Daniel J M, Roberts S L, Dohanich G P
Department of Psychology, Tulane University, New Orleans, LA 70118, USA.
Physiol Behav. 1999 Mar;66(1):11-20. doi: 10.1016/s0031-9384(98)00272-8.
The effects of gonadal hormones and environment on performance in an eight-arm radial maze and in the Morris water maze were determined in female rats. Long-Evans female rats were ovariectomized or sham ovariectomized at 35 days of age, and housed in complex environments or in isolation for the duration of the study. One month following surgeries, spatial working memory performance in the radial maze was assessed. Exposure to complex environmental conditions independently enhanced performance, as indicated by increased arm choice accuracy during 20 days of maze training. Additionally, gonadally intact females significantly outperformed ovariectomized females before cyclicity was disrupted by food deprivation. Following radial maze training, spatial reference memory performance was assessed in the same females utilizing the Morris water maze. Gonadally intact females housed in isolation performed significantly more poorly during 16 days of place training trials and displayed significantly shorter times in the platform quadrants and fewer target crossings during probe trials than gonadally intact and ovariectomized females housed in complex environments and ovariectomized rats housed in isolation. Consequently, acquisition and retention of the water maze was impaired by the presence of ovaries, and this impairment was counteracted by exposure to complex environments. Performance did not differ between groups on cued trials, indicating that sensorimotor and motivational functions did not differ between groups. Results of these experiments indicate that endogenous gonadal hormones can differentially affect performance on tasks of spatial working and spatial reference memory, and that environmental conditions can interact with gonadal hormones to affect behavior.
在雌性大鼠中确定了性腺激素和环境对八臂放射状迷宫及莫里斯水迷宫中行为表现的影响。将长-伊文斯雌性大鼠在35日龄时进行卵巢切除或假手术卵巢切除，并在研究期间饲养于复杂环境或单独饲养。手术后一个月，评估放射状迷宫中的空间工作记忆表现。如迷宫训练20天期间手臂选择准确性增加所示，暴露于复杂环境条件可独立提高行为表现。此外，在食物剥夺扰乱周期性之前，性腺完整的雌性大鼠表现明显优于卵巢切除的雌性大鼠。在放射状迷宫训练后，利用莫里斯水迷宫评估相同雌性大鼠的空间参考记忆表现。与饲养于复杂环境中的性腺完整和卵巢切除的雌性大鼠以及单独饲养的卵巢切除大鼠相比，单独饲养的性腺完整雌性大鼠在16天的位置训练试验中表现明显更差，在探测试验中在平台象限的时间明显更短，目标穿越次数更少。因此，卵巢的存在损害了水迷宫的习得和记忆保持，而这种损害可通过暴露于复杂环境来抵消。在提示试验中各实验组表现无差异，表明各实验组的感觉运动和动机功能无差异。这些实验结果表明，内源性性腺激素可不同程度地影响空间工作和空间参考记忆任务的表现，并且环境条件可与性腺激素相互作用以影响行为。
