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

基本信息

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
项目类别：
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

项目摘要

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，尽管其机制尚不清楚，但我们已经知道。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。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。该实验室最近采用了“两次打击”范式，首先模仿了实践，产生了创伤表型。在新生儿重症监护病房（NICU）中，新生大鼠幼崽在生命的第一周每天都会遭受多次爪子穿刺。四个发育阶段（婴儿期、断奶期、青春期或成年期）之一的大鼠暴露于我们的初步数据显示了两组行为变化，其中首先，暴露于新生儿创伤和恐惧的断奶大鼠的发育时间进程似乎有所不同。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，其次，新生儿疼痛有相当大的亚群（~25-33%）。受试者在以后的生活中表现出恐惧调节后的冻结能力受损，这种效应在断奶后就会出现。并随着年龄的变化而增强。当前的提案进一步研究了 3 个特定的影响。在目标 1 中，我们通过检查进一步研究了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，我们进行了检查。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与 TD-番茄报告系杂交的新创建的 CRF-Cre 大鼠将用于检查。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。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。