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

基本信息

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
项目类别：
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

项目摘要

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它能够以依赖于环境的方式调整刻板行为反应。例如，突然而强烈的声音刺激会引起进化上保守的惊吓反应。虽然声音惊吓反应的执行是极其刻板的，但反应的启动是以上下文相关的方式进行调制的。例如，重复出现令人震惊的刺激会抑制惊吓反应，这代表了一种称为习惯化的简单学习形式。类似地，反应阈值和惊吓敏感性也以上下文相关的方式进行调节，使得对于受恐惧条件影响的动物来说，阈下刺激现在足以引起惊吓反应。在人类中，惊吓调节（通过习惯化或惊吓敏感性来衡量）在多种神经精神疾病中受到损害，包括精神分裂症、注意力缺陷障碍、亨廷顿病、强迫症 (OCD) 以及患有创伤后应激障碍的患者（创伤后应激障碍）。尽管它很重要，但人们对声惊吓调节背后的分子机制知之甚少。斑马鱼表现出显着的行为可塑性，我们之前已经证明，幼虫表现出对声音惊吓反应的调节，包括敏感性和习惯性，具有标志性的行为和药理学特征。此外，执行斑马鱼惊吓反应的神经回路元件已经被定义，并且由于其透明性，幼虫易于进行遗传和光遗传操作。使用自动化系统，我们在脊椎动物中进行了第一次正向遗传筛选，以确定声惊吓调节所需的基因。我们鉴定了 24 个突变体，这些突变体对亚阈值声刺激的惊吓反应有缺陷，短期习惯有缺陷，或两者都有缺陷。这 24 个突变体均未表现出任何严重的形态缺陷或惊吓表现缺陷。通过对其中两个突变体进行全基因组测序，我们分别鉴定了接头相关蛋白复合物 2 sigma 1 亚基 (ap2s1) 和脊椎动物特异性妊娠相关血浆蛋白 -a (papp-a) 中的基因突变。重要的是，这些基因以前都没有涉及调节习惯或惊吓敏感性，这表明剩余的（未克隆的）22个突变体中的许多可能编码在惊吓调节中发挥关键作用的基因，而这些基因以前并未涉及这一过程。在这里，我们建议对其余 22 个突变体应用全基因组测序，以进行基因图谱和识别潜在的致病突变。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”惊吓调节背后的分子和神经机制，并提供与惊吓调节受损相关的神经精神疾病的见解，从而增加这些突变体对整个神经科学界的科学影响，例如精神分裂症、强迫症和创伤后应激障碍。