Painful neonatal trauma alters subsequent fear and sensory function via changes in amygdalar CRF function

痛苦的新生儿创伤通过杏仁核 CRF 功能的变化改变随后的恐惧和感觉功能

• 批准号: 9360795
• 负责人: Michael A Burman
• 金额: $ 24.36万
• 依托单位: UNIVERSITY OF NEW ENGLAND
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9360795
• 关键词: Adolescence; Adolescent; Adult; Affect; Affective; Age; Agonist; Amygdaloid structure; Anatomy; Animals; Anxiety; Behavior; Behavioral; Biological; Cell Nucleus; Cells; Child; Cognition Disorders; Cognitive; Corticotropin-Releasing Hormone; Data; Development; Disease; FOS gene; Freezing; Fright; Functional disorder; Heterogeneity; Human; Hypersensitivity; Hypothalamic structure; Image; Immunohistochemistry; Impairment; Individual Differences; Inflammatory; Injection of therapeutic agent; Injury; Knowledge; Label; Lateral; Life; Long-Term Effects; Mental Depression; Methods; Modeling; Modernization; Molecular; Mood Disorders; Neonatal; Neonatal Intensive Care Units; Odors; Pain; Painless; Perinatal; Pharmacology; Phenotype; Predisposition; Procedures; Process; Puncture procedure; R-factor; Rattus; Reporter; Risk Factors; Sensory; Sensory Disorders; Signal Transduction; Stimulus; Stress; Structure; System; Tactile; Testing; Time; Tomatoes; Trauma; Weaning; anxiety-like behavior; behavioral outcome; conditioned fear; design; early adolescence; experimental study; infancy; midbrain central gray substance; neonatal injury; pain behavior; parabrachial nucleus; postnatal; pup; receptor; response; restraint; stressor; tool; traumatic event

Neonatal injury and trauma, such as occurs in the neonatal intensive care unit (NICU), induces life-long changes in cognitive, sensory and affective function. Although the mechanisms are as-of-yet unknown, we believe that developmental alteration of the Amygdalar CRF is likely to be a common contributing mechanism. Anatomically, CRF+ positive cells in the Central Nucleus of the Amygdala project to the ventrolateral Periaqueductal Grey and the Lateral Hypothalamus, regions involved in a variety of nocifensive behaviors. In addition, Amygdalar CRF has been shown to be critical for the acquisition or expression of both fear and pain, and the amygdala CRF system appears to be particularly sensitive to neonatal trauma. To investigate this, our lab has recently adapted a “two-hit” paradigm to produce a trauma phenotype. First, modeled after practices in the NICU, neonatal rat pups are exposed to multiple paw punctures daily for the first week of life. Second, at one of four developmental stages (infancy, weaning, adolescence or adulthood) rats are exposed to a traumatic fear conditioning procedure. Our preliminary data show two sets of behavioral changes, which appear to differ in developmental timecourse. First, weanling rats exposed to both neonatal trauma and fear conditioning show a tactile hypersensitivity following fear conditioning, that cannot be explained solely by age, neonatal trauma or fear conditioning alone. Second, a sizeable subpopulation (~25-33%) of neonatal pain subjects show impaired freezing following fear conditioning later in life. This effect is present following weaning and strengthens as a function of age. The current proposal further examines these effects over 3 specific aims. In aim 1, we further examine the behavioral heterogeneity in response to neonatal pain by examining additional painful stimuli (inflammatory paw injections), additional activating stressors (restraint) and additional behavioral outcomes (non-conditioned anxiety tests; non-reflexive pain behaviors). In aim 2, we examine whether changes in amygdalar CRF can explain the observed behavioral changes. For example, CRF expression levels following both neonatal and activating stress will be observed using PCR and unbiased stereology. Newly created CRF-Cre rats crossed with a TD-tomato reporter line will be used to examine changes in circuit anatomy, with additional labeling of FOS used to examine changes in CRF+ cell activation. Tract tracing tools will be used to determine whether distinct projections of this system are differentially affected. In aim 3, we manipulate the Amygdalar CRF system in an attempt to reverse the neonatal trauma- induced phenotype. Systemic and local injections of CRF antagonists and agonists will be used during both the neonatal and activating stress in order to reverse the hypersensitive and affective phenotypes. In addition, chemogenetic approaches can be used with CRF-Cre rats to disrupt or enhance CRF projections to specific targets. Together, these experiments will definitely test the hypothesis that neonatal trauma affects subsequent behavior via alternations in CRF signaling in the Amygdala.

新生儿损伤和创伤，例如发生在新生儿重症监护病房 (NICU) 的情况，会导致终生 认知、感觉和情感功能的变化。尽管目前尚不清楚其机制，但我们 认为杏仁核 CRF 的发育改变可能是一个常见的促进机制。 从解剖学上讲，杏仁核中央核中的 CRF+ 阳性细胞投射到腹外侧 导水管周围灰质和下丘脑外侧区参与各种伤害行为。在 此外，杏仁核 CRF 已被证明对于恐惧和疼痛的获得或表达至关重要， 杏仁核 CRF 系统似乎对新生儿创伤特别敏感。为了调查这一点，我们的 实验室最近采用了“两次打击”范例来产生创伤表型。首先，借鉴实践 在新生儿重症监护病房（NICU）中，新生大鼠幼崽在出生的第一周每天都会遭受多次爪子穿刺。第二，在 四个发育阶段（婴儿期、断奶期、青春期或成年期）之一的大鼠暴露于 创伤性恐惧调理程序。我们的初步数据显示了两组行为变化，其中 发育时间进程似乎有所不同。首先，断奶大鼠暴露于新生儿创伤和恐惧 条件反射在恐惧条件反射后表现出触觉过敏，这不能仅用年龄来解释， 新生儿创伤或单独的恐惧调节。其次，新生儿疼痛有相当大的亚群（~25-33%） 受试者在晚年的恐惧调节后表现出冰冷受损。这种效果在断奶后出现 并随着年龄的增长而增强。当前的提案进一步研究了 3 个具体的影响 目标。在目标 1 中，我们通过检查来进一步检查新生儿疼痛反应的行为异质性 额外的疼痛刺激（炎症性爪子注射）、额外的激活压力源（约束）和额外的刺激 行为结果（非条件性焦虑测试；非反射性疼痛行为）。在目标 2 中，我们检查 杏仁核 CRF 的变化是否可以解释观察到的行为变化。例如，CRF 将使用 PCR 和公正的方法观察新生儿应激和激活应激后的表达水平 体视学。新创建的 CRF-Cre 大鼠与 TD-番茄报告系杂交将用于检查 电路解剖结构的变化，并使用额外的 FOS 标记来检查 CRF+ 细胞激活的变化。 束追踪工具将用于确定该系统的不同投影是否有差异 做作的。在目标 3 中，我们操纵杏仁核 CRF 系统，试图扭转新生儿创伤—— 诱导表型。期间将使用 CRF 拮抗剂和激动剂的全身和局部注射 新生儿和激活应激，以逆转过敏和情感表型。此外， 化学遗传学方法可用于 CRF-Cre 大鼠，以破坏或增强 CRF 对特定的预测 目标。总之，这些实验肯定会检验新生儿创伤影响的假设 通过杏仁核中 CRF 信号的交替来控制后续行为。