Department of Child and Adolescent Psychiatry, New York University School of Medicine, New York, USA.
Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, USA.
Sci Rep. 2017 Nov 6;7(1):14602. doi: 10.1038/s41598-017-15109-x.
Cerebral lateralization is expressed at both the structural and functional levels, and can exist as either a stable characteristic or as a dynamic feature during behavior and development. The anatomically relatively simple olfactory system demonstrates lateralization in both human and non-human animals. Here, we explored functional lateralization in both primary olfactory cortex - a region critical for odor memory and perception- and orbitofrontal cortex (OFC) - a region involved in reversal learning- in rats performing an odor learning and reversal task. We find significant asymmetry in both olfactory and orbitofrontal cortical odor-evoked activity, which is expressed in a performance- and task-dependent manner. The emergence of learning-dependent asymmetry during reversal learning was associated with decreased functional connectivity both between the bilateral OFC and between the OFC-olfactory cortex. The results suggest an inter-hemispheric asymmetry and olfactory cortical functional separation that may allow multiple, specialized processing circuits to emerge during a reversal task requiring behavioral flexibility.
大脑的偏侧性在结构和功能水平上都有表现，可以是行为和发育过程中的稳定特征，也可以是动态特征。在人类和非人类动物中，解剖结构相对简单的嗅觉系统也表现出偏侧性。在这里，我们在大鼠执行气味学习和反转任务时，探索了初级嗅觉皮层（对气味记忆和感知至关重要的区域）和眶额皮层（OFC，参与反转学习的区域）的功能偏侧性。我们发现，嗅觉和眶额皮质的气味诱发活动都存在显著的不对称性，这种不对称性以性能和任务依赖的方式表现出来。在反转学习过程中，学习依赖性不对称的出现与双侧 OFC 之间以及 OFC-嗅觉皮层之间的功能连接减少有关。结果表明，在需要行为灵活性的反转任务中，可能会出现半球间的不对称和嗅觉皮层的功能分离，从而允许出现多个专门的处理回路。
