兴奋性氨基酸介导脊髓伤害性信息传递

Mediation of Excitatory Amino Acids in Synaptic Transmission of Spinal Nociceptive Information

ＮＭＤＡ和非ＮＭＤＡ受体广泛存在于猫脊髓背角神经元上，并参与介导伤害性信息传递；ＮＭＤＡ受体主要介导皮肤的伤害性传入，非ＮＭＤＡ受体则主要介导肌肉和内脏的伤害性传入；皮肤和肌肉的伤害性传入分别诱发释放更多的门冬氨酸和谷氨酸可能是这种差别的主要原因之一；ＮＭＤＡ受体的不同调节位点在伤害性信息传递中有密切的协同作用；兴奋性氨基酸和Ｐ物质及其受体在介导和调制伤害性信息传递中的相互作用可以分别发生在神经元的胞体和树突水平。

NMDA and non NMDA receptors exist extensively on the spinal dorsal horn neurons and are involved in mediating neurotransmission of spinal nociceptive information. NMDA receptor mainly mediates the neurotransmission of cutaneous nociceptive information, while non NMDA receptor mainly contributes to the neurotransmission of muscular and visceral nociceptive information. One of the main reasons for this difference may be that the cutaneous and muscular nociceptive inputs induced more releases of aspartate and glutamate, respectively. There are co operative interactions among the regulatory sites within NMDA receptor channel complex in modulation of spinal nociception. The co operative interaction between excitatory amino acids and substance P in modulation of spinal nociceptive information may occur on both the body and the dendrites of the nociceptive neuron.