The role of microRNAs in activity-dependent cortical plasticity

描述(申请人提供)：microRNAs(MiRNAs)是进化上保守的非编码小RNA，已被证明在大脑发育和突触可塑性中发挥重要作用。大脑表达的miRNAs被预测在转录后水平上调节对皮质可塑性至关重要的多个基因的表达。剥夺一只或两只眼睛的视觉输入是研究经验依赖型皮层可塑性的经典范式。然而，感觉剥夺对小鼠视皮层miRNA表达的影响尚未被研究。本研究旨在阐明miRNAs在小鼠视皮层暗培养(DR)和单眼剥夺(MD)后突触变化中的作用。具体地说，我们将首先使用微阵列来确定在黑暗饲养或单眼剥夺后，小鼠初级视觉皮质中哪些miRNAs发生了变化。然后，我们将应用锁定核酸原位杂交和qRT-PCR来验证这些经验依赖的miRNAs的变化，更重要的是确定它们潜在的层状或细胞特异性。然后将利用慢病毒诱导的miRNAs过表达，这些miRNAs在单眼剥夺或小鼠视皮层暗饲养后减少。在体内操纵MD相关的miRNAs之后，将首先使用电生理记录和内在信号的光学成像来研究它们对经验依赖的皮质可塑性的影响。最后，将进行体内双光子成像，以确定MD和DR相关miRNAs的过度表达是否对初级视觉皮质的树突棘动力学产生影响。这项建议将确定在单眼剥夺或暗饲养后小鼠视皮层中改变的miRNAs，并探索它们在经验依赖性突触可塑性中的作用。我的重点是通过以视觉皮质发育为范式，阐明这些已经与神经精神疾病有关的新的非编码小RNA对哺乳动物皮质突触可塑性的重要性。

DESCRIPTION (provided by applicant): MicroRNAs (miRNAs) are small evolutionary conserved non-coding RNAs that have been shown to play an important role in brain development and synaptic plasticity. Brain expressed miRNAs are predicted to regulate at a posttranscriptional level the expression of multiple genes important for cortical plasticity. Deprivation of visual input from one or two eyes is a classical paradigm for studying experience-dependent cortical plasticity. However, the effect of sensory deprivation in miRNA expression in mouse visual cortex has not yet been investigated. This proposal focuses on elucidating the role of miRNAs in synaptic changes following dark rearing (DR) and monocular deprivation (MD) in mouse visual cortex. Specifically, we will first use microarrays to determine which miRNAs are altered in mouse primary visual cortex following dark rearing or monocular deprivation. We will then apply Locked nucleic acid- in situ hybridization and qRT-PCR to verify the changes in these experience-dependent miRNAs and more importantly determine their potential laminar or cellular specificity. Lentiviral induced overexpression of miRNAs that are reduced following monocular deprivation or dark rearing in mouse visual cortex will then be utilized. Following in vivo manipulation of MD-related miRNAs, electrophysiological recordings and optical imaging of intrinsic signals will first be used to study their effect on experience-dependent cortical plasticity. Lastly, in-vivo two-photon imaging will be carried out to determine if overexpression of both MD and DR related miRNAs has an effect in dendritic spine dynamics of primary visual cortex. This proposal will identify miRNAs that are altered in mouse visual cortex following monocular deprivation or dark rearing and explore their role in experience-dependent synaptic plasticity. My focus is to elucidate the importance of these novel small non coding RNAs that have already been linked to neuropsychiatric disease for mammalian cortical synaptic plasticity by using visual cortex development as a paradigm.