Gene therapy against conditioned fear

描述(申请人提供)：很明显，反复暴露在压力下会增加出现和表现出人类恐惧和焦虑障碍症状的风险，但人们对这种情况发生的机制知之甚少。 大量研究表明，海马体深受慢性压力的影响。因此，患有恐惧和焦虑障碍的患者通常表现出海马体活动减少，以及海马体依赖的学习和记忆障碍。相比之下，据报道，这类患者杏仁核活动增加，杏仁核依赖学习和记忆增强。因为杏仁核在先天恐惧和后天恐惧中都扮演着重要的角色，这一区域可能是导致恐惧和焦虑症的压力相关变化的中心。然而，几乎没有研究过慢性压力对杏仁核的影响。在这项拟议的研究中，我们将使用海马神经元中与应激相关的损伤的功能指标(行为和突触可塑性)来表征大鼠杏仁核中应激相关的变化。我们假设，一种通过多种措施对海马体功能产生负面影响的慢性应激疗法，将沿着这些相同的措施促进杏仁核功能，从而模拟人类应激与恐惧和焦虑障碍之间的关系。 然后，我们将检验两种基因治疗干预在逆转与压力相关的恐惧增强方面的有效性。我们将产生压力诱导的单纯疱疹病毒1型病毒扩增，旨在表达活性依赖的钾通道(KV1)。1)、钙依赖钾通道(SK)、酶11-β-羟基类固醇脱氢酶-2(11B)或跨显性负性糖皮质激素受体(TD)。我们将研究应激期间杏仁核两个区域(基底外侧复合体或中央核)这些蛋白的过度表达的影响，以确定在应激期间降低杏仁核中神经元的兴奋性(Kv1.1和SK)或糖皮质激素(11B或TD)的活动是否恢复了行为和电生理指标的正常功能。这些研究将是第一批探索基因疗法治疗精神障碍模型的可行性的研究之一，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.