Panayi Marios C, Killcross Simon
School of Psychology, UNSW Sydney, Sydney, NSW 2052, Australia.
National Institute on Drug Abuse Intramural Research Program, Cellular Neurobiology Research Branch, Behavioral Neurophysiology Research Section, 251 Bayview Blvd., Baltimore, MD 21224, USA.
Cereb Cortex Commun. 2021 Feb 9;2(1):tgab010. doi: 10.1093/texcom/tgab010. eCollection 2021.
The orbitofrontal cortex (OFC) is a critical structure in the flexible control of value-based behaviors. OFC dysfunction is typically only detected when task or environmental contingencies change, against a backdrop of apparently intact initial acquisition and behavior. While intact acquisition following OFC lesions in simple Pavlovian cue-outcome conditioning is often predicted by models of OFC function, this predicted null effect has not been thoroughly investigated. Here, we test the effects of lesions and temporary muscimol inactivation of the rodent lateral OFC on the acquisition of a simple single cue-outcome relationship. Surprisingly, pretraining lesions significantly enhanced acquisition after overtraining, whereas post-training lesions and inactivation significantly impaired acquisition. This impaired acquisition to the cue reflects a disruption of behavioral control and not learning since the cue could also act as an effective blocking stimulus in an associative blocking procedure. These findings suggest that even simple cue-outcome representations acquired in the absence of OFC function are impoverished. Therefore, while OFC function is often associated with flexible behavioral control in complex environments, it is also involved in very simple Pavlovian acquisition where complex cue-outcome relationships are irrelevant to task performance.
眶额皮质（OFC）是基于价值的行为灵活控制中的关键结构。OFC功能障碍通常仅在任务或环境意外情况发生变化时才被检测到，且初始习得和行为表面上完好无损。虽然在简单的巴甫洛夫线索-结果条件反射中，OFC损伤后的习得完好通常由OFC功能模型预测，但这种预测的无效效应尚未得到充分研究。在这里，我们测试了啮齿动物外侧OFC的损伤和临时应用蝇蕈醇失活对简单单一线索-结果关系习得的影响。令人惊讶的是，预训练损伤在过度训练后显著增强了习得，而后训练损伤和失活则显著损害了习得。对线索的这种习得受损反映了行为控制的破坏，而非学习，因为该线索在联想性阻断程序中也可作为有效的阻断刺激。这些发现表明，即使在没有OFC功能的情况下获得的简单线索-结果表征也不完整。因此，虽然OFC功能通常与复杂环境中的灵活行为控制相关，但它也参与非常简单的巴甫洛夫式习得，其中复杂的线索-结果关系与任务表现无关。
