基于下丘脑—垂体—肾上腺轴途径研究新生儿期反复操作性疼痛对行为发育的影响及其病理机制

发布时间：2018-06-08 15:14

本文选题：新生儿疼痛 + 早产儿　；参考：《南京医科大学》2014年博士论文

【摘要】：“疼痛”是指“一种不愉快的感觉和伴有实际或潜在组织损伤的情绪体验,或是一种伤害”。由于医学的进步和科学技术的发展,使得那些早产儿及重危儿在新生儿期得以存活下来。同时,对于这些未成熟儿的医学和护理的诊疗措施也包涵了未予任何镇痛处理的反复致痛性操作(painful procedures),使其在生命早期暴露于频繁的疼痛刺激中。早期疼痛刺激可导致日后的疼痛敏感性改变,行为发育迟缓和情感认知紊乱,给家庭和社会带来沉重负担。因此,正确认识并阐明新生儿早期反复操作性疼痛对儿童健康的影响及其病理机制,提高儿科医护人员对疼痛的认识,建立完善疼痛镇痛管理规程,已成为儿科学领域新的挑战。儿童的神经心理发育和行为是交织在一起的,行为发育反映了神经系统尤其是脑成熟的各种特征,各种生物因素和环境亦对大脑的解剖结构和功能产生影响。生命早期(生命最初1000天)是脑发育的关键时期,具有很大的可塑性,尤其是早产儿,其神经系统更具有易损性。历经早期反复致痛性操作可导致下丘脑-垂体-肾上腺轴(hypothalamic-pituitary-adrenal axis, HPA)的调节程序化(programming)改变,使基础和应激状态下内分泌激素如糖皮质激素水平持续增加或抑制。而海马中的糖皮质激素受体(glucocorticoid receptor,GR)作为HPA轴负反馈的调节中枢,同时又是认知、学习、记忆的重要功能区。因此,HPA轴的程序化改变伴随行为、认知、应激及内分泌系统的发育异常,这在早期经历虐待、母子分离、不良养育行为和母孕期应激等不良环境刺激致成年期表型异常改变中得到证实。但是,生后早期反复操作性疼痛如何影响发育期海马中GR的表达以及HPA轴的调控功能尚不完全清楚。基于新生儿早期经历大量致痛性操作的现状和脑发育的可塑性,本研究观察了新生儿早期操作性疼痛对婴幼儿疼痛敏感性、行为发育和外周糖皮质激素水平的影响,并应用动物模型,观察早期疼痛刺激后大鼠在青春前期及成年期行为表现,及其HPA轴程序化的改变,阐明早期疼痛刺激对儿童行为发育影响及其病理生理机制,研究结果有助于提高医务工作者对新生儿早期反复操作性疼痛对远期健康影响的认识,并为新生儿疼痛的早期预防和干预提供科学依据。第一部分新生儿期反复操作性疼痛对儿童行为发育和皮质醇的影响第一章新生儿期反复操作性疼痛对早产儿疼痛反应和皮质醇的影响目的探讨生后早期反复疼痛刺激对早产儿的疼痛行为和内分泌系统的影响。方法选取在南京医科大学附属南京儿童医院新生儿重症监护室(neonatal intensive care unit, NICU)住院的早产儿(男27例,女30例),视频记录其从入院到出院接受的所有针刺性操作,分别应用新生儿面部编码系统(Neonatal Facial Coding System, NFCS)和早产儿疼痛量表(Premature Infant Pain Profile, PIPP)评估疼痛程度。比较早产儿入院时和住院两周后血浆皮质醇水平。结果 1.住院期间,平均每个早产儿接受了104次致痛性操作。在经历40次以上的针刺性疼痛之后,疼痛操作阶段时早产儿的PIPP和NFCS评分显著高于第一次疼痛操作时(PIPP:P40=0.035; NFCS:P40=0.046),准备阶段的NFCS分值亦显著高于第一次操作的准备阶段分值(P40=0.003)。 2.早产儿入院两周后血浆皮质醇(166.3nmol/L,34.6-595.3nmol/L)较入院时(306.2nmol/L,39.1-1750.0nmol/L)显著降低(P=0.021),并与该期间经历的操作性疼痛的次数呈显著负相关(r=-0.756,P0.001)。结论 NICU的早产儿在经历反复操作性疼痛后对后续的针刺性疼痛表现出痛觉过敏,对于非疼痛处理表现出激惹现象。早产儿住院期间血浆皮质醇水平下降,并与致痛性操作次数负相关。第二章新生儿期反复操作性疼痛对幼儿行为发育及皮质醇的影响目的观察有NICU住院经历的早产儿在幼儿期的行为发育和应对新奇事物和认知挑战时皮质醇分泌模式,以及与父母养育环境的关系。方法选取出生后在南京医科大学附属南京儿童医院NICU住院的早产儿,设为早产儿组(n=25)；选取同时期出生的足月健康儿童,设为足月儿组(n=38)。2岁时通知随访。父母填写自制问卷,包括一般情况,简式育儿压力量表和2-3岁儿童行为量表；同时对幼儿进行体格测量,机械敏感性测试,Gesell智能发育检查和唾液皮质醇检测。查阅早产儿住院期间的病历资料进行相关分析。结果 1.早产儿组和足月儿组的幼儿在2岁时身高、体重和头围体格发育方面无差异(P0.05)。但早产儿组足底经皮机械敏感性阈值显著低于足月儿组(P0.05),而家长评估的幼儿疼痛敏感性则与对照组无明显差异(p=0.136)。 2.早产儿组母亲的育儿压力显著高于足月儿组,表现在育儿愁苦和亲子互动失调两方面(P0.05)。 3.早产儿组Gesell发育评估的大动作、精细动作、适应性、语言和个人社交五个能区的发言商数(development quotient, DQ)均明显低于足月儿组(P0.05),并与NICU疼痛刺激次数,母亲育儿压力呈负相关,与母亲受教育时间呈正相关(P0.05)。 