Role of GABA on circadian and homeostatic regulation of sleep

GABA 对昼夜节律和睡眠稳态调节的作用

• 批准号: 9128731
• 负责人: Horacio O De La Iglesia
• 金额: $ 33.8万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9128731
• 关键词: Absence Epilepsy; Activity Cycles; Address; Adult; Animal Disease Models; Animals; Autistic Disorder; Automobile Driving; Brain; Brain region; Caregivers; Cell Nucleus; Cells; Childhood; Circadian Rhythms; Cognitive deficits; Dependovirus; Disease; Effectiveness; Epilepsy; Exons; Generalized seizures; Generations; Genes; Genetic Recombination; Goals; Grant; Health; Hypothalamic structure; Impairment; Interneurons; Lead; Light; Modeling; Mus; Mutation; Nature; Neurons; Nucleic Acid Regulatory Sequences; Patients; Phase; Phenotype; Physiologic pulse; Process; Quality of life; REM Sleep; Regulation; Research; Rest; Role; SCN1A protein; Seizures; Site; Sleep; Sleep Deprivation; Sleep Disorders; Slow-Wave Sleep; Symptoms; Syndrome; Testing; Thalamic structure; Time; Vasoactive Intestinal Peptide; Viral; Virus; base; circadian pacemaker; conditional mutant; gamma-Aminobutyric Acid; loss of function mutation; mouse model; mutant; neuromechanism; non rapid eye movement; promoter; recombinase; relating to nervous system; response; sleep abnormalities; sleep regulation; sleep regulatory center; suprachiasmatic nucleus; voltage

 DESCRIPTION (provided by applicant): Animals carrying a heterozygous loss-of-function mutation in the Scn1a gene (Scn1a+/- mice), which encodes a subunit of the voltage-gated Na+ channel NaV1.1, show deficits in both homeostatic regulation of sleep and circadian regulation of rest-activity cycles. The NaV1.1 channel is the primary voltage-gated Na+ channel in adult GABAergic interneurons and its reduced activity results in a decrease of GABAergic tone, suggesting that sleep regulatory deficits in Scn1a+/- mice emerge from reduced GABAergic activity. However, Scn1a+/- mice are a model of a severe form of epilepsy known as Dravet syndrome (DS) and, as DS patients, show not only dysregulation of sleep but also generalized seizures. Epileptic activity complicates the interpretation of sleep disorders in DS, as sleep regulatory deficits could be the result of sleep disruption by seizures or of seizure-associated neural damage. Our hypothesis is that sleep disorders in DS are the consequence of reduced GABAergic tone within sleep regulatory centers that is independent of the presence of seizures. To address this hypothesis, we propose to conditionally target the Scn1a+/- mutation to specific neurons and brain regions. Specific Aim 1 will determine whether sleep abnormalities in global Scn1a+/- mice emerge from the effect of the mutation specifically on GABAergic neurons. We will target the Scn1a+/- mutation to these cells using an Scn1alox/- mouse and a Cre driver mouse line that targets GABAergic neurons throughout the brain, and will assess the integrity of the circadian and homeostatic regulation of sleep in these mutants. This approach will unequivocally determine whether sleep regulatory deficits in Scn1a+/- mice are the result of reduced NaV1.1 channel activity within GABAergic cells or whether non- GABAergic cells that express the channel also contribute to this phenotype. Specific Aim 2 will target the Scn1a+/- mutation to cells in the suprachiasmatic nucleus (SCN), the site of the central circadian pacemaker that regulates sleep. Viruses expressing Cre recombinase, targeting either all SCN cells or specifically vasoactive intestinal polypeptide (VIP)-containing cells, will be injected wihin the SCN of Scn1alox/+ mice. We will also target the mutation to the SCN VIPergic cells by crossing Scn1alox/+ mice with a mouse line in which the VIP promoter drives the expression of Cre. Because VIP neurons are essential for the integrity of the SCN oscillatory network, we expect that these VIP-specific Scn1a+/- mutants will show similar effects to mutants in which all SCN cells are targeted. Specific Aim 3 will virally target the Scn1a+/- mutation to the reticular nucleus of the thalamus (RNT), which is essential for the generation of slow-wave sleep and spindles during non- REM sleep, both compromised in Scn1a+/- mice. None of the conditional mutant approaches in Aims 1 and 2 is expected to induce seizures, offering a unique opportunity to assess the effect of reduced NaV1.1 channel activity in sleep regulatory regions, in the absence of seizures. We predict that the conditional targeting of the Scn1a+/- mutation to the SCN and RNT will lead to deficits in circadian and homeostatic regulation of sleep, respectively. These results would provide direct support for the role of the NaV1.1 channel within these brain regions in the regulation of sleep. They would also directly support our hypothesis that both circadian and homeostatic sleep deficits in DS emerge from seizure-independent reduced GABAergic activity in specific brain regions, providing new avenues for the treatment of sleep disorders in DS.

