The Striatal Circuitry Underlying Autistic-Like Behaviors

描述（由申请人提供）：自闭症谱系障碍（asd）包括一组神经发育障碍，大约110名儿童中有1名受到影响（CDC, 2009）。asd的特点是存在三个主要症状：社会互动缺陷、重复或刻板行为和语言发育异常。尽管最近的人类遗传学研究已经确定了几个ASD候选基因，但涉及这些疾病病因的一般机制和脑回路在很大程度上仍未被破译。对一个特定基因的研究可能有助于理解自闭症背后难以捉摸的疾病机制。Shank3是突触后密度的支架蛋白，是Shank家族蛋白中唯一在纹状体中富集的成员。由于大量研究将Shank3的中断与受影响的人类患者联系起来，该基因已成为asd的一个有吸引力的候选基因。最近，我们的实验室产生并鉴定了一种新的Shank3B突变小鼠，并发现了社会互动缺陷和重复行为的存在。对这些异常原因的进一步调查确定了皮质纹状体突触传递缺陷以及其他几种纹状体神经元畸变。该项目的长期目标是了解Shank3B突变小鼠asd样行为背后的神经回路，以确定治疗干预的潜在靶点。我假设纹状体回路缺陷是导致

DESCRIPTION (provided by applicant): Autism spectrum disorders (ASDs) comprise a group of neurodevelopmental disorders that affect approximately 1 in 110 children (CDC, 2009). ASDs are characterized by the presence of three cardinal symptoms: social interaction deficits, repetitive or stereotyped behaviors, and abnormal language development. Though recent human genetics studies have identified several ASD candidate genes, the general mechanisms and brain circuitry involved in the etiology of these disorders remain largely undeciphered. The study of one gene in particular may be helpful in understanding the elusive disease mechanisms underlying ASDs. Shank3 is a scaffolding protein of the post-synaptic density that is the only member of the Shank family of proteins to be enriched in the striatum. Due to the multitude of studies connecting disruptions of Shank3 to affected human patients, this gene has become an attractive candidate gene for ASDs. Recently, our laboratory generated and characterized a novel Shank3B mutant mouse and discovered the presence of social interaction deficits and repetitive behaviors. Further investigation into the cause of these abnormalities identified defects in cortico-striatal synaptic transmission as well as several other striatal neuron aberrations. The long-term goal of this project is to understand the neural circuitry underlying the ASD-like behaviors in Shank3B mutant mice in order to identify potential targets for therapeutic intervention. I hypothesize that defective striatal circuitry plays a causative role in these abnormal behaviors. To directly test this hypothesis, I will generate a Shank3B conditional knockout mouse. I will then use this mouse to remove Shank3 exclusively from the striatum with the expectation that this region-specific ablation will recapitulate the repetitive behaviors and social interaction deficits found in the Shank3B mutant mice. To further probe the influence of defective striatal circuitry on these behaviors, I will then generate direct- and indirect pathway-specific Shank3 knockout mouse lines and analyze their social interactions and stereotyped behaviors. If successful, these studies could provide the first direct evidence for striatal dysfunction as a mechanism for repetitive behaviors and abnormal social interaction behaviors in an animal model of autism.