taneli, Puoliväli Jukka, Liu Li, Rissanen Anna, Tanila Heikki
Department of Neuroscience and Neurology, University of Kuopio, FIN-70211 Kuopio, Finland.
Horm Behav. 2002 Feb;41(1):22-32. doi: 10.1006/hbeh.2001.1738.
This study examined the effects of long-term estrogen treatment (sc 17 beta-estradiol minipellets) on learning in C57BL/6J female and male mice using a position discrimination task in the T-maze and a win-stay task (1/8 arms baited) in the radial arm maze (RAM). In addition, hippocampal monoamines and ChAT activity were measured at the end of the study and correlated to task performance. Female sham-operated (gonadally intact) and ovariectomized (OVX) mice were treated with estrogen either for 7 or 40 days before the behavioral tests and intact male mice for 7 days before the behavioral tests. In sham-operated mice the 40-day estrogen treatment improved RAM performance and in OVX mice both the 7- and 40-day estrogen treatments improved the performance in both maze tasks. The estrogen treatment also improved RAM performance in males. The hippocampal ChAT, NA, 5-HIAA, and DOPAC levels were decreased in OVX mice. Furthermore, the effects of estrogen treatment on the levels of hippocampal 5-HT and its metabolite 5-HIAA were different in sham-operated than in OVX mice. We could find no correlation between cognitive measures and neurochemical variables. This study gives new information about the effects of estrogen on learning and hippocampal neurotransmitters in mice.
本研究使用T迷宫中的位置辨别任务以及放射状臂迷宫（RAM）中的赢则停留任务（八分之一的臂放置诱饵），检测了长期雌激素治疗（皮下植入17β-雌二醇微型丸）对C57BL/6J雌性和雄性小鼠学习能力的影响。此外，在研究结束时测量了海马单胺和胆碱乙酰转移酶（ChAT）活性，并将其与任务表现相关联。雌性假手术（性腺完整）和去卵巢（OVX）小鼠在行为测试前分别接受7天或40天的雌激素治疗，完整雄性小鼠在行为测试前接受7天的雌激素治疗。在假手术小鼠中，40天的雌激素治疗改善了放射状臂迷宫任务的表现；在去卵巢小鼠中，7天和40天的雌激素治疗均改善了两种迷宫任务的表现。雌激素治疗也改善了雄性小鼠在放射状臂迷宫任务中的表现。去卵巢小鼠海马中的ChAT、去甲肾上腺素（NA）、5-羟吲哚乙酸（5-HIAA）和3,4-二羟基苯乙酸（DOPAC）水平降低。此外，假手术小鼠与去卵巢小鼠中，雌激素治疗对海马5-羟色胺（5-HT）及其代谢物5-HIAA水平的影响有所不同。我们未发现认知指标与神经化学变量之间存在相关性。本研究提供了关于雌激素对小鼠学习和海马神经递质影响的新信息。
