Carballo-Márquez Anna, Vale-Martínez Anna, Guillazo-Blanch Gemma, Torras-Garcia Meritxell, Boix-Trelis Núria, Martí-Nicolovius Margarita
Departament de Psicobiologia i Metodologia de les Ciències de la Salut, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain.
Learn Mem. 2007 Sep 6;14(9):616-24. doi: 10.1101/lm.597507. Print 2007 Sep.
The present experiments determined the consequences of blocking muscarinic cholinergic receptors of the prelimbic (PL) cortex in the acquisition and retention of an odor-reward associative task. Rats underwent a training test (five trials) and a 24-h retention test (two retention trials and two relearning trials). In the first experiment, rats were bilaterally infused with scopolamine (20 or 5 microg/site) prior to training. Although scopolamine rats showed acquisition equivalent to PBS-injected controls, they exhibited weakened performance in the 24-h retention test measured by number of errors. In the second experiment, rats were injected with scopolamine (20 microg/site) immediately or 1 h after training and tested 24 h later. Scopolamine rats injected immediately showed severe amnesia detected in two performance measures (errors and latencies), demonstrating deficits in retention and relearning, whereas those injected 1 h later showed good 24-h test performance, similar to controls. These results suggest that muscarinic transmission in the PL cortex is essential for early memory formation, but not for acquisition, of a rapidly learned odor discrimination task. Findings corroborate the role of acetylcholine in consolidation processes and the participation of muscarinic receptors in olfactory associative tasks.
本实验确定了在前边缘（PL）皮质阻断毒蕈碱胆碱能受体对气味-奖励联想任务的习得和保持的影响。大鼠接受了一次训练测试（五次试验）和一次24小时的保持测试（两次保持试验和两次再学习试验）。在第一个实验中，大鼠在训练前双侧注射东莨菪碱（20或5微克/部位）。尽管注射东莨菪碱的大鼠表现出与注射PBS的对照组相当的习得能力，但在通过错误数量衡量的24小时保持测试中，它们的表现有所减弱。在第二个实验中，大鼠在训练后立即或1小时后注射东莨菪碱（20微克/部位），并在24小时后进行测试。立即注射东莨菪碱的大鼠在两项表现指标（错误和潜伏期）中表现出严重的失忆，表明在保持和再学习方面存在缺陷，而1小时后注射东莨菪碱的大鼠在24小时测试中表现良好，与对照组相似。这些结果表明PL皮质中的毒蕈碱传递对于快速习得的气味辨别任务的早期记忆形成至关重要，但对于习得并非如此。研究结果证实了乙酰胆碱在巩固过程中的作用以及毒蕈碱受体在嗅觉联想任务中的参与。
