Characterizing the primary olfactory subregions of the human amygdala

人类杏仁核的几个亚区接受嗅球的直接投射，但功能性的 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 阐明了其中一些杏仁核嗅觉亚区在调节嗅觉引导的社会交往中的作用 和接近/避免行为。然而，嗅觉的投射有显著的差异。 种间的鳞茎到杏仁核。例如，在啮齿动物中，杏仁内侧核接收高度致密的 副嗅球的纤维。与之形成鲜明对比的是，人类完全缺乏辅助嗅觉系统。 在主要嗅球投射的特定杏仁核目标上还有其他明显的差异。 在物种之间，尽管这些靶点在人类中还没有得到很好的表征，进一步突显了 在这一领域需要进行人体研究。这项提案的目标是描述解剖学和 人类杏仁核嗅觉投射的功能特性。我们将采取多方面的 方法，结合功能神经成像，电生理和刺激，这将加强 我们研究结果的重复性和严谨性。目标1的目标是从解剖学和功能上定位 人类杏仁核的初级嗅觉皮质区域。在结构层面上，我们将使用一种新的多- 激发扩散加权成像序列将嗅觉投射定位到杏仁核亚区。在 在功能层面，我们将使用静息功能磁共振结合k-均值聚类算法来分割杏仁核 基于不同的全脑功能连接配置文件的子区域，以及与事件相关的功能磁共振成像 定位杏仁核对气味反应的亚区。目标2的目标是阐明DISTINCT 嗅觉中的杏仁核亚区。我们将使用事件相关的功能磁共振成像来获得高分辨率 在嗅觉任务中来自杏仁核的多变量信号。目标3的目标是评估 杏仁核亚区在嗅觉中的必要性。我们将使用颅内脑电技术来 在临床医生提供的、临床处方的、破坏性的过程中测量不同的嗅觉感知决定 电刺激直接进入人类杏仁核。拟议的研究将提供详细的 一组正在研究中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、杏仁皮质和杏仁周围皮质。近期 研究表明，这些杏仁体前部和内侧区域可能在儿童猝死中起作用。 癫痫(SUDEP)，这是颞叶癫痫患者的主要死亡原因，没有 已知的原因或治疗。加深我们对这些物质的功能和结构性质的理解 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.