This study investigated the role of calcium²⁺/calmodulin-dependent protein kinase II (CaMKII), a protein in the second messenger pathway of NMDA receptors, in the ventral tegmental area (VTA) in the acquisition and performance of conditioned approach learning. Male Long-Evans rats (N = 79) were exposed to 3 (to test acquisition) or 7 (to test performance) conditioning sessions in which they received 30 paired presentations of a light stimulus (CS) and a food pellet (US) on a random time schedule. These conditioning sessions were then followed by one 30-min session without the CS or US and lastly by a CS-only test session, where only the light stimulus was presented (without food) according to the same schedule as the conditioning sessions. Bilateral intra-VTA injections of KN93 (vehicle, 3.0, 4.5 or 6.0 μg/0.5 μL), a CaMKII inhibitor, were administered prior to each conditioning session to test effects on the acquisition of conditioned approach or prior to the CS-only test session to test effects on the performance of conditioned approach. KN93, when given prior to conditioning sessions, significantly reduced the number of conditioned approach responses emitted during CS presentations in the CS-only test. When KN93 was given prior to the CS-only test it had no effect. These results suggest that CaMKII activation in the VTA is necessary for the acquisition, but not the performance, of reward-related learning.

本研究调查了腹侧被盖区 (VTA) 的钙²⁺ /钙调蛋白依赖性蛋白激酶 II (CaMKII)（一种 NMDA 受体第二信使通路中的蛋白质）在条件性接近学习的习得和表现中的作用。雄性 Long-Evans 大鼠 (N = 79) 接受 3 次（测试采集）或 7 次（测试表现）条件反射训练，其中它们接受 30 组光刺激 (CS) 和食物颗粒 (US) 的配对呈现。随机的时间表。这些调节课程之后是 30 分钟的无 CS 或 US 的课程，最后是仅 CS 测试课程，其中根据与调节课程相同的时间表仅提供光刺激（无食物）。在每次条件训练之前或在仅 CS 测试之前，进行双侧 VTA 内注射 KN93（媒介物，3.0、4.5 或 6.0 μg/0.5 μL）（一种 CaMKII 抑制剂），以测试对获得条件方法的效果测试条件方法对性能的影响。 KN93，当在条件训练之前给予时，显着减少了在仅 CS 测试中的 CS 演示期间发出的条件接近反应的数量。当在仅 CS 测试之前给予 KN93 时，没有效果。这些结果表明，VTA 中的 CaMKII 激活对于奖励相关学习的获得（而非表现）是必要的。