Worms learning while intoxicated: determining the molecular mechanism and neuronal circuitry required for state dependent learning in Caenorhabditis elegans

蠕虫在醉酒时学习：确定秀丽隐杆线虫状态依赖性学习所需的分子机制和神经元回路

• 批准号: 10269897
• 负责人: Jonathan Houghton Lindsay
• 金额: $ 5.95万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-30 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10269897
• 关键词: Ablation; Affect; Alcohol dependence; Alcoholic Intoxication; Alcohols; Alleles; Animal Model; Animals; Behavior; Behavioral; Behavioral Assay; Binding; Caenorhabditis elegans; Caffeine; Cells; Chromosome Mapping; Code; Conflict (Psychology); Coupled; Coupling; Data; Dependence; Dopamine; Ethanol; Exhibits; Exposure to; Felis catus; Genes; Genetic; Genetic Models; Genetic Screening; Genomics; Glutamates; Goals; Impairment; Learning; Left; Link; Mammals; Maps; Mediating; Memory; Modeling; Molecular; Moods; Mutation; Names; Nervous system structure; Neurobiology; Neurons; Neurotransmitters; Nicotine; Octopamine; Odors; Olfactory Learning; Olfactory Pathways; Organism; Pain; Peptide Signal Sequences; Positioning Attribute; Prevention; Process; Receptor Protein-Tyrosine Kinases; Sensory; Signal Transduction; Stimulus; Study models; Testing; Work; X Chromosome; addiction; alcohol effect; alcohol exposure; alcohol misuse; alcoholism therapy; arm; behavioral response; cost estimate; drug of abuse; forward genetics; gamma-Aminobutyric Acid; genetic approach; genetic variant; genome sequencing; human subject; learned behavior; long term memory; memory process; memory recall; mutant; neural circuit; neuronal circuitry; neurotransmission; nicotine exposure; novel; olfactory stimulus; sobriety; societal costs; substance use; whole genome

Abstract Links between the neurobiology of learning and the neurobiology of addiction have been well documented. For instance, human subjects recall memories more readily while intoxicated if the memory was acquired in an intoxicated state. This is known as state dependent learning (SDL). SDL has been demonstrated in a wide variety of organisms, but little is known of the molecular mechanisms and neurocircuitry associated with SDL. In Caenorhabditis elegans (C. elegans), SDL is demonstrated by coupling the intoxicating effects of ethanol with a specific learned behavior known as olfactory adaptation; animals recall their exposure while intoxicated to an olfactory stimulus better if they are tested while intoxicated. C. elegans are an optimal model for studying the molecular underpinnings of SDL, as they have a simple 302-neuron nervous system with invariant neurocircuitry from animal to animal. The neurotransmitter dopamine is required for SDL, and animals with mutations in dopamine synthesizing genes, cat-1 and cat-2, do not learn state-dependently. These results suggest learning while intoxicated activates distinct SDL neurocircuitry that innervate and alter signaling of olfactory adaptation neurons. The ultimate goal of this work is to discover the circuit required for state dependency, and how this is regulated at the molecular level. Preliminary results show that a signaling peptide, hen-1, and a receptor tyrosine kinase, scd-2, are required for SDL. The hen-1 expressing neuron ASE-R is also required for SDL. The ASE-L neuron, which expresses almost all of the same genes as ASE-R with the exception of hen-1, is not required for SDL. In specific aim 1 I will test the sufficiency of hen-1 and scd-2 expression in ASE-R and AIA neurons respectively. Other preliminary results show octopamine deficient worms do not show SDL. The only neurons that release octopamine are RIC neurons. I will test constructs lacking the RIC neuron via genetic ablation for SDL. I have also demonstrated that SDL emerges from exposure to nicotine during olfactory learning in C. elegans. In specific aim 2 I will test for similarities in molecular mechanisms and neurocircuitry between SDL that emerge from ethanol and nicotine. I will also determine if SDL emerges in worms exposed to caffeine. Previously, a forward genetic screen was performed to find animals that are incapable of learning state-dependently during ethanol intoxication. A mutation, dubbed sdl-1, was isolated through selective screens. In specific aim 3 I will use genetic mapping and genomic sequencing to determine the molecular identity of sdl-1 and determine how the gene containing this mutation might promote SDL. Here, I hypothesize that SDL induced by ethanol intoxication has a distinct circuit that inputs onto olfactory adaptation neurocircuitry. My aims identify the molecular mechanism and neurocircuitry of this behavior by, 1) investigating hen-1/scd-2 and octopaminergic signals, 2) using other substances that may induce SDL, and 3) utilizing gene mapping to identify a novel gene associated with SDL.

抽象的 已经有充分记录的学习神经生物学与成瘾神经生物学之间的联系。为了 实例，人类受试者会更容易回忆记忆，而如果在 陶醉的状态。这被称为国家依赖学习（SDL）。 SDL已在宽阔的 各种生物种类，但对与SDL相关的分子机制和神经记录鲜为人知。 在秀丽隐杆线虫（秀丽隐杆线虫）中，通过耦合乙醇的醉酒作用来证明SDL 具有特定的学习行为，称为嗅觉适应；动物在陶醉时回想起暴露 如果在醉酒时对嗅觉刺激进行了更好的测试，则更好。秀丽隐杆线虫是研究的最佳模型 SDL的分子基础，因为它们具有简单的302-神经神经系统，不变 从动物到动物的神经循环。 SDL需要神经递质多巴胺，而具有 多巴胺合成基因CAT-1和CAT-2中的突变不依赖性地学习。这些结果 建议学习同时激活不同的SDL神经通路，从而支配和改变信号的信号 嗅觉适应性神经元。这项工作的最终目标是发现状态所需的电路 依赖性以及如何在分子水平调节。初步结果表明信号肽， SDL需要Hen-1和受体酪氨酸激酶SCD-2。 Hen-1表达神经元ASE-R是 SDL也需要。 ASE-L神经元几乎表达与ASE-R的所有相同基因 SDL不需要Hen-1。在特定目标1中，我将测试Hen-1和SCD-2的充分性 分别在ASE-R和AIA神经元中表达。其他初步结果表明章鱼胺不足 蠕虫不显示SDL。释放章鱼胺的唯一神经元是RIC神经元。我将测试构造 通过SDL的遗传消融缺乏RIC神经元。我还证明了SDL从 在秀丽隐杆线虫中，在嗅觉学习过程中暴露于尼古丁。在特定目标2中，我将测试相似之处 从乙醇和尼古丁出现的SDL之间的分子机制和神经通路。我也会 确定SDL是否出现在暴露于咖啡因的蠕虫中。以前，进行了正向遗传屏幕 在乙醇中毒期间找到无法依赖状态依赖性学习的动物。突变，称为配音 通过选择性屏幕隔离SDL-1。在特定目标3中，我将使用遗传映射和基因组 测序以确定SDL-1的分子身份，并确定含有这种突变的基因 可能会促进SDL。在这里，我假设乙醇中毒引起的SDL具有不同的电路 这输入了嗅觉适应性神经通路。我的目标确定了分子机制和 1）研究HEN-1/SCD-2和章鱼能信号的神经记录，2）使用其他 可能诱导SDL的物质，以及3）利用基因映射来识别与SDL相关的新基因。