Clinical Neuroscience and Neuroimaging, Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
Finetech in Medicine Research Center, School of Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran.
Exp Brain Res. 2024 Jul;242(7):1561-1571. doi: 10.1007/s00221-024-06848-1. Epub 2024 May 16.
In the human brain, the regions responsible for emotion processing, motivation, and memory are heavily influenced by olfaction, whose neural pathway is directly exposed to the outer world. In this study, we used fMRI to examine how different olfactory conditions might affect the functional connectivity circuit underlying working memory in the brain. To this end, 30 adults (aged 20-35), 13 males and 17 females, with high educational levels were chosen. Participants were screened for potential olfactory issues before undergoing the Sniffin' sticks test, which was part of the inclusion criteria. Before imaging, each participant was given the required level of training and was then asked to complete four olfactory tests involving pleasant and unpleasant odors, air, and null stimulation. The results of Seed-based analysis suggested a function connection between the inferior parietal region and the left frontal pole region upon olfactory stimulation with vanilla scent in contrast to null stimulation in this comparison, ROI-based analysis revealed an inverse synchronous among the entorhinal cortex, orbitofrontal cortex, and dorsolateral prefrontal cortex (dlPFC). Both dlPFC and hippocampus were involved in olfactory discrimination between two different stimulants. Our findings indicate the presence of inverse correlations between several regions associated with olfaction and working memory, with pleasant scents leaving a stronger impact on the working memory-related areas, particularly the inferior parietal region.
在人类大脑中，负责情绪处理、动机和记忆的区域受到嗅觉的强烈影响，而嗅觉的神经通路直接暴露于外部世界。在这项研究中，我们使用 fMRI 来研究不同的嗅觉条件如何影响大脑中工作记忆的功能连接回路。为此，我们选择了 30 名（年龄在 20-35 岁之间，男女各 13 名和 17 名）具有高教育水平的成年人。在进行 Sniffin' sticks 测试之前，对参与者进行了潜在嗅觉问题的筛选，该测试是纳入标准的一部分。在成像之前，每个参与者都接受了必要的训练水平，并被要求完成四项涉及愉快和不愉快气味、空气和零刺激的嗅觉测试。种子分析的结果表明，在与零刺激相比，香草气味刺激下，下顶叶区域和左侧额极区域之间存在功能连接，基于 ROI 的分析显示，在眶额皮质、边缘皮质和背外侧前额皮质（dlPFC）之间存在相反的同步。dlPFC 和海马体都参与了两种不同刺激物的嗅觉辨别。我们的研究结果表明，与嗅觉和工作记忆相关的几个区域之间存在负相关，愉快的气味对与工作记忆相关的区域（特别是下顶叶区域）产生更强的影响。
