Cell Identity Determination In Cerebral Cortex

描述(申请人提供)：这项建议的主要目标是阐明神经发生的基本细胞机制，并了解控制神经干细胞存活和增殖能力的机制。大脑皮质的正常发育对正常的认知功能至关重要，需要准确地完成一系列发育步骤。大脑皮质发育异常可导致智力低下、癫痫、学习障碍和脑性瘫痪。在这项资助的前一期，我们研究了小头畸形症(小脑皮质)的几个原因的机制，这些研究表明，小头畸形症基因在控制神经增殖方面发挥着重要作用，在某些情况下，控制神经细胞的命运。在这项资助中，我们建议分析在发育中的和成人大脑中调节神经干细胞的干细胞生态位。这些实验对于阐明大脑中神经干细胞的基本控制具有深远的意义，并对提高我们控制这些干细胞的能力具有潜在的治疗意义。我们建议研究胚胎脑脊液(ECSF)蛋白质组对神经发生的调控。尽管已经确定了许多调控神经发生的基因，但启动和终止神经发生的全球控制是完全未知的。我们的初步数据表明，eCSF在发育和成年期对所有已知的神经干细胞的纤毛进行沐浴，对皮质外植体和培养的神经干细胞的神经发生具有指导作用，不同外植体的年龄和eCSF的年龄不同。我们建议分析eCSF对体外培养的神经干细胞和大脑皮质外植体的影响，以及eCSF(和成人脑脊液)对大脑皮质外植体和体外培养的神经干细胞影响的年龄相关性变化。我们进一步建议鉴定和验证调节皮质神经发生的eCSF成分。在胚胎发育的最后几天，神经发生的速度和性质变化很快，这表明全球线索也在变化。我们的初步数据显示，在同一时间段内，脑脊液的功能效应和蛋白质组成发生了巨大的变化。为了研究这一点，我们将使用MALDI-MS和Western分析来确定皮质神经发生期间脑脊液蛋白质组的组成，并分析脑脊液关键成分的浓度变化。我们还将研究eCSF的特定蛋白对神经发生的调控。我们已经确定IGF2是一种特异性生长因子，在神经发生过程中在eCSF中高表达，在出生后表达下调。我们建议分析获得和丢失IGF2和其他特定的eCSF蛋白对神经发生的影响。 与公共健康相关：大脑皮层(大脑中控制记忆和意识等高级功能的部分)的适当发育对正常认知功能至关重要，需要准确完成一系列发育步骤。大脑皮质发育异常可导致智力低下、癫痫、学习障碍和脑性瘫痪。这项拨款中提出的实验对于阐明大脑中神经干细胞(将成为神经元的细胞)的基本控制具有深远的意义，并在提高我们控制这些干细胞的能力方面具有潜在的治疗意义。

DESCRIPTION (provided by applicant): The major goal of this proposal is to elucidate basic cellular mechanisms of neurogenesis, and to understand the mechanisms that control the ability of neural stem cells to survive and proliferate. Proper development of the cerebral cortex is essential for normal cognitive function, and requires the precise completion of a series of developmental steps. Abnormalities of cerebral cortical development can cause mental retardation, epilepsy, learning disorders, and cerebral palsy. In the previous funding period of this grant we studied of the mechanisms of several causes of microcephaly (small cerebral cortex), these studies suggest that microcephaly genes play important roles in the control of neural proliferation and, in some cases, the control of neural cell fate. In this grant we propose to analyze the stem cell niche that regulates neural stem cells in the developing, and the adult, brain. These experiments have profound significance for elucidating the fundamental control of neural stem cells in the brain, and have potential therapeutic implications in improving our ability to control these stem cells. We propose to study the regulation of neurogenesis by the embryonic cerebral spinal fluid (eCSF) proteome. Although many genes that regulate neurogenesis have been identified, the global controls that initiate and terminate neurogenesis are completely unknown. Our preliminary data suggest that eCSF, which bathes the cilia of all known neural stem cells both during development and in adulthood, shows instructive effects on neurogenesis in cortical explants and cultured neural stem cells that differ with the age of the explant, and the age of the eCSF. We propose to analyze the effects of eCSF on cerebral cortical explants in vitro and cultured neural stem cells in vitro and age-related changes in the effects of eCSF (and adult CSF) on cortical explants and cultured neural stem cells. We further propose to identify and verify eCSF components that regulate cortical neurogenesis. The pace and nature of neurogenesis changes rapidly in the last days of embryonic development suggesting that global cues change as well. Our preliminary data show that the functional effects and protein composition of CSF changes dramatically during this same time-frame. To study this we will use MALDI-mass spectroscopy and Western analysis to determine the composition of the CSF proteome during the period of cortical neurogenesis, and analyze changes in concentration of key CSF components. We will also study the regulation of neurogenesis by specific proteins of the eCSF. We have identified IGF2 as one specific growth factor that is highly expressed in eCSF during neurogenesis, and down regulated postnatally. We propose to analyze the effects of gain and loss IGF2 and other specific eCSF proteins on neurogenesis. PUBLIC HEALTH RELEVANCE: Proper development of the cerebral cortex (the portion of the brain that controls higher functions such as memory and consciousness) is essential for normal cognitive function, and requires the precise completion of a series of developmental steps. Abnormalities of cerebral cortical development can cause mental retardation, epilepsy, learning disorders, and cerebral palsy. The experiments proposed in this grant have profound significance for elucidating the fundamental control of neural stem cells (cells that will become neurons) in the brain, and have potential therapeutic implications in improving our ability to control these stem cells.