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: 10176523
• 负责人: Michael A Burman
• 金额: $ 28.14万
• 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 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10176523
• 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; Exposure to; FOS gene; Freezing; Fright; Functional disorder; Heterogeneity; Human; Hypersensitivity; Hypothalamic structure; Image; Immunohistochemistry; Impairment; Individual Differences; Inflammatory; Injections; 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; Rattus; Reporter; Risk Factors; Sensory; Sensory Disorders; Signal Transduction; Stimulus; Stress; Structure; System; Tactile; Testing; Time; Tomatoes; Trauma; Weaning; anxiety-like behavior; behavioral outcome; comorbidity; conditioned fear; design; designer receptors exclusively activated by designer drugs; early adolescence; experimental study; infancy; midbrain central gray substance; neonatal injury; neonatal period; 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.

新生儿伤害和创伤，如发生在新生儿重症监护病房(NICU)，会导致终生 认知、感觉和情感功能的变化。尽管机制到目前为止还不清楚，但我们 相信杏仁核CRF的发育改变可能是共同的致病机制。 杏仁中央核内CRF+阳性细胞向腹外侧方投射 中脑导水管周围灰质和下丘脑外侧，这两个区域参与了各种突触行为。在……里面 此外，杏仁核CRF已被证明对恐惧和疼痛的获得或表达都是关键的， 杏仁核CRF系统似乎对新生儿创伤特别敏感。为了调查这件事，我们 实验室最近采用了一种“两次打击”的范例来产生创伤表型。首先，仿照 NICU新生大鼠幼崽在出生的第一周每天都会受到多次爪子穿孔的影响。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 创伤性恐惧条件反射程序。我们的初步数据显示了两组行为变化， 似乎在发育的时间进程上有所不同。首先，暴露在新生儿创伤和恐惧中的断奶大鼠 条件反射在恐惧条件反射之后表现出一种触觉超敏，这不能仅仅用年龄来解释， 新生儿创伤或恐惧条件反射。其次，相当大的新生儿疼痛亚群(约25%-33%) 受试者在以后的生活中表现出恐惧条件反射后的冰冻受损。这种影响在断奶后表现出来。 并随着年龄的增长而增强。目前的提案进一步审查了这些影响，具体有3个 目标。在目标1中，我们进一步检验了新生儿疼痛反应的行为异质性。 额外的疼痛刺激(炎性爪子注射)、额外的激活性应激源(约束)和其他 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的变化能否解释观察到的行为变化。例如，CRF 使用聚合酶链式反应和无偏倚方法观察新生儿应激和激活应激后的表达水平 体视学。新培育的CRF-CRE大鼠将与TD-番茄报告系杂交，用于检测 电路解剖的变化，并使用额外的FOS标记来检查CRF+细胞激活的变化。 将使用轨迹追踪工具来确定该系统的不同投影是否存在差异 受影响。在目标3中，我们操纵杏仁核CRF系统，试图扭转新生儿的创伤- 诱导表型。全身和局部注射CRF拮抗剂和激动剂 新生儿和活动性应激以逆转过敏性和情感性表型。此外, 化学遗传学方法可用于CRF-CRE大鼠以干扰或增强CRF对特定基因的投射 目标。总而言之，这些实验肯定会检验新生儿创伤影响 随后的行为通过杏仁核中CRF信号的变化来实现。