NOCICEPTOR-DRIVEN DORSAL HORN NEURONS IN LUMBAR SPINAL-CORD OF CAT
NOCICEPTOR-DRIVEN DORSAL HORN NEURONS IN LUMBAR SPINAL-CORD OF CAT
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DOI：
10.1016/0304-3959(76)90042-7
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发表时间：
1976-01-01
期刊：
影响因子：
7.4
通讯作者：
OGAWA, H
中科院分区：
文献类型：
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作者：
CERVERO, F;IGGO, A;OGAWA, H
在氯醛糖麻醉的猫的腰髓细胞外记录单个背角神经元。L1冷阻滞用于提供可逆性脊髓化。通过记录微电极上的Pontamine天蓝电泳沉积标记背角中的单位的位置。L6节段足腹外侧表面有清晰的躯体定位表现。在L6背角边缘区（板I）记录的46个单位中，有35个只能由小传入纤维的齐射和足部皮肤的伤害性刺激兴奋，并被称为3类细胞。其余11个单位也可以兴奋敏感的皮肤机械敏感传入单位，他们是2类单位。根据传入纤维对特定伤害感受器驱动神经元的兴奋性，可将其分为2个亚类。3（a）类仅由A δ激发。皮肤传入神经和3类（B）的A δ。和C皮肤传入。后者中的一些人也对A. δ感到兴奋。腓肠肌外侧神经的C类传入纤维。当通过自然刺激测试时，所有3类细胞都被有害的机械刺激兴奋，但只有3（B）单位通过加热皮肤被有效地兴奋。3（B）单位中的这种放电可以通过电刺激大的（II组）皮肤有髓鞘传入纤维来抑制，并且在由A δ诱发的反应中可以产生类似的效果。和C传入齐射。另外的抑制通过电刺激较慢的髓鞘化皮肤（A Δ）来实现。或组III）传入纤维。脊髓标本中3类细胞的兴奋性更高，但强直下行抑制弱于2类细胞明显相似的下行强直抑制。结果进行了讨论，参照疼痛机制。
Single dorsal horn neurons were recorded extracellulary in the lumbar spinal cord of cats anesthetized with chloralose. Cold block at L1 was used to provide reversible spinalization. The location of the units in the dorsal horn was marked by the electrophoretic deposition of pontamine sky blue from the recording microelectrode. There was a clear somatotopic representation of the ventrolateral surface of the foot in the L6 segment. Of the 46 units recorded in the marginal zone of the L6 dorsal horn (lamina I), 35 could only be excited by volleys in small afferent fibers and by noxious stimulation of the skin in the foot regions, and were termed class 3 cells. The remaining 11 units could also be excited by sensitive cutaneous mechanosensitive afferent units; they were class 2 units. The specific nociceptor-driven neurons could be divided into 2 subclasses on the basis of their excitability by afferent fibers. Class 3 (a) were excited only by A.delta. cutaneous afferents and class 3 (b) by both A.delta. and C cutaneous afferents. Some of the latter were also excited by A.delta. and C afferent fibers in the lateral gastrocnemius nerve. When tested by natural stimulation all class 3 cells were excited by noxious mechanical stimuli, but only the 3 (b) units were effectively excited by heating the skin. This discharge in 3 (b) units could be suppressed by electrical stimulation of large (group II) cutaneous myelinated afferent fibers, and a similar effect could be produced in responses evoked by A.delta. and C afferent volleys. Additional inhibition was accomplished by electrical stimulation of the slower mylinated cutaneous (A.DELTA. or group III) afferent fibers. The excitability of the class 3 cells was greater in spinal preparations, but the tonic descending inhibition was weaker than the apparently similar descending tonic inhibition of class 2 cells. The results were discussed with reference to pain mechanisms.