4.早产儿组父母评价儿童CBCL行为量表,内向性行为的总分及社交退缩和抑郁分项目的得分均明显高于足月儿组(P0.05)。早产儿组内向性行为改变与母亲的育儿压力呈正相关(P0.05),分项目得分改变与精细动作DQ呈负相关(P0.05)。 5.基础状态和应对新奇事物和认知挑战时唾液皮质醇变化模式存在组间差异(F=4.879,P=0.035),各时间点之间同样也存在差异(F=9.671,P=0.001)。早产儿组唾液皮质醇变化与NICU经历的针刺性疼痛有关(P0.05),与母亲因素无关(P0.05)。结论与正常足月儿比较,历经NICU住院经历的早产儿幼儿期机械敏感性增加,认知水平降低,内向性行为增加,应对新奇事物和认知挑战时唾液皮质醇的变化模式和认知水平的改变均与其早期经历的反复针刺性疼痛有关。母亲受教育时间的延长可以改善早产儿的认知功能。第二部分基于下丘脑-垂体-肾上腺轴途径研究新生大鼠反复操作性疼痛致远期行为改变的病理机制目的应用大鼠动物模型,探讨生后早期反复操作性疼痛对大鼠行为发育的影响以及HPA轴反应的变化。方法选取SPF级Sprague-Dawley (SD)孕鼠,新生大鼠出生后即对雄鼠进行随机分组,疼痛组予以28G型细针迅速针刺足背,频率为每六小时一次,四足轮流,对照组则用棉签触觉刺激。造模时间从出生当天(Postnatal day1,P0)持续至出生后第7天(P7)。每周观察大鼠的机械敏感性阈值(von Frey mechanical test)变化,应用水迷宫实验,测试大鼠的空间记忆,开场、悬尾和蔗糖偏好实验测试大鼠焦虑、抑郁行为,应用生物学技术,检测皮质酮,促肾上腺皮质激素(adrenocorticotropic hormone, ACTH)海马GRmRNA口蛋白表达水平。结果 1.整个实验阶段两组大鼠体重增长无显著差异(P0.05)。P8开始,疼痛组大鼠左、右后足的机械敏感性阈值均低于对照组,并持续至P85(P0.001)。 2.水迷宫定位航行实验：P25-P29以及P88-P92训练阶段,疼痛组大鼠与对照组相比,到达平台的潜伏期无差异(P0.05)；但在P88-P92训练阶段,疼痛组大鼠的游泳速度明显快于对照组(P0.05)。在水迷宫的空间探索实验中：P30疼痛组大鼠第一次到达平台潜伏期时间、穿越平台次数以及平台搜索策略均差于对照组(P0.05),而在P93两组大鼠无差异(P0.05)。 3.P24开场测试时,疼痛组大鼠中心以及外周区域活动路程、外周区域活动速度、进入中心区域的次数均比对照组明显增加(P0.05)；P87开场测试时,疼痛组大鼠中心区域活动时间和路程、进入中心以及外周区域次数和速度均比对照组显著增加(P0.05)。P24和P87时疼痛组大鼠悬尾实验不动时间比对照组明显延长(P0.05),但蔗糖偏好实验两组无差异(P0.05)。 4.在P24及P59时,应激30分钟后对照组大鼠血清皮质酮比其他日龄水平明显增加(P0.05)；而疼痛组该趋势消失,并显著低于对照组水平(P0.05),伴有P24血清促肾上腺皮质激素(adrenocorticotropic hormone, ACTH)显著低于对照组(P0.05)；在P87时,疼痛组大鼠应激后血清皮质酮又显著高于对照组(P0.05)。 5.与对照组比较,P59疼痛组大鼠双侧肾上腺比重显著降低(P0.05)；但在P87时,双侧肾上腺比重又显著增高(P0.01)。 6.与对照组比较,P24和P45疼痛组大鼠海马GRmRNA和蛋白表达水平以及CA1区GR的平均光密度明显增高(P0.05),而在P59和P87时又显著降低(P0.05)。结论生后早期反复致痛性操作可以引起大鼠对机械刺激的敏感性持续性增高,青春前期空间记忆的保留功能受损,并使焦虑性、抑郁样行为从青春前期持续到成年期；应激后HPA轴程序化改变和异常调控。综上,我们围绕新生儿疼痛对机体近期和远期影响这一科学问题,以新生儿期和儿童期为重点,以行为学和HPA轴为研究主线,动态观察出生后NICU内的反复操作性疼痛对早产儿行为和内分泌系统的影响,证明生后早期反复操作性疼痛可以增强NICU住院期间早产儿的疼痛反应,造成住院期间及幼儿期皮质醇的重塑(reset),2岁时机械敏感性增加,认知水平降低,内向性行为的增加,母亲育儿压力增加进一步加重不良影响。进一步,应用动物模型,证明生后早期反复操作性疼痛引起机械敏感性持续性增高,从青春前期持续至成年期的行为改变；同时,机体应激反应系统重塑,HPA轴的反应呈现年龄特征改变：青春前期应激刺激后HPA轴低反应性和成年后HPA轴的过度反应。提示大脑发育关键期,反复致痛性操作导致HPA轴的程序化改变可能是日后心理行为、神经和内分泌系统发育障碍的重要病理生理机制。基于新生儿期为中枢神经系统程序化影响的关键时期,迫切需要在NICU建立新生儿疼痛管理,以避免远期行为和认知功能的损害,提高早产婴儿远期生活质量。
