Basal Forebrain Cellular Mechanisms of Cortical Activation

皮质激活的基底前脑细胞机制

• 批准号: 8413399
• 负责人: Robert W McCarley
• 金额: --
• 依托单位: VA BOSTON HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2015-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8413399
• 关键词: Acoustic Stimulation; Action Potentials; Affect; Alzheimer' s Disease; Anterior; Attention; Auditory; Auditory area; Basic Science; Binding; Biological Models; Brain; Brain Stem; Brain region; Carbachol; Cations; Cerebral cortex; Cholinergic Agonists; Coma; Data; Development; Disease; Electroencephalogram; Elements; Exhibits; Financial compensation; Fluorescence; Frequencies; Funding; Future; Genetic; Grant; Halorhodopsins; Immunohistochemistry; In Vitro; Injection of therapeutic agent; Ion Channel; Ions; Knock-in Mouse; Knock-out; Laboratories; Lesion; Light; Measures; Mediating; Memory; Methodology; Methods; Military Personnel; Molecular; Mus; Muscarinic M3 Receptor; Muscarinics; Neurons; Neurotransmitter Receptor; Neurotransmitters; Parvalbumins; Patients; Perception; Polysomnography; Population; Procedures; REM Sleep; RNA; Receptor Activation; Regulation; Research; Role; Schizophrenia; Sensory; Series; Sleep; Sleep Deprivation; Sleep Disorders; Sleep Wake Cycle; Slice; Small Interfering RNA; Sodium; Symptoms; Synapses; System; Techniques; Testing; Toxin; Veterans; Viral Vector; Visual Cortex; Wakefulness; Work; alertness; basal forebrain; basal forebrain cholinergic neurons; base; cell assembly; cell type; cholinergic; cholinergic neuron; cingulate cortex; executive function; gamma-Aminobutyric Acid; hypocretin; improved; in vivo; information processing; neural circuit; novel; novel strategies; optogenetics; orexin B receptor; patch clamp; programs; receptor; recombinase; research study; response; sleep regulation; therapeutic target; tool; transcriptional coactivator p75; voltage clamp

DESCRIPTION (provided by applicant): How do the states of wakefulness and sleep enhance the processing of information? The answer to this question involves the ability of the brain to synchronize the activities of assemblies of neurons by means of neuronal oscillations so that salient pieces of information are bound together in coherent percepts and synaptic connections between related neurons are strengthened, as originally proposed by Donald Hebb. The frequency, regional distribution and amplitude of such neuronal oscillations vary across the sleep-wake cycle. In particular, gamma oscillations (30-80 Hz or broader, centered on 40 Hz) are a prominent feature of the electroencephalogram (EEG) during waking and REM sleep. These oscillations are thought to be essential for brain functions such as attention, perception, and memory formation. Work from our group and from others has demonstrated gamma abnormalities in prefrontal and primary sensory (auditory and visual) cortices in schizophrenic patients. Furthermore, gamma deficits are a prominent feature of sleep disorders, coma, and Alzheimer's disease, other conditions prevalent in veterans and military personnel. Modulation of gamma oscillations thus represents a promising therapeutic target to treat symptoms of these disorders. This proposal focuses on the modulation of cortical activation and gamma oscillations by the basal forebrain (BF) neuronal projections to the cerebral cortex, since, in a recent study, extensive lesions of the BF region revealed dramatic reductions in cortical activation/gamma activity leading to a coma-like state. While such lesions point to the importance of BF, they do not tell us which specific BF cell types are important for cortical activation, how BF is influenced by other brain regions and neurotransmitters, and which circuits and neurotransmitters would be optimal treatment targets. Building on the methodologies developed in the previous grant cycle and following our laboratory's strength and track record of using a multilevel approach, the proposed experiments use integrated molecular, in vitro, and in vivo (systems) methods in mice to provide optimal understanding of the neural circuits studied. In the first series of experiments novel 'optogenetic light- activated ion channels will be inserted into specific BF subpopulations (cholinergic and GABAergic neurons containing parvalbumin) to study the effect of activating or inhibiting these specific neuronal cell types on cortical activation/gamma activity. Polysomnographic recordings will determine the effect of these manipulations on sleep and wakefulness. Cortical local field potential (LFP) recordings will be used to gain a precise determination of local gamma oscillations in three different cortical regions affected by sleep deprivation and exhibiting abnormalities in schizophrenia. In addition, Fos immunohistochemistry will be used to provide a spatial and cell-type specific analysis of cortical activation following light stimulation of theseBF subpopulations. Following our successful use of small interfering RNA (siRNA) in the brainstem, the same technique will be used to knockdown orexin receptors in the BF and reveal their role in sleep-wake control, providing reversibility without the potential confound of developmental compensation often seen with constitutive knockouts. The selective toxin mu p75-saporin will be used to investigate the role of cholinergic BF neurons in the regulation of wakefulness, and the effect of orexins. In the last series of experiments we will use GAD67-GFP knock-in mice, a novel genetic tool validated in the previous grant cycle, to identify cortically projecting BF GABA neurons in vitro. Using patch-clamp recordings we will reveal their modulation by cholinergic and orexinergic compounds and determine the receptors and ion channels activated. In summary, we propose to use state-of-the-art methods to identify the cellular and molecular components of the BF projections to the cortex modulating wakefulness and cortical gamma activity. We thereby lay the groundwork for targeted therapies to improve alertness, attention, and executive function in conditions that affect the Veteran population such as schizophrenia, Alzheimer's disease and sleep disorders.

