Department of Psychology, Tulane University, New Orleans, LA 70118, United States.
Physiol Behav. 2012 Feb 28;105(4):1014-20. doi: 10.1016/j.physbeh.2011.11.021. Epub 2011 Nov 29.
When learning to navigate toward a goal in a spatial environment, rodents employ distinct learning strategies that are governed by specific regions of the brain. In the early stages of learning, adult male rats prefer a hippocampus-dependent place strategy over a striatum-dependent response strategy. Alternatively, female rats exhibit a preference for a place strategy only when circulating levels of estradiol are elevated. Notably, male rodents typically perform better than females on a variety of spatial learning tasks, which are mediated by the hippocampus. However, limited research has been done to determine if the previously reported male spatial advantage corresponds with a greater reliance on a place strategy, and, if the male preference for a place strategy is impacted by removal of testicular hormones. A dual-solution water T-maze task, which can be solved by adopting either a place or a response strategy, was employed to determine the effects of biological sex and hormonal status on learning strategy. In the first experiment, male rats made more correct arm choices than female rats during training and exhibited a bias for a place strategy on a probe trial. The results of the second experiment indicated that testicular hormones modulated arm choice accuracy during training, but not the preference for a place strategy. Together, these findings suggest that the previously reported male spatial advantage is associated with a greater reliance on a place strategy, and that only performance during the training phase of a dual-solution learning task is impacted by removal of testicular hormones.
当学习在空间环境中导航到目标时，啮齿动物采用不同的学习策略，这些策略由大脑的特定区域控制。在学习的早期阶段，成年雄性大鼠更喜欢海马体依赖的位置策略，而不是纹状体依赖的反应策略。相比之下，只有当循环中的雌二醇水平升高时，雌性大鼠才会表现出对位置策略的偏好。值得注意的是，雄性啮齿动物通常在各种空间学习任务中的表现优于雌性，而这些任务是由海马体介导的。然而，很少有研究确定以前报道的雄性空间优势是否与对位置策略的更大依赖有关，以及雄性对位置策略的偏好是否受到睾丸激素去除的影响。采用双解决方案水 T 迷宫任务，可以通过采用位置或反应策略来解决，该任务用于确定生物性别和激素状态对学习策略的影响。在第一个实验中，雄性大鼠在训练期间比雌性大鼠做出更多正确的臂选择，并且在探测试验中表现出对位置策略的偏好。第二个实验的结果表明，睾丸激素在训练期间调节臂选择的准确性，但不影响对位置策略的偏好。总之，这些发现表明，以前报道的雄性空间优势与对位置策略的更大依赖有关，只有双解决方案学习任务的训练阶段的表现受到睾丸激素去除的影响。
