Ramírez-Lugo Leticia, Peñas-Rincón Ana, Ángeles-Durán Sandybel, Sotres-Bayon Francisco
Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México, 04510 Ciudad de México, México.
Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México, 04510 Ciudad de México, México
J Neurosci. 2016 Oct 12;36(41):10574-10583. doi: 10.1523/JNEUROSCI.0796-16.2016.
The ability to select an appropriate behavioral response guided by previous emotional experiences is critical for survival. Although much is known about brain mechanisms underlying emotional associations, little is known about how these associations guide behavior when several choices are available. To address this, we performed local pharmacological inactivations of several cortical regions before retrieval of an aversive memory in choice-based versus no-choice-based conditioned taste aversion (CTA) tasks in rats. Interestingly, we found that inactivation of the orbitofrontal cortex (OFC), but not the dorsal or ventral medial prefrontal cortices, blocked retrieval of choice CTA. However, OFC inactivation left retrieval of no-choice CTA intact, suggesting its role in guiding choice, but not in retrieval of CTA memory. Consistently, OFC activity increased in the choice condition compared with no-choice, as measured with c-Fos immunolabeling. Notably, OFC inactivation did not affect choice behavior when it was guided by innate taste aversion. Consistent with an anterior insular cortex (AIC) involvement in storing taste memories, we found that AIC inactivation impaired retrieval of both choice and no-choice CTA. Therefore, this study provides evidence for OFC's role in guiding choice behavior and shows that this is dissociable from AIC-dependent taste aversion memory. Together, our results suggest that OFC is required and recruited to guide choice selection between options of taste associations relayed from AIC.
Survival and mental health depend on being able to choose stimuli not associated with danger. This is particularly important when danger is associated with stimuli that we ingest. Although much is known about the brain mechanisms that underlie associations with dangerous taste stimuli, very little is known about how these stored emotional associations guide behavior when it involves choice. By combining pharmacological and immunohistochemistry tools with taste-guided tasks, our study provides evidence for the key role of orbitofrontal cortex activity in choice behavior and shows that this is dissociable from the adjacent insular cortex-dependent taste aversion memory. Understanding the brain mechanisms that underlie the impact that emotional associations have on survival choice behaviors may lead to better treatments for mental disorders characterized by emotional decision-making deficits.
在先前情绪体验的引导下选择适当行为反应的能力对生存至关重要。尽管我们对情绪联想背后的脑机制了解很多，但对于当有多种选择时这些联想如何引导行为却知之甚少。为了解决这个问题，我们在大鼠基于选择与非基于选择的条件性味觉厌恶（CTA）任务中，在厌恶记忆提取前对几个皮质区域进行了局部药理学失活处理。有趣的是，我们发现眶额皮质（OFC）失活会阻断基于选择的CTA的提取，但背侧或腹内侧前额叶皮质失活则不会。然而，OFC失活并不影响非基于选择的CTA的提取，这表明其在引导选择方面发挥作用，但在CTA记忆提取中不起作用。一致地，通过c-Fos免疫标记测量，与非选择条件相比，在选择条件下OFC的活性增加。值得注意的是，当由先天味觉厌恶引导时，OFC失活并不影响选择行为。与前岛叶皮质（AIC）参与储存味觉记忆一致，我们发现AIC失活会损害基于选择和非基于选择的CTA的提取。因此，本研究为OFC在引导选择行为中的作用提供了证据，并表明这与依赖AIC的味觉厌恶记忆是可分离的。总之，我们的结果表明，OFC是引导从AIC传递的味觉联想选项之间的选择所必需且会被招募的。
生存和心理健康取决于能够选择与危险无关的刺激。当危险与我们摄入的刺激相关时，这一点尤为重要。尽管我们对与危险味觉刺激相关联的脑机制了解很多，但对于这些储存的情绪联想在涉及选择时如何引导行为却知之甚少。通过将药理学和免疫组织化学工具与味觉引导任务相结合，我们的研究为眶额皮质活动在选择行为中的关键作用提供了证据，并表明这与相邻的依赖岛叶皮质的味觉厌恶记忆是可分离的。了解情绪联想对生存选择行为产生影响背后的脑机制，可能会为以情绪决策缺陷为特征的精神障碍带来更好的治疗方法。
