Glial dependent modulation of depressive like behaviors

描述(申请人提供)：睡眠异常与许多精神疾病并存，尽管睡眠障碍是抑郁症的原因还是后果尚不清楚。在临床人群中，一整晚的睡眠剥夺可以立即起到抗抑郁作用，尽管信号通路尚不清楚。我们认为，腺苷是睡眠剥夺的抗抑郁作用的基础，因为i)腺苷调节睡眠，ii)睡眠剥夺使腺苷升高，iii)在睡眠障碍的抑郁症患者中发现了腺苷转运体和代谢酶的单核苷酸多态。我们证明了星形胶质细胞对急性睡眠剥夺的行为反应有贡献。我们有条件地在星形胶质细胞中表达囊泡蛋白的SNARE结构域，以抑制胞吐作用，导致细胞外腺苷减少，评估指标为神经元A1受体(A1R)的基础激活减少，非快速眼动(NREM)睡眠期间慢波活动(SWA)减少，以及睡眠剥夺后恢复睡眠受损。我们假设，急性睡眠剥夺的抗抑郁效应是通过星形胶质细胞衍生的腺苷作用于神经元A1受体而实现的。目的1：我们将检验这一假设，即星形胶质细胞对睡眠稳态的调节有助于睡眠剥夺的抗抑郁效应。我们将确定整晚(12小时)的睡眠剥夺是否会导致抗抑郁样反应，然后使用dnSNARE小鼠将询问星形细胞睡眠稳态是否需要介导抑郁样反应。目的2：我们将验证A1受体需要介导睡眠剥夺的抗抑郁样效应的假说。我们将确定12h的睡眠剥夺是否导致A1R的激活增强，并利用A1R拮抗剂的中枢递送和A1R基因敲除(A{1}R[-/-])小鼠，我们将确定睡眠剥夺的抗抑郁效应是否需要A1R。目的3：我们将验证中枢A1R的持续(12h)药理激活将产生抗抑郁样作用的假说。我们将通过脑室注射A1R激动剂(i.c.v.)并将询问该受体通路的激活是否产生抗抑郁的类似作用。目的4：我们将确定额叶皮质在睡眠剥夺的抗抑郁效应中的作用。我们将扩大初步的c-fos免疫反应性研究，并使用新型Tet tag转基因小鼠，使c-fos活性神经元能够进行GFP标记，以识别睡眠剥夺激活的额叶皮质神经元。最后，我们将用dnSNARE病毒转导额叶皮质星形胶质细胞，并询问区域特异性转导是否抑制睡眠剥夺的抗抑郁效应。识别睡眠剥夺的抗抑郁作用的潜在信号通路有可能为未来的发展提供帮助。 以神经胶质为基础的疗法可立即缓解抑郁症。

DESCRIPTION (provided by applicant): Sleep abnormalities are co-morbid with many psychiatric conditions though whether sleep disorders are a cause or consequence of depression is unclear. A total night of sleep deprivation has immediate antidepressive actions in the clinical population, although the signaling pathway is unknown. We propose that adenosine underlies the antidepressive effects of sleep deprivation because i) adenosine regulates sleep, ii) sleep deprivation elevates adenosine, and iii) single nucleotide polymorphisms in adenosine transporters and a metabolic enzyme have been identified in patients with depression with disturbed sleep. We demonstrated that astrocytes contribute to the behavioral responses to acute sleep deprivation. We conditionally expressed the SNARE domain of a vesicle protein in astrocytes to impair exocytosis resulting in reduced extracellular adenosine, as assessed by reduced basal activation of neuronal A1 receptors (A1R), reduced slow wave activity (SWA) during non-rapid eye movement (NREM) sleep and impaired recovery sleep following sleep deprivation. We hypothesize that the antidepressive effects of acute sleep deprivation are mediated by astrocyte-derived adenosine acting on neuronal A1 receptors. Aim 1: We will test the hypothesis that astrocytic modulation of sleep homeostasis contributes to antidepressive effects of sleep deprivation. We will determine whether a total night (12h) of sleep deprivation leads to antidepressive like effects, then using dnSNARE mice will ask whether the astrocytic sleep homeostat is required to mediate depressive-like responses. Aim 2: We will test the hypothesis that A1 receptors are required to mediate the antidepressive-like effects of sleep deprivation. We will determine whether 12h of sleep deprivation leads to enhanced activation of A1R and using central delivery of A1R antagonists and A1R knockout (A{1}R[-/-]) mice we will determine whether antidepressive-like effects of sleep deprivation require A1R. Aim 3: We will test the hypothesis that sustained (12h) pharmacological activation of central A1R will produce antidepressive like effects. We will deliver A1R agonists intracerebroventricularly (i.c.v.) and wil ask whether the activation of this receptor pathway yields antidepressive like effects. Aim 4: We will determine the role of frontal cortex in contributing to antidepressive effects of sleep deprivation. We will expand preliminary c-fos immunoreactivity studies and the use of novel Tet Tag transgenic mouse that enables GFP-labeling of c-fos active neurons to identify sleep deprivation activated neurons of the frontal cortex. Finally, we will virally transduce frontal corex astrocytes with dnSNARE and ask whether region specific transduction inhibits antidepressive effects of sleep deprivation. The identification of a signaling pathway underlying antidepressive like effects of sleep deprivation has the potential to for the future development of glial-based therapeutics for the immediate relief of depression.