Kanit L, Koylu E O, Erdogan O, Pogun S
Ege University, Center for Brain Research, Bornova, Izmir, Turkey.
Brain Res Bull. 2005 Aug 15;66(3):189-202. doi: 10.1016/j.brainresbull.2005.04.012.
The aim of the present study was to investigate sex differences in learning strategies and to elucidate the mechanisms, which may underlie these differences. In two separate experiments, rats were presented with different strategies that could be employed to learn the position of a platform in a water maze (WM); furthermore, rats received treatments that could influence these strategies. In the first experiment, we demonstrated that the response-learning paradigm can be applied to the WM and can be compared with visually cued learning and reversal learning. Naïve rats of either sex could acquire this protocol relatively easily. On the probe trial, where the rats are presented with a choice between using response versus visually cued learning, initially response learning was preferred, however, during these experiments, laterality emerged as a significant factor and rats trained to turn right had difficulty in reversing the learned pattern to find the platform. The second part of our study evaluated the effects of nicotine and nitric oxide synthase (NOS) inhibition on the aforementioned parameters. Drug treatments impaired acquisition compared to saline treatments and the effect was more pronounced with NOS inhibition. During the probe trial, while NOS inhibition enhanced the right-side bias in both sexes, nicotine treatment had the same effect only in males. In conclusion, naïve rats can acquire place learning using visible cues or response learning; however, there is a right side bias in both sexes and the laterality effect is more pronounced in male rats. In drug-treated animals, while NOS inhibition enhances laterality (right bias) in both sexes similarly, nicotine modifies the cognitive strategy in a sexually dimorphic manner by augmenting the right bias only in male rats.
本研究的目的是调查学习策略中的性别差异，并阐明这些差异可能潜在的机制。在两个独立的实验中，给大鼠呈现不同的策略，使其用于学习水迷宫（WM）中平台的位置；此外，大鼠接受了能够影响这些策略的处理。在第一个实验中，我们证明了反应学习范式可应用于水迷宫，并且可以与视觉线索学习和逆向学习进行比较。任何性别的未受过训练的大鼠都能相对容易地习得该实验方案。在探测试验中，当让大鼠在使用反应学习与视觉线索学习之间进行选择时，最初反应学习更受青睐，然而，在这些实验过程中，偏侧性成为一个重要因素，训练为向右转的大鼠很难改变已习得的模式来找到平台。我们研究的第二部分评估了尼古丁和一氧化氮合酶（NOS）抑制对上述参数的影响。与生理盐水处理相比，药物处理损害了学习过程，并且一氧化氮合酶抑制的影响更明显。在探测试验期间，虽然一氧化氮合酶抑制增强了两性的右侧偏好，但尼古丁处理仅在雄性大鼠中产生相同的效果。总之，未受过训练的大鼠可以使用可见线索或反应学习来习得位置学习；然而，两性都存在右侧偏好且在雄性大鼠中偏侧性效应更明显。在药物处理的动物中，虽然一氧化氮合酶抑制同样增强了两性的偏侧性（右侧偏好），但尼古丁以性别差异的方式改变认知策略，仅增强雄性大鼠的右侧偏好。
