Distribution of serotonin 2A and 2C receptor mRNA expression in the cervical ventral horn and phrenic motoneurons following spinal cord hemisection
Distribution of serotonin 2A and 2C receptor mRNA expression in the cervical ventral horn and phrenic motoneurons following spinal cord hemisection
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DOI：
10.1006/exnr.2001.7682
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发表时间：
2001-06-01
影响因子：
5.3
通讯作者：
Goshgarian, HG
中科院分区：
文献类型：
--
作者：
Basura, GJ;Zhou, SY;Goshgarian, HG
颈髓损伤导致延髓呼吸中枢至膈运动神经元的球脊髓神经支配中断，利用颈部半切的动物模型导致同侧膈神经活动抑制，导致半侧膈麻痹。我们之前已经证明了血清素（5-HT）作为颈部半切后呼吸恢复的一种潜在调节剂的作用，这一机制可能通过5-HT 2A和/或5-HT 2C受体发生。本研究旨在专门检查5-HT 2A和/或5-HT 2C受体是否与完整和脊髓半切大鼠的膈运动神经元共定位。成年雌性大鼠（250-350 g;每组n = 6）接受左颈（C2）半切，并将荧光逆行神经元示踪剂Fluorogold注射到左半膈中。24小时后，处死动物，脊髓进行原位杂交和免疫组织化学处理。使用S-35标记的cRNA探针，探测颈脊髓5-HT 2A和5-HT 2C受体mRNA的表达，并使用荧光金抗体进行双标记，以检测膈运动神经元。5-HT 2A和5-HT 2C受体mRNA在颈前角运动神经元中均有表达。尽管5-HT 2A和5-HT 2C受体mRNA杂交信号在膈运动神经元上均呈阳性表达，但只有5-HT 2A银颗粒达到了代表共定位的信噪比。与假手术对照组相比，颈半切后膈运动神经元中5-HT 2A mRNA水平没有显著改变。5-HT 2A受体mRNA与膈运动神经元的选择性共定位可能对最近观察到的5-HT 2A受体介导的呼吸活动调节和/或完整和损伤受损状态下的恢复具有影响。(C)北京：科学出版社.
Cervical spinal cord injury leads to a disruption of bulbospinal innervation from medullary respiratory centers to phrenic motoneurons, Animal models utilizing cervical hemisection result in inhibition of ipsilateral phrenic nerve activity, leading to paralysis of the hemidiaphragm. We have previously demonstrated a role for serotonin (5-HT) as one potential modulator of respiratory recovery following cervical hemisection, a mechanism that likely occurs via 5-HT2A and/or 5-HT2C receptors, The present study was designed to specifically examine if 5-HT2A and/or 5-HT2C receptors are colocalized with phrenic motoneurons in both intact and spinal-hemisected rats. Adult female rats (250-350 g; n = 6 per group) received a left cervical (C2) hemisection and were injected with the fluorescent retrograde neuronal tracer Fluorogold into the left hemidiaphragm. Twenty-four hours later, animals were killed and spinal cords processed for in situ hybridization and immunohistochemistry. Using S-35-labeled cRNA probes, cervical spinal cords were probed for 5-HT2A and 5-HT2C receptor mRNA expression and double-labeled using an antibody to Fluorogold to detect phrenic motoneurons. Expression of both 5-HT2A and 5-HT2C receptor mRNA was detected in motoneurons of the cervical ventral horn. Despite positive expression of both 5-HT2A and 5-HT2C receptor mRNA-hybridization signal over phrenic motoneurons, only 5-HT2A silver grains achieved a signal-to-noise ratio representative of colocalization. 5-HT2A mRNA levels in identified phrenic motoneurons were not significantly altered following cervical hemisection compared to sham-operated controls, Selective colocalization of 5-HT2A receptor mRNA with phrenic motoneurons may have implications for recently observed 5-HT2A receptor-mediated regulation of respiratory activity and/or recovery in both intact and injury-compromised states. (C) 2001 Academic Press.