Nociceptin inhibits calcium channel currents in a subpopulation of small nociceptive trigeminal ganglion neurons in mouse
Nociceptin inhibits calcium channel currents in a subpopulation of small nociceptive trigeminal ganglion neurons in mouse
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DOI：
10.1111/j.1469-7793.2001.t01-1-00035.x
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发表时间：
2001-10-01
影响因子：
5.5
通讯作者：
Christie, MJ
中科院分区：
文献类型：
--
作者：
Borgland, SL;Connor, M;Christie, MJ
1.在急性分离的小鼠三叉神经节神经元上，采用全细胞膜片钳技术观察了孤啡肽（N/OFQ）和阿片受体激动剂对电压激活钙通道电流（I-Ca）的影响。这些效应与辣椒素引起的神经元反应和与Bandeiraea simplicifolia isolectin B4（IB 4）结合有关.根据存在（2型）或不存在（1型）突出的T型I-Ca，将三叉神经元分为两个群体。N/OFQ在大多数（82%）小（电容< 12 pF）1型神经元中有效（EC 50为19 nm）抑制高压激活（HVA）I-Ca，但在少数（9%）大（< 12 pF）1型神经元中有效（EC 50为19 nm）抑制高压激活（HVA）I-Ca。N/OFQ抑制少数（23%）2型细胞的I-Ca，而不影响任何细胞的T型I-Ca.μ-阿片激动剂DAMGO和吗啡在大多数1型神经元中抑制I-Ca，在小细胞中更常见（95%对77%）。DAMGO和吗啡对I-Ca的抑制在小的I型神经元中比在大的I型神经元中更有效。μ-阿片类药物不抑制2型神经元的I-Ca。大多数小的1型神经元对辣椒素（93%）和结合的IB 4（86%）敏感。较少较大的I型神经元对辣椒素（30%）或结合的IB 4（58%）有反应。2型神经元对辣椒素没有反应，尽管一些结合了IB 4（35%）。因此，N/OFQ优先抑制小伤害感受性三叉神经节神经元亚群中的HVA I-Ca，其也是高度敏感的μ阿片激动剂。
1. The effects of nociceptin/orphanin FQ (N/OFQ) and opioid receptor agonists on voltage-activated calcium channel currents (I-Ca) were examined in acutely isolated mouse trigeminal ganglion neurons using whole-cell patch-clamp recordings. These effects were correlated with responses of the neurons to capsaicin and binding of Bandeiraea simplicifolia isolectin B4 (IB4).2. Trigeminal neurons were divided into two populations based on the presence (type 2) or absence (type 1) of a prominent T-type I-Ca N/OFQ potently (EC50 of 19 nm) inhibited high-voltage-activated (HVA) I-Ca in most (82%) small (capacitance < 12 pF) type 1 neurons, but few (9%) larger (< 12 pF) type 1 neurons. N/OFQ inhibited I-Ca in few (23%) type 2 cells, and did not affect the T-type I-Ca in any cell.3. The mu -opioid agonists DAMGO and morphine inhibited I-Ca in most type 1 neurons, more often (95% versus 77%) in the small cells. The inhibition of I-Ca by DAMGO and morphine was more efficacious in small versus large type I neurons. mu -Opioids did not inhibit I-Ca in type 2 neurons.4. Most, small type 1 neurons were sensitive to capsaicin (93%) and bound IB4 (86%). Fewer larger type I neurons responded to capsaicin (30%) or bound IB4 (58%). Type 2 neurons did not respond to capsaicin, although some bound IB4 (35%).5. Thus, N/OFQ preferentially inhibits HVA I-Ca in a subpopulation of small nociceptive trigeminal ganglion neurons that is also highly sensitive mu -opioid agonist.