Spinal laminae I-II neurons in rat recorded in vivo in whole cell, tight seal configuration: Properties and opioid responses
Spinal laminae I-II neurons in rat recorded in vivo in whole cell, tight seal configuration: Properties and opioid responses
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DOI：
10.1152/jn.1999.82.6.3316
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发表时间：
1999-12-01
影响因子：
2.5
通讯作者：
Willcockson, HH
中科院分区：
文献类型：
--
作者：
Light, AR;Willcockson, HH
使用在体内的全细胞记录程序之前描述的，我们记录了73个神经元在板层I和II：在大鼠的腰髓。输入阻抗平均为332 M Ω，这表明先前的尖锐电极记录包含显著的分流。充分的刺激，从兴奋性后肢接受举行的表征表明，39的73个神经元是伤害性的，6个是无害的冷却细胞，20个最大的反应刷，和8个细胞不兴奋的皮肤刺激的后肢。15个神经元的位置用生物胞素标记。伤害性感受神经元主要分布在I层和外II层，冷却细胞主要分布在I层，而无害的机械感受细胞主要分布在内II层或上覆的白色物质中。μ阿片激动剂[D-Ala（2），N-Me-Phe（4），Gly（5）-ol]-Enkephalin（DAMGO）使19个被测神经元中的7个超极化，电导增加。这种超极化在应用纳洛酮的神经元中被逆转。DAMGO还降低了13个神经元的自发PSP频率，其中7个神经元也被DAMGO超极化。七个超极化神经元中有五个是伤害性的，对热和机械伤害性刺激都有反应，而两个对缓慢、无害的刷子有反应。这些结果表明，全细胞，紧密密封的记录样品的一个类似的人口的板层I和II神经元在大鼠与猫和猴的尖锐电极记录发现。他们进一步表明，DAMGO超极化具有来自热和机械伤害感受器的输入的伤害感受神经元的子集，并且可以在未被DAMGO超极化的伤害感受神经元中观察到突触前DAMGO效应。
Using the in vivo whole cell recording procedure described previously, we recorded 73 neurons in laminae I and II: in the lumbar spinal cord of the rat. Input impedances averaged 332 M Omega, which indicated that prior sharp electrode recordings contained a significant current shunt. Characterization of the adequate stimuli from the excitatory hindlimb receptive held indicated that 39 of 73 neurons were nociceptive, 6 were innocuous cooling cells, 20 responded maximally to brush, and 8 cells were not excited by stimulation of the skin of the hindlimb. The locations of 15 neurons were marked with biocytin. Nociceptive neurons were mostly found in lamina I and outer II, cooling cells in lamina I, and innocuous mechanoreceptive cells were mostly found in inner II or in the overlying white matter. The mu-opioid agonist [D-Ala(2), N-Me-Phe(4), Gly(5)-ol]-Enkephalin (DAMGO) hyperpolarized 7 of 19 tested neurons with a conductance increase. This hyperpolarization was reversed by naloxone in the neurons in which it was applied. DAMGO also decreased the frequency of spontaneous PSPs in 13 neurons, 7 of which were also hyperpolarized by DAMGO. Five of the seven hyperpolarized neurons were nociceptive, responding to both heat and mechanically noxious stimuli, whereas two responded to slow, innocuous brush. These results indicate that whole cell, tight seal recordings sample a similar population of lamina I and II neurons in the rat as those found with sharp electrode recordings in cat and monkey. They further indicate that DAMGO hyperpolarizes a subset of the nociceptive neurons that have input from both heat and mechanical nociceptors and that presynaptic DAMGO effects can be observed in nociceptive neurons that are not hyperpolarized by DAMGO.