Prefrontal impairment with stress- NE receptor subtype mechanisms.

摘要-背外侧前额叶皮层（dlPFC）介导的工作记忆和自上而下的控制，但 在急性或慢性压力下受损，并且在大多数精神障碍中功能失调。压力暴露增加 去甲肾上腺素（NE）释放，通过β-AR和α1-AR加强杏仁核的情绪反应，但 通过α1-AR减弱dlPFC，而β-AR的作用尚不清楚。在此基础上，提出了广义α1-AR β-AR拮抗剂哌唑嗪和β-AR拮抗剂普萘洛尔用于治疗创伤后应激障碍 （PTSD）。然而，哌唑嗪和心得安并不总是有效的，研究结果表明，一些亚型， α1-AR和β-AR的结合可能有益于PFC，因此阻断所有亚型的拮抗剂可能适得其反。 本研究将首次对α1-AR（α1A-AR、α1B-AR、α1D-AR）和β-AR（β1-AR、β2-AR）进行研究。 用多标记免疫荧光定位α1-AR，β3-AR）亚型在恒河猴dlPFC中的作用， 锥体细胞、GABA能中间神经元、星形胶质细胞和小胶质细胞上的AR和β-AR亚型，以及免疫电镜 以揭示超微结构位置，例如在突触前释放位点或在第III层dlPFC中的树突棘上。我们 将使用离子电渗结合单单位记录的dlPFC神经元在猴子执行一个工作 记忆任务，以确定α1-AR和β-AR亚型的刺激如何改变任务相关的神经元放电， 他们的第二信使行动。我们还将使用α1-AR和β-AR亚型的全身给药 阻断应激诱导的工作记忆缺陷的选择性拮抗剂，并测试选择性试剂是否 比目前使用的非选择性药物哌唑嗪或普萘洛尔更有效， 低剂量的选择性更强的拮抗剂可以恢复认知，副作用更少。目标1将描述 α1-AR亚型的作用，检查它们的定位（Aim 1A），在dlPFC中的生理作用（Aim 1B）， 以及轻度急性应激对工作记忆表现的影响（Aim 1C）。初步数据显示 α1A-AR亚型显著减少工作记忆相关的dlPFC神经元放电，选择性 α1A-AR拮抗剂可有效阻断应激诱导的认知缺陷，提示其是一种上级的治疗策略。 治疗学目的2将表征β-AR亚型，检查它们的定位（目的2A），生理学 在dlPFC中的作用（目的2B），以及在轻度急性应激期间对工作记忆表现的影响（目的2B）。 2C）。初步数据表明，β1-AR亚型显著减少工作记忆相关的dlPFC 选择性β1-AR拮抗剂阻断应激诱导的认知缺陷。在心肌中， “战斗或逃跑”应激反应是由电压门控Cav1.2钙通道的β1-AR开放介导的 （由CACNA 1C编码），我们的初步数据表明，灵长类dlPFC中有害的β1-AR作用 涉及类似的行为，有助于解释为什么CACNA 1C的功能获得性突变会增加精神疾病的风险。 dlPFC功能受损的疾病，包括PTSD。鉴定α1-AR和β-AR的亚型， dlPFC功能受损将有助于设计更有效的治疗方法来治疗与压力有关的精神障碍。

Abstract- The dorsolateral prefrontal cortex (dlPFC) mediates working memory and top-down control, but is impaired by acute or chronic stress, and is dysfunctional in most mental disorders. Stress exposure increases norepinephrine (NE) release, which strengthens amygdala emotional responses via (β-AR and α1-AR, but weakens the dlPFC via α1-AR, while the role(s) of β-AR are unknown. Based on this work, the general α1-AR antagonist, prazosin, and β-AR antagonist, propranolol, are used to treat Post-Traumatic Stress Disorder (PTSD). However, prazosin and propranolol are not always effective, and findings suggest that some subtypes of α1-AR and β-AR may benefit PFC, and thus antagonists that block all subtypes may be counterproductive. The proposed research will perform the first study of α1-AR (α1A-AR, α1B-AR, α1D-AR) and β-AR (β1-AR, β2- AR, β3-AR) subtype actions in rhesus monkey dlPFC, using multiple label immunofluorescence to localize α1- AR and β-AR subtypes on pyramidal cells, GABAergic interneurons, astrocytes and microglia, and immunoEM to reveal ultrastructural locations, e.g. at pre-synaptic release sites or on dendritic spines in layer III dlPFC. We will use iontophoresis coupled with single unit recordings of dlPFC neurons in monkeys performing a working memory task to determine how stimulation of α1-AR and β-AR subtypes alters task-related neuronal firing, and their second messenger actions. We will also use systemic administration of α1-AR and β-AR subtype selective antagonists to block stress-induced working memory deficits, and test whether selective agent(s) are more potent and efficacious than the currently used, nonselective agents, prazosin or propranolol, and whether low doses of more selective antagonists can restore cognition with fewer side effects. Aim 1 will characterize the roles of α1-AR subtypes, examining their localization (Aim 1A), physiological actions in dlPFC (Aim 1B), and effects on working memory performance during a mild, acute stressor (Aim 1C). Preliminary data indicate that the α1A-AR subtype markedly reduces working memory-related dlPFC neuronal firing, and that a selective α1A-AR antagonist potently blocks stress-induced cognitive deficits, suggesting a superior strategy for therapeutics. Aim 2 will characterize β-AR subtypes, examining their localization (Aim 2A), physiological actions in dlPFC (Aim 2B), and effects on working memory performance during a mild, acute stressor (Aim 2C). Preliminary data indicate that the β1-AR subtype markedly reduces working memory-related dlPFC neuronal firing, and that a selective β1-AR antagonist blocks stress-induced cognitive deficits. In heart muscle, the “fight or flight” stress response is mediated by β1-AR opening of voltage-gated Cav1.2 Ca2+ channels (encoded by CACNA1C), and our preliminary data indicate that detrimental β1-AR actions in primate dlPFC involve similar actions, helping to explain why gain-of-function mutations in CACNA1C increase risk of mental disorders with impaired dlPFC function, including PTSD. Identifying the subtypes of α1-AR and β-AR that impair dlPFC function will help the design of more effective therapies for stress-related mental disorders.