Characterizing the primary olfactory subregions of the human amygdala

人类杏仁核的几个亚区接受来自嗅球的直接投射，但功能性的 并且这些嗅觉投射的解剖学特性还没有被很好地理解。啮齿动物研究已经开始 揭示了这些嗅觉杏仁核亚区在介导嗅觉引导的社会性行为中的功能， 和接近/避免行为。然而，来自嗅觉的投射存在显著差异， 种间的鳞茎到杏仁核。例如，在啮齿动物中，内侧杏仁核接收高密度的 副嗅球的纤维与此形成鲜明对比的是，人类完全没有辅助嗅觉系统。 在主要嗅球投射的特定杏仁核靶点上也存在其他明显差异 物种之间，虽然这些目标尚未在人类中得到很好的表征，进一步强调了 需要在这方面进行人类研究。本提案的目标是描述解剖学特征， 嗅觉投射到人类杏仁核的功能特性。我们将采取多方面的 方法，结合功能性神经成像，电生理学和刺激，这将加强 重复性和严谨性。目标1的目标是在解剖学和功能上定位 人类杏仁核的初级嗅觉皮层区域。在结构层面上，我们将使用一种新颖的多- 拍摄扩散加权成像序列定位到杏仁核亚区的嗅觉投射。在 功能水平，我们将使用静息fMRI结合k均值聚类算法包裹杏仁核 基于不同的全脑功能连接概况的子区域，以及与事件相关的功能性fMRI 定位杏仁核的气味反应分区。目标2的目标是阐明不同的 杏仁核亚区在嗅觉感知中的作用我们将使用事件相关功能磁共振成像来获得高分辨率的 多变量信号从杏仁核在嗅觉知觉任务。目标3的目标是评估 杏仁核亚区在嗅觉感知中的必要性。我们将使用颅内脑电图技术， 测量不同的嗅觉知觉决定，在临床交付，临床规定，破坏性 直接对人体杏仁核进行电刺激拟议的研究将提供详细的 杏仁核亚区的功能和解剖学特性的表征， 包括杏仁核内侧核、杏仁核皮质和杏仁核周围皮质。最近 研究表明，这些杏仁核前部和中部区域可能在突发意外死亡中发挥作用， 癫痫（SUDEP），这是颞叶癫痫患者死亡的主要原因， 已知原因或治疗。进一步了解这些功能和结构特性， 大脑区域对这些患者具有很强的临床重要性。

Several subregions of the human amygdala receive direct projections from the olfactory bulb, yet the functional and anatomical properties of these olfactory projections are not well understood. Rodent studies have begun to shed light on the functions of some of these olfactory amygdala subregions in mediating olfactory-guided social and approach/avoid behaviors. However, there are significant differences in the projections from the olfactory bulb to the amygdala between species. For example, in rodents, the medial amygdala receives highly dense fibers from the accessory olfactory bulb. In stark contrast, humans lack an accessory olfactory system entirely. There are also other apparent differences in the specific amygdalar targets of main olfactory bulb projections between species, although these targets have not been well-characterized in humans, further highlighting the need for human studies in this area. The goal of this proposal is to characterize the anatomical and functional properties of the olfactory projections into the human amygdala. We will take a multifaceted approach, combining functional neuroimaging, electrophysiology and stimulation, which will strengthen the reproducibility and rigor of our findings. The goal of Aim 1 is to anatomically and functionally localize the primary olfactory cortical regions of the human amygdala. At the structural level, we will use a novel new multi- shot diffusion-weighted imaging sequence to localize olfactory projections into amygdala subregions. At the functional level, we will use resting fMRI combined with k-means clustering algorithms to parcellate amygdalar subregions based on distinct whole-brain functional connectivity profiles, and event-related fMRI to functionally localize odor-responsive subregions of the amygdala. The goal of Aim 2 is to shed light on the roles of distinct amygdala subregions in olfactory perception. We will use event-related fMRI to acquire high-resolution multivariate signals from the amygdala during olfactory perceptual tasks. The goal of Aim 3 is to assess the necessity of the amygdala subregions in olfactory perception. We will use intracranial EEG techniques to measure different olfactory perceptual decisions during clinician-delivered, clinically prescribed, disruptive electrical stimulation directly into the human amygdala. The proposed studies will provide a detailed characterization of the functional and anatomical properties of an under-studied group of amygdala subregions, including the medial nucleus of the amygdala, the cortical amygdala and the periamygdaloid cortex. Recent studies suggest these anterior and medial amygdala areas may play a role in sudden unexpected death in epilepsy (SUDEP), which is the leading cause of death in patients with temporal lobe epilepsy and has no known cause or treatment. Furthering our understanding of the functional and structural properties of these brain regions has strong clinical importance for these patients.