Mechanisms of postoperative pain in neonate : analysis using in vivo patch clamp recording from superficial dorsal horn neurons.

新生儿术后疼痛的机制：使用浅表背角神经元体内膜片钳记录进行分析。

基本信息

批准号：
15591646
负责人：
KAWAMATA Mikito
金额：
$ 2.18万
依托单位：
Sapporo Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15591646/
关键词：
Spinal dorsal horn neonate incision iniur in vivo patch-clamp recording

项目摘要

Background: The aim of the present study was to determine mechanisms of postoperative pain in neonates compared to those in adults, using the incision injury model in rats.Methods: A single activity of spinal dorsal horn wide-dyanamic-range (WDR) and high-threshold (HT) neurons, that had receptive fields (RFs) on the plantar surface of the hindpaw, was isolated from neonatal rats (postnatal days 1-14) and adult rats (8-10 weeks old) under urethane anesthesis. A 2-5 mm-long incision and 1-cm-long incision were made for neonates and for adults, respectively, in the center of the RF through the skin, fascia and muscle. Neuronal activity (spontaneous activity, RF size and responses to non-noxious and noxious stimuli applied on the center of the RF) was assessed before and 1 hr after the incision had been made. In some WDR neurons in neonate and adult rats, after the incision had been made, receptor antagonists, AP5 (50 mM) and MK-801(50 mM), and a non-NMDA receptor antagonist, CNQX (10 mM) … More , were applied into the surface of the spinal cord.Results: Responses of WDR neurons to von Frey filament stimuli (4 g and 15 g) were significantly greater in the neonatal rats than those in the adult rats. There were no significant difference in responses of WDR neurons to non-noxious or noxious stimuli between P1-P7 neonatal rats and P8-P14 neonatal rats. WDR neurons in neonatal rats often showed prolonged after-discharge following brief noxious stimuli. Subsequent spontaneous activity of WDR following incision lasted for a longer period of time in neonate rats than in adult rats after the incision had been made. Responses to non-noxious and noxious stimuli of WDR neurons significantly increased in the neonatal rats and adult rats after the incision (P < 0.01), compared to the pre-incision values. Eighty percent of HT neurons in neonatal rats began to respond to non-noxious stimuli after the incision had been made, whereas HT neurons could not respond to non-noxious stimuli in the adult rats after the incision. When AP5 and MK-801 were applied onto the spinal cord in neonatal WDR neurons 1 hr after the incision had been made, the increased responses to non-noxious and noxious stimuli almost completely abolished. However, AP5 and MK-801 did not significantly reduce the increased responses of WDR neurons to non-noxious or noxious stimuli in adult rats after the incision had been made. Application of CNQX also abolished the responses of WDR neurons to mechanical stimuli after the incision had been made. Conclusions : These findings suggest the mechanisms of postoperative pain in neonates are different from those in adults, possibly depending on the different excitatory synapse transmission through NMDA receptors in the spinal cord. Less

Background: The aim of the present study was to determine mechanisms of postoperative pain in neonates compared to those in adults, using the incision injury model in rats.Methods: A single activity of spinal dorsal horn wide-dyanamic-range (WDR) and high-threshold (HT) neurons, that had receptive fields (RFs) on the plantar surface of the hindpaw, was isolated from neonatal rats (postnatal days 1-14) and adult rats (8-10 weeks old) under urethane anesthesis.通过皮肤，筋膜和肌肉在RF的中心分别为新生儿和成年人进行了2-5毫米长的切口和1厘米长的切口。神经元活性（自发性活性，RF大小以及对RF中心应用的非毒性和有害刺激的反应）在进行切口之前和1小时之前进行了评估。在切开切口后，在新生儿和成年大鼠的一些WDR神经元中，接收器拮抗剂，AP5（50 mm）和MK-801（50 mm），以及非NMDA受体拮抗剂，CNQX（10 mm）（10毫米）…更多……更多地应用于脊髓丝的表面：spinal.neurons and neurons：4 significantly greater in the neonatal rats than those in the adult rats.在P1-P7新生大鼠和P8-P14新生儿大鼠之间，WDR神经元对非毒性或有害刺激的反应没有显着差异。 WDR neurons in neonatal rats often shown prolonged after-discharge following brief noxious stimuli.切口后，随后的WDR的赞助商活动持续了一段时间，比切开后的成年大鼠。与切入前值相比，切口后，新生大鼠和成年大鼠对WDR神经元的非氧化和有害刺激的反应显着增加。切开切口后，新生儿大鼠中有80％的HT神经元开始对无毒性的刺激作出反应，而切口后，HT神经元无法对成年大鼠的无氧刺激做出反应。切开切口后1小时的新生儿WDR神经元的脊髓上施用AP5和MK-801时，对非毒性和有害刺激的反应增加了几乎完全被废除。但是，在切开切口后，AP5和MK-801并未显着降低成年大鼠中WDR神经元对无毒理或有害刺激的反应。 Application of CNQX also abolished the responses of WDR neurons to mechanical stimuli after the incision had been made.结论：这些发现表明，新生儿术后疼痛的机制与成年人不同，可能取决于通过脊髓中NMDA接收器的不同兴奋性突触传播。较少的