Division of Neurosciences, Pablo de Olavide University, 41013-Seville, Spain.
Learn Mem. 2012 Feb 21;19(3):99-106. doi: 10.1101/lm.024760.111.
The neural structures involved in ongoing appetitive and/or observational learning behaviors remain largely unknown. Operant conditioning and observational learning were evoked and recorded in a modified Skinner box provided with an on-line video recording system. Mice improved their acquisition of a simple operant conditioning task by observational learning. Electrical stimulation of the observer's medial prefrontal cortex (mPFC) at a key moment of the demonstration (when the demonstrator presses a lever in order to obtain a reward) cancels out the benefits of observation. In contrast, electrical stimulation of the observer's nucleus accumbens (NAc) enhances observational learning. Ongoing cognitive processes in the demonstrator could also be driven by electrical stimulation of these two structures, preventing the proper execution of the ongoing instrumental task (mPFC) or stopping pellet intake (NAc). Long-term potentiation (LTP) evoked in these two cortical structures did not prevent the acquisition or retrieval process--namely, mPFC and/or NAc stimulation only prevented, or modified, the ongoing behavioral process. The dorsal hippocampus was not involved in either of these two behavioral processes. Thus, both ongoing observational learning and performance of an instrumental task require the active contribution of the mPFC and/or the NAc.
目前仍不清楚参与持续的欲望和/或观察学习行为的神经结构。在一个带有在线视频记录系统的改良斯金纳箱中引发和记录操作性条件反射和观察学习。通过观察学习，小鼠改善了其对简单操作性条件反射任务的获取。在演示的关键时刻（当演示者按下杠杆以获得奖励时）对观察者的内侧前额叶皮层（mPFC）进行电刺激会消除观察的好处。相比之下，电刺激观察者的伏隔核（NAc）增强了观察学习。在这两个结构中进行的持续认知过程也可以通过电刺激来驱动，从而阻止正在进行的工具任务（mPFC）的正确执行或停止颗粒摄入（NAc）。这两个皮质结构中诱发的长时程增强（LTP）并未阻止获取或检索过程——即，mPFC 和/或 NAc 刺激仅阻止或修改了正在进行的行为过程。背侧海马体未参与这两个行为过程中的任何一个。因此，持续的观察学习和工具任务的执行都需要 mPFC 和/或 NAc 的积极贡献。