 描述（应用程序提供）：在SCN1A基因（SCN1A +/-小鼠）中携带杂合丧失功能突变的动物，它编码了电压门控的Na+通道NAV1.1的亚基，在睡眠稳态调节和昼夜节律调节中的静止状态均显示了定义的定义。 NAV1.1通道是成年GABA能中间神经元中的主要电压门控通道及其活性降低会导致GABA能张力的降低，这表明睡眠调节性在SCN1A +/-小鼠中定义了降低的GABA能活性。然而，SCN1A +/-小鼠是一种严重形式的癫痫症模型，称为Dravet综合征（DS），并且作为DS患者，不仅显示出睡眠失调，而且还显示出广义性癫痫发作。癫痫活性使DS中睡眠障碍的解释复杂化，因为睡眠调节性可能是癫痫发作或癫痫发作相关的神经元损害的睡眠破坏的结果。我们的假设是，DS中的睡眠障碍是睡眠调节中心中GABA能张力降低的结果，而与癫痫发作的存在无关。为了解决这一假设，我们建议将SCN1A +/-突变靶向特定的神经元和大脑区域。具体的目标1将确定全局SCN1A +/-小鼠的睡眠异常是否从突变对GABA能神经元的影响中出现。我们将使用SCN1A +/-突变将SCN1A +/-突变靶向这些细胞，并使用SCN1ALOX/ - 小鼠和CRE驱动小鼠系列，该小鼠靶向整个大脑的GABA能神经元，并评估这些突变体中昼夜节律和稳态调节的完整性。这种方法将明确确定SCN1A +/-小鼠中的睡眠调节性是否是降低了GABA能细胞内NAV1.1通道活性的结果，还是表达通道表达该通道的非GABA能细胞也会对这种表型有助于。特定的目标2将靶向SCN1A +/-突变源于Suparchiasmatic Nuitus（SCN）的细胞，SCN（SCN）是调节睡眠的中央昼夜节奏起搏器的部位。表达CRE重组酶的病毒，靶向所有SCN细胞或特定的血管活性肠多肽（VIP）细胞，将向SCN1ALOX/+小鼠的SCN注射。我们还将通过将SCN1ALOX/+小鼠与小鼠线跨越SCN抗癌细胞的突变靶向，其中VIP启动子在其中驱动CRE的表达。由于VIP神经元对于SCN振荡网络的完整性至关重要，因此我们希望这些VIP特异性的SCN1A +/-突变体将显示与所有SCN细胞靶向的突变体相似的作用。特定的目标3实际上将靶向SCN1A +/-突变to thalamus（RNT）的网状核，这对于在非REM睡眠过程中生成慢波睡眠和纺锤体至关重要，这两者都在SCN1A +/-小鼠中受到损害。目标1和2中的条件突变方法都没有诱发癫痫发作，提供了独特的机会来评估在没有癫痫发作的情况下，在睡眠调节区域中NAV1.1通道活动降低的影响。我们预测，SCN1A +/-突变对SCN和RNT的条件靶向将分别在昼夜节律和稳态调节中定义。这些结果将直接支持NAV1.1通道在这些大脑区域在睡眠调节中的作用。他们还将直接支持我们的假设，即昼夜节律睡眠均来自DS中的DS中，与癫痫发作无关降低的特定脑区域的Gabaergic活性降低，为DS治疗睡眠障碍的治疗提供了新的途径。