The role of lateral orbitofrontal cortex astrocytes in alcohol drinking

外侧眶额皮质星形胶质细胞在饮酒中的作用

• 批准号: 10823447
• 负责人: Abigail Riley Blasczyk
• 金额: $ 4.77万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-19 至 2026-03-18
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10823447
• 关键词: Action Potentials; Acute; Affect; Agonist; Air; Alcohol consumption; Alcohol dependence; Alcohols; Astrocytes; Bilateral; Brain region; Calcium; Calcium Signaling; Categories; Cell membrane; Cells; Chronic; Complement; Consumption; Data; Dependence; Development; Diagnosis; Dopamine D1 Receptor; Drug Addiction; Electrophysiology (science); Ethanol; Female; Fiber; Future; Glycine; Glycine Receptors; Goals; Health; Heavy Drinking; Helping Behavior; Home; Impairment; Individual; Infusion procedures; Laboratories; Lateral; Learning; Manuscripts; Measures; Membrane Potentials; Modeling; Monitor; Mus; Neurobiology; Neurons; Operative Surgical Procedures; Opsin; PMCA1 protein; Persons; Phase; Photometry; Physiology; Play; Positioning Attribute; Potassium Channel; Preparation; Process; Productivity; Quinine; Recreation; Reporter; Resistance; Rest; Role; Slice; Strychnine; Substance Use Disorder; Techniques; Testing; Therapeutic Intervention; Training; United States; Viral; Virus; Water; Withdrawal; aged; alcohol effect; alcohol exposure; alcohol research; alcohol use disorder; career; career development; dopamine D5 receptor; drinking; experimental study; glycine transporter; hippocampal pyramidal neuron; in vivo; inhibitor; insight; male; negative affect; neuron loss; neuronal excitability; novel; optogenetics; overexpression; patch clamp; prevent; redshift; research study; response; responsible research conduct; social

PROJECT SUMMARY Alcohol use disorder (AUD) is characterized by the progression from recreational drinking to uncontrollable and excessive consumption resulting in a myriad of social and neurobiological complications. The mechanisms underlying the dependence-induced escalation in drinking are not completely understood. However, a key brain region disrupted in individuals with AUD is the orbitofrontal cortex (OFC). Studies from the Woodward laboratory show that acute ethanol inhibits action potential firing of lateral orbitofrontal (lOFC) cortex pyramidal neurons. This occurs via an astrocyte-dependent process involving activation of astrocytic D1/D5 dopamine receptors and the release of glycine via reversal of the GlyT1 glycine transporter. Following chronic intermittent exposure (CIE) to alcohol, lOFC neurons become hyperexcitable and are tolerant to acute ethanol. However, the effects of CIE exposure on lOFC astrocytes and how this affects lOFC neuronal excitability are not completely understood. The overarching hypothesis of this proposal is that CIE exposure impairs lOFC astrocyte function that contributes to hyperexcitability of lOFC pyramidal neurons and the resulting dependence-induced escalation in drinking. This hypothesis will be tested with two complementary aims. Aim 1 will test the hypothesis that CIE-induced increases in lOFC neuronal excitability and loss of acute ethanol inhibition involves astrocytic calcium signaling. To test this, male and female C57BL/6J mice will receive an intra-OFC infusion of an astrocyte-selective AAV encoding either a plasma membrane calcium ATPase (PMCA) or a reporter construct (tdTomato). Following repeated cycles of CIE exposure, slice electrophysiology will be used to measure current-evoked spiking of lOFC neurons and the membrane potential of lOFC astrocytes. Training in viral infusion surgeries and astrocyte and neuron slice electrophysiology will be achieved under this aim. Aim 2 will test the hypothesis that expressing PMCA in lOFC astrocytes prevents the increases in drinking following CIE exposure. In the first study, male and female C57BL/6J mice expressing either PMCA or tdTomato localized in lOFC astrocytes will undergo baseline sessions of two-bottle choice ethanol drinking. Weekly sessions of CIE exposure will then be interleaved with test weeks of drinking. The second study will follow the same CIE paradigm with the absence of homecage drinking and will use mice expressing GCaMP6f in lOFC astrocytes and the red-shifted opsin ChrimsonR in lOFC neurons. Training in astrocyte fiber photometry and optogenetics will be achieved under this aim. The proposed research studies will be complemented by career development activities including manuscript preparation, data presentation, networking, and training in the responsible conduct of research. These studies will provide novel insight into the role of lOFC astrocytes in AUD and position me to pursue a productive career in alcohol research.

项目摘要 酒精使用障碍（AUD）的特征是从娱乐性饮酒发展到无法控制， 过度消费导致无数的社会和神经生物学并发症。的机制 依赖性引起的饮酒升级的根本原因还不完全清楚。然而，一个关键的大脑 在患有AUD的个体中被破坏的区域是眶额皮质（OFC）。伍德沃德实验室的研究 显示急性乙醇抑制外侧眶额（IOFC）皮质锥体神经元的动作电位放电。 这是通过星形胶质细胞依赖性过程发生的，该过程涉及星形胶质细胞D1/D5多巴胺受体的激活， 通过逆转GlyT 1甘氨酸转运蛋白释放甘氨酸。慢性间歇性暴露（CIE） 对于酒精，IOFC神经元变得过度兴奋并且对急性乙醇耐受。然而，CIE的影响 暴露对IOFC星形胶质细胞的影响以及这如何影响IOFC神经元兴奋性尚未完全了解。的 该提议的总体假设是CIE暴露损害了IOFC星形胶质细胞功能，其有助于 1 OFC锥体神经元的过度兴奋性和由此产生的依赖性诱导的饮酒升级。这 假设将通过两个互补的目标进行检验。目标1将检验CIE诱导的增加 在IOFC中，神经元兴奋性和急性乙醇抑制的丧失涉及星形胶质细胞钙信号传导。测试 因此，雄性和雌性C57 BL/6 J小鼠将接受OFC内输注星形胶质细胞选择性AAV编码的AAV-L1。 质膜钙ATP酶（PMCA）或报道构建体（tdTomato）。重复经 在CIE暴露的循环中，切片电生理学将用于测量IOFC神经元的电流诱发的尖峰 和IOFC星形胶质细胞的膜电位。病毒输注手术、星形胶质细胞和神经元培训 在此目标下，将实现切片电生理学。目的2将检验在细胞中表达PMCA的假设， IOFC星形胶质细胞防止CIE暴露后饮酒的增加。在第一项研究中，男性和女性 表达定位于IOFC星形胶质细胞中的PMCA或tdTomato的C57 BL/6 J小鼠将经历基线阶段 两瓶酒精饮料CIE曝光的每周会议将与测试周交错进行 喝酒第二项研究将遵循相同的CIE范式，没有家庭饮酒， 使用在IOFC星形胶质细胞中表达GCaMP 6 f和在IOFC神经元中表达红移视蛋白ChrimsonR的小鼠。 星形胶质细胞纤维光度学和光遗传学的培训将在这一目标下实现。拟议研究 研究将辅之以职业发展活动，包括手稿准备，数据 在负责任的研究行为方面进行介绍、联网和培训。这些研究将提供新的 深入了解lOFC星形胶质细胞在AUD中的作用，并使我能够在酒精研究方面从事富有成效的职业生涯。