Angulo Rocio, Bustamante Javier, Estades Vania, Ramírez Valeska, Jorquera Belén
Instituto de Ciencias Sociales, Universidad de O'Higgins, Rancagua, Chile.
Front Behav Neurosci. 2020 Jun 22;14:107. doi: 10.3389/fnbeh.2020.00107. eCollection 2020.
This study aimed to test whether male and female rats might show differences in cue competition effects in a conditioned taste aversion (CTA) model. Experiment 1 tested for sex differences in overshadowing. After conditioning of a flavored compound AB or only one simple flavor A (being A and B a solution of sugar 10% and salt 1%, counterbalanced), consumption of the A solution at test was larger in the former than in the latter case only in males. Thus, the usual effect of overshadowing was observed in males but not in females. Experiment 2 examined sex differences in blocking with the same stimuli used in Experiment 1. After conditioning of AB, the consumption of B was larger for the animals that previously received a single conditioning trial with A than for those that received unpaired presentations of A and the illness. As observed in Experiment 1, the typical blocking effect appeared only in males but not in females. The present findings thus support the hypothesis that sex dimorphism might be expressed in classical conditioning, or at least, in cue competition effects such as overshadowing and blocking with a taste aversion model.
本研究旨在测试雄性和雌性大鼠在条件性味觉厌恶（CTA）模型中是否可能表现出线索竞争效应的差异。实验1测试了遮蔽效应中的性别差异。在用调味化合物AB或仅一种简单味道A进行条件反射后（A和B分别为10%的糖溶液和1%的盐溶液，两者平衡），仅在雄性大鼠中，测试时A溶液的消耗量在前一种情况下比后一种情况更大。因此，在雄性大鼠中观察到了通常的遮蔽效应，而在雌性大鼠中未观察到。实验2使用与实验1相同的刺激物检查了阻塞效应中的性别差异。在用AB进行条件反射后，与那些接受A与疾病非配对呈现的动物相比，先前接受过一次A单一条件反射试验的动物对B的消耗量更大。如在实验1中所观察到的，典型的阻塞效应仅出现在雄性大鼠中，而在雌性大鼠中未出现。因此，本研究结果支持这样一种假设，即性别二态性可能在经典条件反射中表现出来，或者至少在诸如遮蔽效应和味觉厌恶模型中的阻塞效应等线索竞争效应中表现出来。