[Abstract]:"Pain" refers to "a feeling of unpleasant feeling and emotional experience with actual or potential tissue damage, or a kind of injury." due to the progress of medicine and the development of science and technology, the premature and critically ill infants survive in the newborn period. At the same time, the medical and nursing measures for these immature children are also taken. The repeated pain - induced manipulation (painful procedures), which has not been given to any analgesic treatment, has been exposed to frequent pain stimulation in the early life. Early pain stimulation can lead to changes in pain sensitivity, behavioral retardation and emotional cognitive disorders, and bring a heavy burden to family and society. The effect of early recurrent operational pain on children's health and its pathological mechanism, improving the understanding of pain by the pediatrics medical staff and establishing a management procedure for pain analgesia have become a new challenge in the field of Pediatrics.
The neuropsychological development and behavior of children are intertwined, and behavioral development reflects the various characteristics of the nervous system, especially the brain maturation. Various biological factors and environments also affect the anatomical structure and function of the brain. Early life (first 1000 days of life) is a critical period of brain development, with great plasticity, especially early in the early years. The nervous system is more vulnerable. After early repeated pain operation, the regulation of the hypothalamus pituitary adrenal axis (hypothalamic-pituitary-adrenal axis, HPA) regulates (programming) changes and increases or inhibits the levels of endocrine hormones such as glucocorticoids in the base and stress state. Glucocorticoid receptor (GR) is the regulatory center of negative feedback of HPA axis, and is also an important functional area of cognition, learning and memory. Therefore, the programmed changes of the HPA axis are associated with behavioral, cognitive, stressful, and endocrine dysplasia, which are in the early stage of abuse, mother and child separation, bad parenting behavior and maternal stress. However, the effect of early recurrent pain on the expression of GR in the hippocampus and the regulatory function of the HPA axis in the hippocampus of the developmental stage is not completely clear.
