Basal Forebrain Cellular Mechanisms of Cortical Activation

皮质激活的基底前脑细胞机制

• 批准号: 8598052
• 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/8598052
• 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）： 清醒和睡眠状态如何增强信息的处理？这个问题的答案涉及大脑通过神经元振荡同步神经元组件的活性的能力，因此，正如Donald Hebb最初提出的那样，可以加强相关神经元之间的一致感知并加强相关神经元之间的突触联系。这种神经元振荡的频率，区域分布和幅度在整个睡眠效果周期内各不相同。特别是，在醒来和REM睡眠期间，γ振荡（30-80 Hz或更宽，以40 Hz为中心）是脑电图（EEG）的重要特征。这些振荡被认为对于诸如注意力，感知和记忆形成之类的大脑功能至关重要。我们小组和其他人的工作表明精神分裂症患者的前额叶和原发性（听觉和视觉）皮质的γ异常。此外，伽马缺陷是睡眠障碍，昏迷和阿尔茨海默氏病的重要特征，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疾病症状的有希望的治疗靶点。 该提案的重点是对大脑皮层的基础前脑（BF）神经元投射对皮质激活和伽马振荡的调节，因为在最近的一项研究中，BF地区的广泛病变揭示了皮质激活/γ活性的大幅度降低，导致了Coma类似COMA型的状态。尽管这种病变指出了BF的重要性，但它们并不告诉我们哪个特定的BF细胞 类型对于皮质激活很重要，BF如何受到其他大脑区域和神经递质的影响，哪些电路和神经递质将是最佳的治疗靶标。在上一个赠款周期中开发的方法和实验室使用多层次方法的强度和记录的基础上，提出的实验使用了小鼠中的综合分子，体外和体内（系统）方法，以提供对研究的神经回路的最佳理解。在第一系列实验中，新颖的光遗传光激活的离子通道将插入特定的BF亚群（含有白蛋白的胆碱能和GABA能神经元）中，以研究激活或抑制这些特定神经元细胞对皮质激活/GAMMA活性的特定神经元细胞的作用。多摄影记录将确定这些操纵对睡眠和清醒的影响。皮质局部场电位（LFP）记录将用于确切确定受睡眠剥夺和精神分裂症的三个不同皮质区域的局部γ振荡。此外，FOS免疫组织化学将用于提供对这些BF亚群的光刺激后对皮质激活的空间和细胞类型的特定分析。在我们成功使用小型干扰RNA（siRNA）之后，将使用相同的技术在BF中敲低甲氧蛋白受体，并揭示其在睡眠效果控制中的作用，从而提供可逆性，而没有经常与本构敲除的发育补偿的潜在混淆。选择性毒素MU p75--------将用于研究胆碱能BF神经元在调节觉醒和奥蛋白作用中的作用。在最后一系列实验中，我们将使用GAD67-GFP敲入小鼠，这是一种在上一个赠款周期中验证的新型基因工具，以识别皮层投射BF GABA 体外神经元。使用贴片钳记录，我们将通过胆碱能和甲状腺素能化合物揭示其调节，并确定受体和离子通道被激活。 总而言之，我们建议使用最先进的方法来识别BF投影的细胞和分子成分，以调节觉醒和皮质伽马活性。因此，我们为有针对性的疗法奠定了基础，以在影响资深人群（例如精神分裂症，阿尔茨海默氏病和睡眠障碍）等条件下提高机敏性，注意力和执行功能。