Reelin, neuroendocrinology, and behaviour

Reelin、神经内分泌学和行为

• 批准号: RGPIN-2020-04600
• 负责人: Caruncho, Hector
• 金额: $ 2.04万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=740066
• 关键词: Reelin; neuroendocrinology; behaviour

The general purpose of my research program during the past 20 years has focussed on understanding the functional roles of the extracellular matrix protein Reelin and how they affect neural plasticity and behaviour: We demonstrated that Reelin was primarily expressed in GABAergic neurons in cortex and hippocampus, and how Reelin secretion in terminal dendritic fields regulated synaptic strength onto dendritic spines. We also showed how Reelin deficits in specific brain areas induced by chronic stress bring about specific behavioural and neurochemical alterations. During the past granting cycle (2015-2020) my work specifically focussed on the effects of central and peripheral Reelin in regulating the crosstalk between the immune and nervous systems. We showed that Reelin deficits bring about specific alterations not only in the brain but also in the immune system that may prime animals for the deleterious effects of chronic stress, and that some anti-inflammatory drugs rescue Reelin expression levels upon chronic stress. Recently, we observed that Reelin is differentially expressed in specific hypothalamic nuclei in the brain of male and female rats (particularly in oxytocin expressing cells in the paraventricular nucleus, but also in preoptic nuclei), that hippocampal Reelin is altered in females during pregnancy, and that these expression levels are differentially altered in the two sexes in response to chronic stress. This novel set of data allows us to hypothesize that Reelin expression in hypothalamic nuclei may differentially affect synaptic strength in specific hypothalamic circuits in male and female rodents that are directly involved in the regulation of the stress response. Our research program will examine this hypothesis at different levels. First, we will carry out a systematic evaluation of Reelin differences in male and female hypothalamus, this will include a proper identification and stereological counting of neuronal subtypes expressing Reelin. In the case of females, we will additionally study putative differences during the estrous cycle and pregnancy. Second, the effects of Reelin in hypothalamic synaptic plasticity and pituitary at the molecular level will be studied in hypothalamic synaptosomes in vitro and in cultured pituitary cells, by using a paradigm that involves adding exogenous Reelin or blocking Reelin actions by using specific anti-Reelin antibodies, and analyzing differences in the activation of Reelin signal transduction proteins, in membrane protein clustering, and in promoting protein translation in synaptosomes. Third, we will use an animal model of chronic stress to evaluate how it affects Reelin hypothalamic and pituitary expression in male and female rats, and how that relates to specific behavioural alterations, and will assay if intra-hypothalamic Reelin infusions or peripheral intravenous Reelin injections affect neurochemical and behavioural alterations induced by chronic stress.

在过去的 20 年里，我的研究计划的总体目的集中在了解细胞外基质蛋白 Reelin 的功能作用以及它们如何影响神经可塑性和行为：我们证明 Reelin 主要在皮层和海马的 GABA 能神经元中表达，以及末端树突区域中的 Reelin 分泌如何调节树突棘上的突触强度。我们还展示了慢性压力引起的特定大脑区域的 Reelin 缺陷如何导致特定的行为和神经化学改变。在过去的资助周期（2015-2020）中，我的工作特别关注中枢和外周 Reelin 在调节免疫系统和神经系统之间的串扰方面的作用。我们发现，Reelin 缺陷不仅会在大脑中引起特定的变化，还会在免疫系统中引起特定的变化，这可能会导致动物遭受慢性应激的有害影响，并且一些抗炎药物可以在慢性应激时挽救 Reelin 的表达水平。最近，我们观察到Reelin在雄性和雌性大鼠大脑的特定下丘脑核团中存在差异表达（特别是在室旁核中表达催产素的细胞中，而且在视前核中），雌性大鼠的海马Reelin在怀孕期间发生改变，并且这些表达水平在两性中因慢性应激而发生差异性改变。这组新颖的数据使我们能够假设，下丘脑核中的 Reelin 表达可能对直接参与应激反应调节的雄性和雌性啮齿类动物的特定下丘脑回路中的突触强度产生不同的影响。 我们的研究计划将在不同层面上检验这一假设。首先，我们将对男性和女性下丘脑的 Reelin 差异进行系统评估，这将包括表达 Reelin 的神经元亚型的正确识别和体视学计数。对于女性，我们将另外研究发情周期和怀孕期间的假定差异。其次，将在体外下丘脑突触体和培养的垂体细胞中研究Reelin在分子水平上对下丘脑突触可塑性和垂体的影响，通过使用涉及添加外源性Reelin或使用特异性抗Reelin抗体阻断Reelin作用的范例，并分析Reelin信号转导蛋白激活的差异， 膜蛋白聚集，并促进突触体中的蛋白质翻译。第三，我们将使用慢性应激动物模型来评估它如何影响雄性和雌性大鼠的 Reelin 下丘脑和垂体表达，以及它与特定行为改变的关系，并将测定下丘脑内 Reelin 输注或外周静脉注射 Reelin 是否影响慢性应激引起的神经化学和行为改变。