Based on the current situation of painful operation in early newborn and the plasticity of brain development, this study observed the effects of early operative pain on pain sensitivity, behavior development and peripheral glucocorticoid levels in infants, and used animal models to observe the behavior of early and adult rats in the early stage of pain and pain. The expression, and the changes of the programmed HPA axis, clarify the effect of early pain stimulation on children's behavioral development and its pathophysiological mechanism. The results are helpful to improve the understanding of the long-term health effects of recurrent pain in the early neonates, and provide a scientific basis for the early prevention and intervention of neonatal pain.
Part one the effect of neonatal recurrent pain on behavior development and cortisol in children
Chapter 1 the effect of neonatal recurrent pain on the pain response and cortisol in premature infants
objective
Objective to investigate the effects of early postnatal recurrent pain stimulation on pain behavior and endocrine system in preterm infants.
Method
The preterm infants (27 males and 30 females) were selected in the neonatal intensive care unit (NICU) of the Nanjing Children's Hospital of Nanjing Medical University, and all the needling operations were recorded from admission to discharge from hospital to hospital. The neonatal facial coding system (Neonatal Facial Coding System, NFCS) and preterm birth were applied respectively. Premature Infant Pain Profile (PIPP) was used to assess the pain level. Plasma cortisol levels were compared between the preterm infants and the two weeks after admission.
Result
During 1. hospitalization, the average preterm infants received 104 painful operations. After more than 40 needling pain, the PIPP and NFCS scores in premature infants were significantly higher than those of the first pain operation (PIPP:P40=0.035; NFCS:P40=0.046), and the NFCS score at the preparatory stage was significantly higher than that of the first operation. Segment value (P40=0.003).
2. the plasma cortisol (166.3nmol/L, 34.6-595.3nmol/L) was significantly lower than that of admission (306.2nmol/L, 39.1-1750.0nmol/L) after two weeks of admission to hospital (P=0.021), and was negatively correlated with the frequency of operational pain (r=-0.756, P0.001).
conclusion
The preterm infants of NICU showed hyperalgesia for subsequent acupuncture pain after repeated operation pain, and showed irritability for non pain treatment. The plasma cortisol level in premature infants declined during hospitalization and was negatively related to the number of painful operations.
The second chapter is about the effect of neonatal recurrent pain on behavior development and cortisol in young children.
objective
The relationship between the behavior development of preterm infants with NICU hospitalization and cortisol secretion patterns in response to novelty and cognitive challenges as well as the parental rearing environment were observed.
Method
The preterm infants who were hospitalized at NICU, Nanjing Children's Hospital, Nanjing Medical University, were selected as preterm infants (n=25), and a full term full term child was selected at the same time as the foot Moon Group (n=38) at the age of.2. The parents filled out the self-made questionnaire including the general situation, the simplified parenting pressure scale and the 2-3 year old child behavior scale; Physical measurement, mechanical sensitivity test, Gesell intelligence development examination and saliva cortisol test were carried out for young children. Related analysis was made on the medical records of preterm infants during hospitalization.
Result
There was no difference in height, body weight and physical development of head circumference (P0.05) at the age of 2, but the threshold of the plantar mechanical sensitivity of the preterm infants was significantly lower than that in the foot group (P0.05), but the sensitivity of the child's pain was not significantly different from that of the control group (p=0.136).
2. the pressure of parenting in the premature group was significantly higher than that in the full-term group, which was manifested in two aspects of childcare anxiety and parent-child interaction disorder (P0.05).
3. the Gesell development assessment of the preterm infant group was significantly lower than that of the full term group (development quotient, DQ), which was significantly lower than that of the full-term group (P0.05), and was negatively related to the number of NICU pain stimuli, and the mother's childbearing pressure was negatively correlated with the mother's education time (P0.05).
4. the parents of 4. preterm infants evaluated the children's behavior scale, the total score of introverted sexual behavior and the score of social withdrawal and depression were significantly higher than that of the full term infants (P0.05). The change of introversion in preterm infants was positively correlated with the parental pressure of parenting (P0.05), and the score change of the sub project was negatively correlated with the fine movement DQ (P0.05).
5. the difference in the pattern of saliva cortisol changes (F=4.879, P=0.035) was also different between the different time points (F=9.671, P=0.001). The change of saliva cortisol in the preterm group was related to the needling pain experienced by NICU (P0.05), and was not related to the mother's factor (P0.05).
conclusion
Compared with normal foot months, the mechanical sensitivity of premature infants who experienced NICU hospitalization increased, cognitive level decreased, and inward behavior increased. Changes in the patterns and cognitive levels of saliva cortisol change in response to new things and cognitive challenges were related to repeated needling pain in the early experience. Prolongation can improve the cognitive function of preterm infants.
