Molecular identification of genes critical for vertebrate startle modulation

对脊椎动物惊吓调节至关重要的基因的分子鉴定

• 批准号: 8678297
• 负责人: Michael Granato
• 金额: $ 24万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-14 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8678297
• 关键词: Acoustics; Adaptor Protein Complex 2; Animals; Applications Grants; Attention Deficit Disorder; Behavior; Behavioral; Candidate Disease Gene; Characteristics; Cloning; Cognition Disorders; Communities; Complex; Defect; Disease; Drug abuse; Elements; Etiology; Exhibits; Funding; Gene Mutation; Gene Order; Gene Transfer Techniques; Genes; Genetic; Genetic Screening; Genome; Genotype; Grant; Human; Huntington Disease; Injection of therapeutic agent; Larva; Learning; Link; Maps; Measures; Mental Health; Messenger RNA; Molecular; Motor; Mutation; Nervous System Physiology; Nervous system structure; Neurons; Neurosciences; Nonsense Codon; Obsessive-Compulsive Disorder; Patients; Performance; Phenotype; Plasma Proteins; Positioning Attribute; Post-Traumatic Stress Disorders; Pregnancy; Process; RNA Splicing; Reflex action; Role; Schizophrenia; Sensory; Sequence Analysis; Stereotyping; Stimulus; System; Vertebrates; Zebrafish; conditioned fear; gene function; genetic manipulation; genome sequencing; in vivo; innovation; insight; kinematics; mutant; neural circuit; neuromechanism; neuropsychiatry; public health relevance; response; screening

DESCRIPTION (provided by applicant): A remarkable feature of the nervous system is its ability to adjust stereotyped behavioral responses in a context dependent manner. For example, sudden and intense acoustic stimuli evoke the evolutionarily conserved startle response. While the execution of the acoustic startle response is extremely stereotyped, response initiation is modulated in a context-dependent manner. For example, repeated presentation of a startling stimulus suppresses the startle response, representing a simple form of learning known as habituation. Similarly, response threshold and thus startle sensitivity are also modulated in a context- dependent manner, such that for fear-conditioned animals otherwise sub-threshold stimuli are now sufficient to evoke a startle response. In humans, startle modulation -as measured by habituation or startle sensitivity- is impaired in several neuropsychiatric disorders, including schizophrenia, attention deficit disorder, Huntington's disease, obsessive-compulsive disorder (OCD) as well as in patients suffering from post-traumatic stress disorders (PTSD). Despite its importance, the molecular mechanisms underlying acoustic startle modulation are poorly understood. Zebrafish show a remarkable behavioral plasticity, and we have previously shown that larvae exhibit modulation of the acoustic startle response- including sensitivity and habituation- with landmark behavioral and pharmacological characteristics. Moreover, the neural circuit elements executing the zebrafish startle response have been defined, and due to its transparency larvae are amenable to genetic and opto-genetic manipulations. Using an automated system, we conducted the first forward genetic screen in vertebrates to identify genes required for acoustic startle modulation. We identified 24 mutants with defects in startle responsiveness to sub-threshold acoustic stimuli, defects in short-term habituation, or defects in both. None of these 24 mutants exhibit any gross morphological defects or defects in startle performance. By applying whole genome sequencing to two of these mutants, we identified gene mutations in the adaptor-related protein complex 2 sigma 1 subunit (ap2s1), and in the vertebrate specific pregnancy associated plasma protein-a (papp-a), respectively. Importantly, neither of these genes has previously been implicated in regulating habituation or startle sensitivity, suggesting that many of the remaining (un-cloned) 22 mutants may encode genes with critical roles in startle modulation previously not implicated in this process. Here, we propose to apply whole genome sequencing to the remaining 22 mutants to genetically map and identify the underlying causative mutations. Combined our results will increase the scientific impact of these mutants for the entire neuroscience community by creating an unparalleled platform for integrative studies to decipher the molecular and neural mechanisms underlying 'normal' startle modulation, and provide insights into neuropsychiatric disorders associated with impaired startle modulation, such as schizophrenia, OCD and PTSD.

描述（由申请人提供）：神经系统的一个显着特征是其能够以背景方式调整刻板的行为反应。例如，突然而强烈的声学刺激引起了进化保守的惊吓反应。虽然对声学惊悚响应的执行是极为刻板印象的，但响应开始是以上下文依赖的方式调节的。例如，重复出现令人震惊的刺激会抑制惊吓反应，代表一种简单的学习形式，称为习惯。同样，反应阈值和惊吓敏感性也以上下文依赖的方式进行调节，因此，对于恐惧条件的动物，其他亚阈值刺激现在足以引起惊吓反应。在人类中，在几种神经精神疾病中，通过习惯或惊吓敏感性来衡量的惊吓调节受损，包括精神分裂症，注意力不足障碍，亨廷顿疾病，抗抑郁症（OCD）以及患有创伤后压力疾病（PTSD）的患者（PTSD）。尽管具有重要意义，但声音调制的基于的分子机制知之甚少。斑马鱼表现出显着的行为可塑性，我们先前已经表明，幼虫对声学惊吓反应的调节 - 包括具有里程碑意义的行为和药理特征，包括灵敏度和习惯性。此外，已经定义了执行斑马鱼突击反应的神经回路元件，并且由于其透明度幼虫与遗传和光遗传学操纵有关。使用自动化系统，我们在脊椎动物中进行了第一个正向遗传筛选，以识别声学惊吓所需的基因。我们确定了24个突变体，出现了对亚阈值声刺激的惊吓反应性，短期习惯的缺陷或两者的缺陷。这24个突变体中没有一个在惊吓性能中表现出任何严重的形态缺陷或缺陷。通过将整个基因组测序应用于其中两个突变体，我们在适应器相关的蛋白质复合物2 Sigma 1亚基（AP2S1）和脊椎动物特异性妊娠相关的血浆蛋白A（PAPP-A）中鉴定了基因突变。重要的是，这些基因以前都没有与调节习惯或惊吓敏感性有关，这表明许多剩余的（未连接的）22个突变体可以编码以前不涉及此过程中没有涉及的惊吓调制中具有关键作用的基因。在这里，我们建议将整个基因组测序应用于其余的22个突变体，以在遗传上绘制并识别潜在的因果突变。结合我们的结果将通过创建一个无与伦比的综合研究平台来破译“正常”惊吓调节的分子和神经机制，并提供与与暂停性障碍障碍相关的神经精神疾病相关的洞察力，从而提高这些突变体对整个神经科学社区的科学影响。