描述（由申请人提供）： 清醒和睡眠状态是如何增强信息处理的？这个问题的答案涉及到大脑通过神经元振荡同步神经元集合活动的能力，这样显著的信息片段就以连贯的感知结合在一起，相关神经元之间的突触连接得到加强，正如唐纳德·赫布最初提出的那样。这种神经元振荡的频率、区域分布和振幅在整个睡眠-觉醒周期中变化。特别是，伽马振荡（30-80 Hz或更宽，以40 Hz为中心）是清醒和REM睡眠期间脑电图（EEG）的突出特征。这些振荡被认为是大脑功能，如注意力，感知和记忆形成所必需的。我们小组和其他人的工作已经证明，精神分裂症患者的前额叶和初级感觉（听觉和视觉）皮质存在伽马异常。此外，伽马缺陷是睡眠障碍、昏迷和阿尔茨海默病的突出特征，其他疾病在退伍军人和军事人员中普遍存在。因此，γ振荡的调节代表了治疗这些病症的症状的有希望的治疗靶点。 这项建议的重点是调制皮质激活和伽玛振荡的基底前脑（BF）神经元投射到大脑皮层，因为在最近的一项研究中，广泛的病变BF区域显示皮质激活/伽玛活动的显着减少，导致昏迷样状态。虽然这种病变表明BF的重要性，但它们并不能告诉我们具体是哪种BF细胞。 类型对于皮层激活很重要，BF如何受到其他大脑区域和神经递质的影响，以及哪些回路和神经递质将是最佳治疗目标。基于上一个资助周期开发的方法，并遵循我们实验室的实力和使用多层次方法的记录，拟议的实验在小鼠中使用集成的分子，体外和体内（系统）方法，以提供对所研究的神经回路的最佳理解。在第一系列实验中，将新型光遗传学光激活离子通道插入特定BF亚群（含有小清蛋白的胆碱能和GABA能神经元）中，以研究激活或抑制这些特定神经元细胞类型对皮质激活/γ活性的影响.多导睡眠图记录将确定这些操作对睡眠和觉醒的影响。皮质局部场电位（LFP）记录将用于精确测定受睡眠剥夺影响并表现出精神分裂症异常的三个不同皮质区域的局部伽马振荡。此外，Fos免疫组织化学将被用来提供一个空间和细胞类型的特定分析皮质激活后，这些BF亚群的光刺激。在我们成功地在脑干中使用小干扰RNA（siRNA）之后，将使用相同的技术来敲除BF中的食欲素受体并揭示它们在睡眠-觉醒控制中的作用，提供可逆性而没有通常在组成性敲除中看到的发育补偿的潜在混淆。选择性毒素μ p75-皂草素将用于研究胆碱能BF神经元在觉醒调节中的作用以及食欲素的作用。在最后一系列的实验中，我们将使用GAD 67-GFP基因敲入小鼠，一种在前一个资助周期中验证的新型遗传工具，来鉴定皮质投射的BF GABA。 体外培养的神经元。使用膜片钳记录，我们将揭示它们的调制胆碱能和食欲素能化合物，并确定受体和离子通道激活。 总之，我们建议使用国家的最先进的方法来确定的BF预测皮质调节觉醒和皮质γ活动的细胞和分子组成部分。因此，我们为靶向治疗奠定了基础，以改善精神分裂症，阿尔茨海默病和睡眠障碍等影响退伍军人群体的条件下的警觉性，注意力和执行功能。