Neuroimmune modulation of neuronal function during cocaine conditioning

项目摘要 病理性物质使用障碍是一种公共健康危机，会导致巨大的发病率和死亡率。 对于受苦的病人和对整个社会的不可估量的代价。对可卡因和其他精神刺激剂上瘾 在这种疾病负担中占很大比例，目前这些患者的治疗 由于缺乏任何FDA批准的药物疗法而受到限制。尽管我们的工作取得了重大进展 理解多巴胺能、谷氨酸能和细胞内信号级联反应在脑出血模型中的改变 兴奋剂使用障碍，努力开发旨在治疗兴奋剂使用障碍的药物 不成功。越来越多的人认识到神经免疫相互作用在正常大脑功能中的作用 和可塑性，以及神经精神疾病的病理生理学。小胶质细胞，一种常驻免疫 中枢神经系统的细胞，与神经元相互作用，修剪突触，并产生可以改变的神经营养因子 突触可塑性和行为。我们最近发现粒细胞集落刺激因子(G-CSF)是 一种细胞因子，在长期吸食可卡因后，血液和大脑中的含量会增加。全身注射G-CSF 促进条件性场所偏好的形成，增强自我管理可卡因的动力。 此外，G-CSF增强可卡因对即刻早期基因c-Fos的诱导，并增强多巴胺 从腹侧被盖区释放到伏隔核(NAC)。有趣的是，G-受体- 脑脊液仅在NAC的小胶质细胞上表达。在这项提案中，我们将利用体内的尖端技术 成像技术，直接可视化和询问这种小胶质细胞调节器对模式的影响 神经活动编码可卡因的给药和寻找。在目标1中，我们将在d1中记录钙信号 和D2在活动期经G-CSF或赋形剂处理的动物的NAC内表达中等刺突神经元 可卡因自我给药或在寻找毒品的任务中。假设D1和D2的表达群体 神经元已经被证明在编码奖赏刺激方面具有相反的作用，这些实验将 提供关于G-CSF如何改变神经活动模式之间的平衡的关键信息 两个离散的细胞群体。在目标2中，我们将通过以下方式测试小胶质细胞中G-CSF信号的因果性质 使用转基因小鼠模型，仅在小胶质细胞中删除G-CSF受体，并测量 行为和神经回路的改变。总之，这些实验将描述神经回路的变化 通过小胶质细胞诱导G-CSF信号转导并阐明小胶质细胞信号转导机制 控制与可卡因相关的行为。

Project Summary Pathological substance use disorders are a public health crisis leading to tremendous morbidity and mortality for afflicted patients and incalculable costs to society at large. Addiction to cocaine and other psychostimulants accounts for a significant proportion of this burden of disease, and treatment of these patients is currently limited by the lack of any FDA-approved pharmacotherapies. Despite significant advances in our understanding of the dopaminergic, glutamatergic, and intracellular signaling cascades altered in models of stimulant use disorders, efforts to develop medications aimed at treating stimulant use disorder have been unsuccessful. There is a growing appreciation for the role of neuroimmune interactions in normal brain function and plasticity as well as in the pathophysiology of neuropsychiatric diseases. Microglia, the resident immune cells of the CNS, interact with neurons, prune synapses, and produce neurotrophic factors that can alter synaptic plasticity and behavior. We have recently identified granulocyte-colony stimulating factor (G-CSF) as a cytokine that is increased in blood and brain following prolonged cocaine. Systemic injections of G-CSF enhance the formation of conditioned place preference and enhance motivation to self-administer cocaine. Additionally, G-CSF potentiates cocaine induction of the immediate early gene c-Fos and enhances dopamine release from the ventral tegmental area into the nucleus accumbens (NAc). Interestingly, the receptor for G- CSF is expressed exclusively on microglia in the NAc. In this proposal we will utilize cutting-edge in vivo imaging technology to directly visualize and interrogate the effects of this microglial modulator on patterns of neuronal activity that encode cocaine administration and seeking. In Aim 1 we will record calcium signals in D1 and D2 expressing medium spiny neurons in the NAc of animals treated with G-CSF or vehicle during active cocaine self-administration or during a drug seeking task. Given that the D1 and D2 expressing populations of neurons have been shown to have opposing effects on encoding rewarding stimuli, these experiments will provide crucial information as to how G-CSF is shifting the balance of patterns of neural activity between these two discrete cell populations. In Aim 2, we will test the causal nature of G-CSF signaling through microglia by using a transgenic mouse model that deletes the G-CSF receptor exclusively in microglia and measure behavioral and neural circuit changes. Together, these experiments will characterize the neural circuit changes induced by G-CSF signaling through microglia and elucidate the mechanisms by which microglial signaling controls cocaine-associated behavior.