The second part is based on the hypothalamic pituitary adrenal axis pathway to study the pathological mechanism of long-term behavioral changes in neonatal rats with repeated operative pain.
objective
Animal models were used to investigate the effects of early postoperative pain on behavior development and HPA axis response in rats.
Method
The newborn rats were randomly divided into SPF grade Sprague-Dawley (SD) pregnant rats after birth. The pain group gave 28G fine needle to the dorsum of the foot quickly. The frequency was once every six hours, four feet were rotated, and the control group was stimulated by the cotton swab. The model time lasted from the day of birth (Postnatal day1, P0) to the seventh day after birth (P7). A weekly observation was made. The mechanical sensitivity threshold (von Frey mechanical test) of rats was changed. The water maze test was used to test the rats' spatial memory, the opening, the tail and the sucrose preference test to test the rats' anxiety, depressive behavior, the application of biological techniques, the detection of corticosterone and the hippocampal GRmRNA protein protein (adrenocorticotropic hormone, ACTH) of the adrenocorticotropin (adrenocorticotropic hormone). Expression level.
Result
1. in the whole experimental stage, there was no significant difference in weight gain between the two groups (P0.05).P8. The threshold of the mechanical sensitivity of the left and right hind feet in the pain group was lower than that of the control group, and continued to P85 (P0.001).
2. water maze navigation experiment: at P25-P29 and P88-P92 training stage, there was no difference in the incubation period between the pain group and the control group (P0.05), but in the P88-P92 training stage, the swimming speed of the rats in the pain group was faster than that of the control group (P0.05). In the space exploration experiment of the water maze, the P30 pain group first arrived. The latency of platform, the number of crossing platform and platform search strategy were equally different in the control group (P0.05), but there was no difference in P93 two groups (P0.05).
During the opening test of 3.P24, the center of the pain group and the activity of the peripheral region, the frequency of the activity in the peripheral region and the number of entering the central area were significantly increased (P0.05), while the time and distance of the center area of the pain group, the times and the speed of entering the middle and peripheral regions of the pain group were significantly higher than the control group when the P87 opened the test. At the time of adding (P0.05).P24 and P87, the immobility time of the rats in the pain group was significantly longer than that in the control group (P0.05), but there was no difference in sucrose preference test between the two groups (P0.05).
4. at P24 and P59, after 30 minutes of stress, the serum corticosterone of the control group increased significantly (P0.05), but the trend of pain group disappeared, and was significantly lower than the control group (P0.05), with P24 serum adrenocorticotropin (adrenocorticotropic hormone, ACTH) significantly lower than the control group (P0.05); in P87, pain group. Serum corticosterone in rats after stress was also significantly higher than that in control group (P0.05).
5. compared with the control group, the proportion of bilateral adrenal glands in P59 pain group decreased significantly (P0.05), but at P87, the proportion of bilateral adrenal glands increased significantly (P0.01).
6. compared with the control group, the expression level of GRmRNA and protein in hippocampus and the mean light density of GR in CA1 region were significantly higher in P24 and P45 pain groups (P0.05), but decreased significantly at P59 and P87 (P0.05).
conclusion
The early repeated pain operation after birth can cause the increasing sensitivity of the rat to mechanical stimulation, the impairment of the reservation function of the prepuberty spatial memory, and the anxiety and depressive behavior from prepuberty to adulthood, and the programmed change of the HPA axis and abnormal control after stress.
To sum up, we focus on the short-term and long-term effects of neonatal pain, focusing on neonatal period and childhood, with behavioral and HPA axis as the main line, to dynamically observe the effect of recurrent operational pain on preterm infant behavior and endocrine system in postnatal NICU, and to prove that early recurrent operational pain after birth can be proved. In order to enhance the pain response of preterm infants in NICU during hospitalization, the remodeling of cortisol during hospitalization and early childhood (reset), increased mechanical sensitivity at 2 years of age, lower cognitive level, increased inward behavior, and increased parental pressure in the mother's parenting, further aggravated the adverse effects. Further, the animal model was used to prove the early recurrent operation pain. The changes in mechanical sensitivity continue to increase from prepuberty to adulthood; meanwhile, the body stress response system reshaped, the response of the HPA axis presents a change of age characteristics: the HPA axis low responsiveness and the overreaction of the adult HPA axis after prepuberty irritation. Programmed changes to the HPA axis may be the future psychological behavior, nerves and
【学位授予单位】：南京医科大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R722.1

【共引文献】