Descending facilitatory modulation of a behavioral nociceptive response by stimulation in the adult rat anterior cingulate cortex
Descending facilitatory modulation of a behavioral nociceptive response by stimulation in the adult rat anterior cingulate cortex
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DOI：
10.1053/eujp.1999.0158
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发表时间：
2000-01-01
影响因子：
3.6
通讯作者：
Zhuo, M
中科院分区：
文献类型：
--
作者：
Calejesan, AA;Kim, SJ;Zhuo, M
研究表明，包括中脑导水管周围灰质（PAG）和延髓头端腹侧区（RVM）在内的下行内源性镇痛系统在痛觉传递和吗啡、大麻素镇痛的调节中起重要作用。PAG中的神经元接收来自高级结构的不同核团的输入，包括前扣带皮层（ACC）。然而，目前尚不清楚是否刺激ACC中的神经元调节脊髓伤害性传递。本研究探讨了电刺激和化学激活的代谢型谷氨酸受体（mGluRs）在ACC的脊髓伤害性甩尾（TF）反射引起的伤害性加热的影响。在高强度（高达500 μ A）的电刺激下激活ACC不产生任何抗伤害感受效应。相反，在ACC内的大多数部位（n = 41个部位中的36个），电刺激对TF反射产生显著的促进作用（即TF潜伏期减少）。ACC内mGluRs的化学激活也产生了促进作用。ACC的下行易化作用在RVM上有明显的中继作用。RVM中的电刺激产生双相调节效应，在低强度下显示促进作用，在较高强度下显示抑制作用。本研究提供的证据表明，激活前扣带内的mGluRs可以促进脊髓伤害性感受。(C)2000年国际疼痛研究协会欧洲分会联合会。
It is well documented that the descending endogenous analgesia system, including the periaqueductal gray (PAG) and the rostral ventral medulla (RVM), play an important role in modulation of nociceptive transmission and morphine- and cannabinoid-produced analgesia. Neurons in the PAG receive inputs from different nuclei of higher structures, including the anterior cingulate cortex (ACC). However, it is unclear if stimulation of neurons in the ACC modulates spinal nociceptive transmission. The present study has examined the effects of electrical stimulation and chemical activation of metabotropic glutamate receptors (mGluRs) in the ACC on a spinal nociceptive tail-flick (TF) reflex induced by noxious heating. Activation of the ACC at high intensities (up to 500 mu A) of electrical stimulation did not produce any antinociceptive effect. Instead, at most sites within the ACC (n = 36 of 41 sites), electrical stimulation produced significant facilitation of the TF reflex (i.e. decreases in TF latency). Chemical activation of mGluRs within the ACC also produced a facilitatory effect. Descending facilitation from the ACC apparently relays at the RVM. Electrical stimulation in the RVM produces a biphasic modulatory effect, showing facilitation at low intensities and inhibition at higher intensities. The present study provides evidence that activation of mGluRs within the ACC can facilitate spinal nociception. (C) 2000 European Federation of Chapters of the International Association for the Study of Pain.