Gene therapy against conditioned fear

描述（由申请人提供）：很明显，反复暴露于压力会增加发展和表达人类恐惧和焦虑障碍症状的风险，但对这种情况发生的机制知之甚少。 许多研究表明，海马体受到慢性压力的深刻影响。因此，患有恐惧和焦虑障碍的患者通常表现出海马活动减少，以及海马依赖性学习和记忆障碍。相反，据报道，这些患者表现出杏仁核活性的增加和杏仁核依赖性学习和记忆的增强。由于杏仁核在先天性和后天习得的恐惧中起着至关重要的作用，因此该区域可能是恐惧和焦虑症的基础压力相关变化的所在地。然而，几乎没有研究表明慢性压力对杏仁核的影响。 在拟议的研究中，我们将使用功能测量（行为和突触可塑性）来表征大鼠杏仁核中与应激相关的变化，其中海马神经元中与应激相关的损伤已有很好的记录。我们假设，慢性应激对海马功能产生负面影响的方案将促进杏仁核功能沿着这些相同的措施，从而模拟人类应激与恐惧和焦虑障碍之间的关系。 然后，我们将研究两种基因治疗干预在逆转与压力相关的恐惧增强方面的疗效。我们将产生应激诱导的单纯疱疹-1病毒扩增子，旨在表达活性依赖性钾通道（Kv 1. 1）、钙依赖性钾通道（SK）、酶11-β-羟基类固醇脱氢酶-2（11B）或反式显性负性糖皮质激素受体（Td）。我们将研究这些蛋白在两个杏仁核区域（基底外侧复合体或中央核）在应激过程中过度表达的影响，以确定是否减少神经元兴奋性（Kv1.1和SK）或糖皮质激素（11B或Td）在杏仁核的作用在应激过程中恢复正常的功能，通过行为和电生理措施。这些研究将是第一批探索基因治疗在治疗精神疾病模型中的可行性的研究，并将为慢性应激影响杏仁核功能的机制提供重要和新颖的见解。

DESCRIPTION (provided by applicant): It is clear that repeated exposure to stress increases the risk of developing and expressing symptoms of human disorders of fear and anxiety, however little is known about the mechanisms by which this occurs. Numerous studies have shown that the hippocampus is profoundly affected by chronic stress. Accordingly, patients with disorders of fear and anxiety often exhibit reduced hippocampal activity, and impairments in hippocampus-dependent learning and memory. In contrast, such patients are reported to exhibit increases in amygdala activity and enhancement of amygdala-dependent learning and memory. Because the amygdala plays an essential role in both innate and learned fear, this region may be a locus of stress-related changes that underlie fear and anxiety disorders. However, almost no work has examined the impact of chronic stress on the amygdala. In the proposed research, we will characterize stress-related changes in the amygdala in rats, using functional measures (behavior and synaptic plasticity) for which stress-related impairments in hippocampal neurons are well documented. We hypothesize that a regimen of chronic stress that negatively impacts hippocampal function across multiple measures will facilitate amygdala function along those same measures, thereby modeling the relationship between stress and disorders of fear and anxiety in humans. We will then examine the efficacy of two gene therapeutic interventions in reversing stress-related enhancement of fear. We will generate stress-inducible herpes simplex-1 viral amplicons designed to express an activity-dependent potassium channel (Kv1. 1), a calcium-dependent potassium channel (SK), the enzyme 11-beta-hydroxysteroid dehydrogenase-2 (11B), or a transdominant negative glucocorticoid receptor (Td). We will examine the impact of overexpressing these proteins in two amygdaloid regions (the basolateral complex or central nucleus) during stress to determine whether reducing either neuronal excitability (Kv1.1 and SK) or the actions of glucocorticoids (11B or Td) in the amygdala during stress restores normative function across behavioral and electrophysiological measures. These studies will be among the first to probe the feasibility of gene therapy in treating models of psychiatric disorders, and will provide important and novel insights into the mechanisms by which chronic stress impacts amygdala function.