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

描述（由申请人提供）：我们的中心假设是发育迟缓综合征（包括自闭症谱系障碍）导致整合性脑区域中突触功能的改变，从而导致异常行为表型。我们将在转基因大鼠模型中探索这一假设。SHANK 3的单倍不足导致神经发育变化，包括自闭症谱系障碍、注意力障碍、言语缺失或延迟、轻度至中度智力残疾和运动改变。SHANK 3蛋白形成突触后致密物的关键结构部分。由于与小鼠相比，大鼠和人类之间的生理学更接近，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更易处理的实验模型系统，当考虑药物开发时，在进行PK研究的相同物种中进行生物测定当然是有利的。我们已经使用锌指核酸酶来开发具有全长大鼠Shank 3基因破坏的基因工程大鼠。这代表了有史以来第一个遗传修饰的ASD大鼠模型，并允许我们对前额叶皮层进行详细研究，这是自闭症中非常重要的一个区域，在小鼠模型中不易研究。我们建议对这种模式进行详细的分析。我们计划用以下具体目标来检验我们的中心假设：1）Shank 3缺陷大鼠的前额叶功能的行为评估; 2）Shank 3缺陷大鼠的前额叶功能的电生理分析;以及，3）Shank 3缺陷大鼠的前额叶功能的神经病理学和神经化学研究。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，它在使用最先进的方法来理解PFC在ASD中的作用方面具有创新性，这是ASD模型系统中尚未详细研究的关键区域。对PFC的关注还允许研究输入PFC的神经元通路，包括首次对ASD啮齿动物模型中的前额叶-前额叶回路进行行为神经生理学评估。我们的高分辨率3D成像和分析神经元形态的方法下降到单脊柱的水平是非常新颖的。这种形式的分析将使我们能够识别Shank 3缺陷大鼠中受影响的分子靶点，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型触摸屏室对PFC功能进行详细分析。

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.