Prefrontal function in the Shank3-deficient rat: A first rat model for ASD

描述（由申请人提供）：我们的中心假设是，包括自闭症谱系障碍在内的发育迟缓综合征导致综合脑区域突触功能的改变，从而导致异常的行为表型。我们将在转基因大鼠模型中探索这一假设。SHANK3单倍体缺陷导致神经发育变化，包括自闭症谱系障碍、注意力障碍、语言缺失或延迟、轻度至中度智力残疾和运动改变。SHANK3蛋白是突触后密度的关键结构部分。由于与小鼠相比，大鼠与人的生理更接近，因此大鼠仍然是制药行业研究新药药代动力学（PK）特性的主要选择。此外，大鼠为神经生物学、电生理学和行为学研究提供了一个更容易处理的实验模型系统，在考虑药物开发时，在进行PK研究的同一物种中进行生物分析当然是有利的。我们利用锌指核酸酶培育了一只全长大鼠Shank3基因被破坏的基因工程大鼠。这代表了有史以来第一个ASD的转基因大鼠模型，并允许我们对前额皮质进行详细的研究，前额皮质是自闭症中非常重要的区域，不容易在小鼠模型中研究。我们建议对这个模型进行详细的分析。我们计划以以下具体目标来验证我们的中心假设：1)shank3缺陷大鼠前额叶功能的行为评估；2) shank3缺陷大鼠前额叶功能电生理分析；3) shank3缺陷大鼠前额叶功能的神经病理和神经化学研究。3)在我们看来，这项研究是创新的，因为它将利用有史以来第一个ASD大鼠模型。此外，它还创新地使用了最先进的方法来理解PFC在ASD中的作用，这是ASD模型系统中尚未详细研究的关键区域。对PFC的关注也允许研究进入PFC的神经元通路，包括首次在ASD啮齿动物模型中对海马-前额叶回路进行行为神经生理学评估。我们的方法高分辨率的3D成像和神经元形态分析下降到单个脊柱的水平是值得注意的新颖。这种形式的分析将使我们能够确定在shank3缺陷大鼠中受影响的分子靶标，特别是已知与脊柱和突触大小和成熟度相关的兴奋性受体和突触蛋白的分布。最后，我们的行为分析将利用新颖的触摸屏室来详细分析PFC功能。

DESCRIPTION (provided by applicant): Our central hypothesis is that developmental delay syndromes including autism spectrum disorders lead to alterations in synaptic function in integrative brain regions that result in aberrant behavioral phenotypes. We will explore this hypothesis in a genetically modified rat model. Haploinsufficiency of SHANK3 leads to neurodevelopmental changes that include autism spectrum disorders, attentional disorders, absent or delayed speech, mild to moderate intellectual disability, and motor alterations. The SHANK3 protein forms a key structural part of the postsynaptic density. Because of the closer physiology between rats and humans as compared to mice, rats remain the primary choice of the pharmaceutical industry for studying pharmacokinetic (PK) properties of novel drugs. In addition, rats provide a far more tractable experimental model system for neurobiological, electrophysiological and behavioral studies, and it is of course advantageous, when considering drug development, that the biological assays be done in the same species where the PK studies are carried out. We have used zinc-finger nucleases to develop a genetically engineered rat with a disruption in the full-length rat Shank3 gene. This represents a first-ever genetically modified rat model for ASD and permits us to carry out detail studies in the prefrontal cortex, an area of great importance in autism, not easily studied in mouse models. We propose to carry out a detailed analysis of this model. We plan to test our central hypothesis with the following specific aims: 1) Behavioral assessment of prefrontal function in Shank3-deficient rats; 2) Electrophysiological analysis of prefrontal function in Shank3-deficient rats; and, 3) Neuropathological and neurochemical investigation of prefrontal function in Shank3-deficient rats. 3) The research is innovative, in our opinion, because it will make use of a first-ever rat model of ASD. In addition, it is innovative in the use of state-of-the art approaches to understanding the role of PFC in ASD, a key region not yet studied in detail in ASD model systems. The focus on PFC also allows for studying neuronal pathways that feed into the PFC, including the first-ever behavioral neurophysiological assessment of hippocampal-prefrontal circuitry in a rodent model for ASD. Our approach to high-resolution 3D imaging and analysis of neuronal morphology down to the level of single spine is notably novel. This form of analysis will allow us to identify molecular targets that are affected in Shank3-deficient rats, in particular, te distribution of excitatory receptors and synaptic proteins known to be linked to spine and synapse size and maturity. Finally, our behavioral analyses will make use of novel touchscreen chambers for detailed analysis of PFC function.