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啮齿动物习性系统中的选择反射

Choice reflexes in the rodent habit system
课程网址: http://videolectures.net/rldm2015_gruber_choice_reflexes/  
主讲教师: Aaron Gruber
开课单位: 莱斯布里奇大学
开课时间: 2015-07-28
课程语种: 英语
中文简介:
我们研究了老鼠在奖赏缺失后迅速调整选择的神经机制。动物通常采用一种“失去转换”策略,在这种策略中,它们会在忽略奖励后改变反应。我们惊奇地发现,这种反应在背外侧纹状体(DLS)损伤后大大降低,DLS是一个假设参与习惯逐渐形成的大脑区域。此外,我们发现改进的Q学习模型比对照组和背内侧纹状体(DMS)损伤动物的行为数据更符合,后者是一个与“目标导向”反应相关的区域。基于模型的分析显示,纹状体损伤的动物,特别是DLS,降低了奖赏敏感性和选择机制的随机性。随后的实验表明,通过全身给药安非他明,或在DLS中注入D2型多巴胺受体激动剂(但不输注于DMS)可降低失开关反应。这些数据表明,DLS能够通过低多巴胺(负奖赏预测误差信号)使D2受体失活,从而在奖赏缺失(<15秒)后驱动快速转换。我们提出,这是一种“选择反射”,在错误发生后防止动物重复错误,而其他行为控制系统则更新预期的动作/状态值。
课程简介: We examined the neural mechanisms by which rats rapidly adjust choices following reward omission. Animals often employ a ‘lose-switch’ strategy in which they switch responses following reward omission. We surprisingly found that such responding was greatly reduced following lesions of the dorsolateral striatum (DLS), a brain region hypothesized to be involved in the gradual formation of habits. Moreover, we found that a modified Q-learning model better fit behavioural data from the DLS-lesioned animals than controls or animals with lesions of dorsomedial striatum (DMS), a region associated with ‘goal-directed’ responding. The model-based analysis revealed that animals with striatal lesions, particularly of the DLS, had blunted reward sensitivity and less stochasticity in the choice mechanism. Subsequent experiments showed that lose-switch responding was reduced by systemic administration of amphetamine, or by infusion of agonists for D2 type dopamine receptors in the DLS (but not into DMS). These data reveal that the DLS is able to drive rapid switches following reward omission (< 15 seconds) via inactivation of D2 receptors by periods of low dopamine (negative reward prediction error signal). We propose that this serves as a ‘choice reflex’ following errors that prevents animals from repeating mistakes while other behavioural control systems update expected action/state values.
关 键 词: 背外侧纹状体; 纹状体病变; 选择反射
课程来源: 视频讲座网
数据采集: 2020-12-21:yxd
最后编审: 2020-12-21:yxd
阅读次数: 54