Spinal cord ionotropic glutamate receptors function in formalin-induced nociception in preweaning rats.
Spinal cord ionotropic glutamate receptors function in formalin-induced nociception in preweaning rats.
复制标题
脊髓离子型谷氨酸受体在断奶前大鼠福尔马林诱导的伤害感受中发挥作用。
DOI：
10.1007/s00213-007-0735-x
复制
发表时间：
2007
影响因子：
3.4
通讯作者：
Barr,GordonA
中科院分区：
文献类型：
--
作者：
King,TamaraE;Barr,GordonA
RationaleNeonates respond to noxious stimuli at or before birth, but the organization of nociceptive systems changes well into postnatal life. It is unknown how nociceptive information is processed in the immature animal and, specifically, whether noxious stimulation is transmitted by glutamatergic circuits, known to play an important role in nociception in the adult. BothN-methyl-d-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors are found within the neonatal spinal cord, but in immature form, and when they become involved in pain processing in vivo is not known.ObjectivesThe objective was to determine the age-related changes in the involvement of spinal NMDA and AMPA receptors in formalin-induced nociception during early life. Because the formalin test provides a measure of immediate nociceptive responding (first phase) and of peripheral and central sensitization (second phase), a second aim was to determine if there is specificity of the effects to either phase.Materials and methodsNMDA antagonists (MK801, AP5) or an AMPA antagonist (YM872) was administered intrathecally, and pups were assessed in the formalin test behaviorally and by Fos expression within the spinal cords of 3-, 10-, and 21-day-old rats.ResultsThe NMDA antagonists attenuated formalin-induced behavioral responses at the youngest age tested with some selectivity for the second phase of responding. MK-801 did not induce motor impairment at any age. YM872 also attenuated formalin-induced nociceptive responses at all ages throughout the test session, although there was some motor impairment in the 3-day-old subjects. Spinal administration of either YM872 or MK-801 reduced Fos expression in the spinal cord at all ages.ConclusionsThese data suggest that spinal NMDA and AMPA receptor are functional and involved in formalin-induced nociception throughout development.
