MCA Pilot PUI: From glomeruli to pollination: vertical integration of neural encoding through ecologically-relevant behavior

由人类行为驱动的生态退化及其对感觉处理的破坏是保护神经科学的一个主要焦点。近几十年来，气味污染的影响受到了越来越多的关注。农用化学气味污染已被发现扰乱大黄蜂的行为，鉴于大黄蜂在农业和自然生态系统中作为传粉者的关键作用，这一发现尤其令人震惊。这些发现表明，花卉气味的神经处理受到气味污染的影响。了解农用化学品对大黄蜂觅食行为的影响的一个障碍是，由于目前的方法本质上是统计的，所以没有具体的计算结构来表示和探索气味感知。这意味着污染不容易衡量或量化；这使得制定农业建议具有挑战性。这个项目是建立在为复杂气味(即由许多分子组成的气味)建立量化机制的早期工作的基础上，以建立代表大黄蜂气味感知的算法。已建立的“带边界化合物”(CWB)方法允许将任何两种气味之间的差异表示为角度距离，并已用于为复杂气味建立气味污染的“安全区”：20-30度范围内的污染气味被概括。下一步包括将CWB扩展为更全面的几何结构，可以准确地解释更简单的气味。这项工作将在“主要是本科院校”进行，为下一代STEM专业人员提供宝贵的研究经验。鉴于气味处理的神经生理学组织，气味分子同一性与特征的相对重要性与刺激复杂性有关，编码与身份相关的简单气味和与特征相关的复杂气味。“有边界的化合物”对复杂的混合物特别有效，因为它使用欧几里得方法量化了气味中跨分子特征分布的感觉能量的量，其中气味空间中的“维度”代表这些特征。下一个障碍是扩大这个气味空间的几何形状，以纳入分子同一性。这在逻辑上是不容易处理的，因为没有数据描绘出什么水平的气味复杂程度将初级处理输出从“身份”关联转移到“特征”关联。该项目旨在开发一种更全面的几何学，使用关联气味学习范例，并结合记录初级嗅觉处理的输入(触角)和输出(触角叶束)的神经活动。气相色谱-电触角记录将建立物种特有的气味--跨越分子身份和特征的显著特征。来自触角叶区域的尖峰分辨多单元记录将在气味信息向整合和动作中心移动时对其进行分析。在神经生理和行为水平上比较气味反应从与分子特性相关的点到分子特征的点，将形成利用刺激复杂性来塑造维度权重的扩展几何。因此，这项工作旨在建立一种通过嗅觉行为进行神经编码垂直整合的新范式。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Ecological degradation driven by human behavior and the resultant disruptions to sensory processing is a major focus of conservation neuroscience. The impacts of odor pollution have come under increasing scrutiny in recent decades. Agrochemical scent pollution has been found to disrupt bumblebee behavior, a particularly alarming finding in light of their critical role as pollinators in agricultural and natural ecosystems. These findings imply that neural processing of floral odors is impacted by odor pollution. One barrier for understanding these impacts of agrochemicals on bumblebee foraging behavior is that there are no concrete computational structures for representing and exploring odor perception, as current methods are statistical in nature. This means pollution cannot be easily measured, or quantified; which makes it challenging to develop agricultural recommendations. This project is building upon earlier work that established a quantification mechanism for complex odors (i.e. odors made up of many molecules) to establish an algorithm for representing bumblebee odor perception. The established “Compounds with Borders” (CWB) method allows the difference between any two odors to be represented as an angular distance, and has been used to establish a ‘safe zone’ of odor pollution for complex odors: polluted-odors within a 20-30 degree range are generalized. Next steps include expanding CWB into a more comprehensive geometry that can accurately account for simpler odors as well. This work will be performed at a ‘primarily undergraduate institution’, incorporating valuable research experiences for the next generation of STEM professionals.Given the neurophysiological organization of odor processing, the relative importance of molecular-identity versus -feature of odorants is linked to stimulus complexity, with encoding of simpler odors correlating with identity and more complex odors correlating with features. “Compounds with Borders” is particularly effective for complex blends because it quantifies the amount of sensory energy that is distributed across molecular features in an odor using a Euclidean approach where ‘dimensions’ in odor space represent those features. The next hurdle is to expand the geometry of this odor-space to incorporate molecular identity. This is not logistically tractable without data that delineate what level of odor complexity shifts the primary-processing output from ‘identity’ to ‘feature’ correlation. This project aims to develop a more comprehensive geometry using associative odor learning paradigms combined with recording neural activity at both the input (antennae) and output (antennal lobe tracts) from primary olfactory processing. Gas Chromatography-Electroantennographic recordings will establish a species specific odor-salience across molecular identities and features. Spike-resolved multi-unit recordings from the antennal lobe tracts will assay odor information as it moves forward to integration and action centers. Comparing the point at which odor responses shift from correlating with molecular identity to molecular feature at a neurophysiological and behavioral level will inform an expanded geometry that utilizes stimulus complexity to shape dimensional weighting. Thus, this work aims to establish a novel paradigm for vertical integration of neural encoding through behavior in olfaction.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.