Opposing effects of cervical spinal cold block on spinal itch and pain transmission.
Opposing effects of cervical spinal cold block on spinal itch and pain transmission.
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颈椎冷阻滞对脊髓瘙痒和疼痛传递的相反作用。
DOI：
10.1097/itx.0000000000000016
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Nagamine,Masaki
中科院分区：
文献类型：
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作者：
Carstens,Earl;Carstens,MirelaIodi;Akiyama,Tasuku;Davoodi,Auva;Nagamine,Masaki
下行通路的失活增强了脊髓背角神经元对伤害性刺激的反应，但关于脊髓瘙痒传递的强直下行调制知之甚少。为研究颈髓冷阻滞对小鼠背角神经元对致痒和致痛刺激反应的影响，对戊巴比妥钠麻醉的小鼠背角浅层宽动态范围和伤害性感觉特异型神经元进行单单位记录。皮内组胺兴奋17个单位。皮内注射组胺后1分钟，冷阻断他汀类药物引起放电明显减少。组胺诱发的反应期间和之后的冷块显着低于对照组组胺诱发的反应，在没有冷块。冷阻滞对背角单位对氯喹的反应也有类似但较弱的抑制作用。26个单位响应芥子油烯丙基异硫氰酸酯（AITC），在AITC应用后1分钟开始的冷块的1分钟期间，点火进一步显著增加。活动期间冷块显着更大的AITC在没有冷块的情况下，与相同的时间段的控制响应。10个单位在冷阻断时对热伤害反应明显增强，6个单位反应减弱，18个单位无反应。冷阻滞对机械诱发反应无影响。这些结果表明，脊髓化学伤害性传递是在紧张下行抑制调制下，而脊髓伤害性传递是在相反的紧张下行易化调制下。
Inactivation of descending pathways enhanced responses of spinal dorsal horn neurons to noxious stimuli, but little is known regarding tonic descending modulation of spinal itch transmission. To study effects of cervical spinal cold block on responses of dorsal horn neurons to itch-evoking and pain-evoking stimuli, single-unit recordings were made from superficial dorsal horn wide dynamic range and nociceptive-specific-type neurons in pentobarbital-anesthetized mice. Intradermal histamine excited 17 units. Cold block stating 1 minute after intradermal injection of histamine caused a marked decrease in firing. The histamine-evoked response during and following cold block was significantly lower compared with control histamine-evoked responses in the absence of cold block. A similar but weaker depressant effect of cold block was observed for dorsal horn unit responses to chloroquine. Twenty-six units responded to mustard oil allyl isothiocyanate (AITC), with a further significant increase in firing during the 1-minute period of cold block beginning 1 minute after AITC application. Activity during cold block was significantly greater compared with the same time period of control responses to AITC in the absence of cold block. Ten units’ responses to noxious heat were significantly enhanced during cold block, while 6 units’ responses were reduced and 18 unaffected. Cold block had no effect on mechanically evoked responses. These results indicate that spinal chemonociceptive transmission is under tonic descending inhibitory modulation, while spinal pruriceptive transmission is under an opposing, tonic descending facilitatory modulation.