MRI Imaging of the Corticostriatal and Hippocampal Systems in SLI

描述（由申请人提供）：皮质纹状体系统在特定语言障碍（SLI）中的作用虽然语言的习得在人类中几乎是普遍的，但有些人比其他人更不熟练。语言习得不良是许多神经精神疾病的共同特征;然而，语言发育不良可能发生在没有明显原因的个体中，如特定语言障碍（SLI）。SLI是一种常见的神经发育障碍，发生在大约7%至8%的学龄儿童中，并持续到成年。SLI的病因尚不清楚;然而，基于新出现的行为证据，支持程序和强化学习的皮质纹状体系统可能至少部分地解释了SLI中的语言学习困难。目前，关于皮质纹状体系统，特别是皮质下结构在SLI中的作用的脑成像数据很少。因此，我们问是否有神经解剖学和神经功能的证据表明，皮质纹状体系统的重要认知学习也有助于语言的个体差异。为了解决这个问题，拟议的项目将跟踪最近的一项试点结构成像研究（SLI=12，Control=12）的结果，使用解剖磁共振成像（MRI）和扩散张量成像（DTI）检查基底神经节和丘脑的宏观结构和微观结构，这是皮质纹状体系统的主要皮质下成分。初步结果提供了强有力的证据（效应量> 0.8），表明各组之间感兴趣区域的相对体积和各向异性分数（FA）存在差异。在这个拟议的项目中，我们将首先通过将样本量增加到每组35名参与者（SLI，对照）来扩大试点结果，并将年龄范围扩大到青少年，因为青春期是大脑发生深刻变化的时期。然后，我们将比较结构和功能的连接性皮质纹状体回路之间的青少年和没有SLI使用扩散张量纤维束成像和静息态功能磁共振成像。最后，我们将研究SLI患者的脑-行为关系 以提高大脑研究结果的临床应用。我们假设SLI患者基底神经节（特别是基于我们的初步发现的壳核和丘脑核）和丘脑的宏观结构和微观结构异常。此外，SLI患者的皮质纹状体回路的白色组织改变，基底神经节与皮质区域的功能同步异常。我们还假设SLI患者在认知任务中表现不佳，这些认知任务已经被确定涉及皮质纹状体回路和大脑。 测量将预测语言状态和认知学习表现。这些目标的完成将使我们深入了解皮质纹状体系统在SLI中的作用。本研究将对语言习得中个体差异的神经机制产生积极的影响。1

DESCRIPTION (provided by applicant): The Role of the Corticostriatal System in Specific Language Impairment (SLI) Although the acquisition of language is nearly universal among humans, some are less adept than others. Poor acquisition of language is a common feature of many neuropsychiatric disorders; however, poor language development can occur in individuals who have no obvious causes as found in specific language impairment (SLI). SLI is a common neurodevelopmental disorder occurring in approximately 7 to 8% of school-age children that persists well into adulthood. The etiology of SLI is unknown; however, based on emerging behavioral evidence, the corticostriatal system that supports procedural and reinforcement learning may account for, at least in part, language learning difficulties in SLI. At this time, thre is little brain imaging data looking at the role of the corticostriatal system, subcortical structues in particular, in SLI. Thus, we have asked whether there is neuroanatomical and neurofunctional evidence showing that the corticostriatal system important to cognitive learning also contributes to individual differences in language. To address this question, the proposed project will follow up the findings from a recent pilot structural imaging study (SLI=12, Control=12) using anatomical magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) to examine the macrostructure and the microstructure of the basal ganglia and the thalamus, which are the primary subcortical components of the corticostriatal system. The pilot results provided strong evidence (effect sizes > 0.8) of differences in the relative volume and fractional anisotropy (FA) of the regions of interest between groups. In this proposed project, we will first expand on the pilot findings by increasing the sample size up to 35 participants per group (SLI, control), and extend the age range to adolescents, given that adolescence is a time of profound brain change. Then, we will compare structural and functional connectivity in the corticostriatal loops between adolescents with and without SLI by using diffusion tensor tractography and resting-state functional MRI. Last, we will examine the brain-behavior relationship in individuals with SLI to enhance the translation of brain findings to clinical applications. We hypothesize that individuals with SLI will show macrostructural and microstructural abnormality in the basal ganglia (in particular the putamen and the nucleus accumbens based on our pilot findings) and the thalamus. In addition, individuals with SLI will show altered white matter organization of the corticostriatal loops as well as abnormal functional synchrony of the basal ganglia with the cortical regions. We also hypothesize that individuals with SLI will have poor performance on cognitive tasks that have been well established to involve the corticostriatal loops, and the brain measures will predict language status and cognitive learning performance. Completion of the aims will bring insights into the role of the corticostriatal system in SLI. The proposed project wll have a positive impact on the neural mechanisms underlying individual differences in language acquisition. 1