Excitatory effects of histamine on cerebellar interpositus nuclear cells of rats through H2 receptors in vitro
Excitatory effects of histamine on cerebellar interpositus nuclear cells of rats through H2 receptors in vitro
复制标题
组胺通过H2受体对大鼠小脑间核细胞的体外兴奋作用
DOI：
10.1016/s0006-8993(02)02950-5
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发表时间：
2002-09-06
期刊：
影响因子：
2.9
通讯作者：
Wang, JJ
中科院分区：
文献类型：
--
作者：
Shen, B;Li, HZ;Wang, JJ
神经解剖学研究揭示了一个直接的下丘脑小脑组胺能通路，我们以前的研究已经证明了兴奋作用的组胺颗粒和浦肯野细胞的小脑皮质。本研究利用小脑脑片进一步研究了组胺对小脑间位核神经元放电的影响。从38个切片中记录了87个IN细胞。绝大多数细胞对组胺刺激无反应（79/87，90.8%），其余细胞无反应（8/87，9.2%）。应用低Ca ~（2+）/高Mg ~（2+）培养基（n = 8）不能阻断组胺引起的兴奋，支持组胺的直接突触后作用。组胺H-2受体拮抗剂雷尼替丁能有效地阻断组胺对IN细胞的兴奋性反应（n = 23），而组胺H-1受体拮抗剂曲普利啶不能显著阻断组胺对IN细胞的兴奋性反应，或仅轻微地降低组胺对IN细胞的兴奋性反应（n = 21）。另一方面，高选择性组胺H-2受体激动剂二甲双胍模拟组胺对IN细胞的兴奋作用，并且二甲双胍诱导的兴奋也被雷尼替丁阻断（n = 14）。用雷尼替丁和曲普利啶分别灌流脑片，发现雷尼替丁对dimapritt诱发的兴奋有同样的阻断作用，而曲普利啶则无此作用（n = 8）。此外，组胺H1受体激动剂2-吡啶基乙胺对IN细胞没有显示任何作用（n = 9）。这些结果表明，组胺兴奋小脑IN细胞通过组胺H-2受体机制。结合我们以前的研究结果，我们认为下丘脑小脑组胺能纤维可能平行地调节小脑皮质和深部核团的神经元活动。本文还讨论了组胺对小脑核细胞兴奋作用的意义。(C)2002 Elsevier Science B. V.保留所有权利。
Neuroanatomical studies have revealed a direct hypothalamocerebellar histaminergic pathway, and our previous studies have demonstrated an excitatory effect of histamine on granule and Purkinje cells of the cerebellar cortex. In this study, we further investigated the effect of histamine on the neuronal firing of cerebellar interpositus nucleus (IN) by using cerebellar slice preparations. Eighty-seven IN cells were recorded from 38 slices. The vast majority of the cells responded to histamine stimulation with in excitatory response (79/87, 90.8%), and the rest of them showed no reaction (8/87, 9.2%). The histamine-induced excitation was not blocked by application Of low-Ca2+ /high-Mg2+ medium (n = 8), supporting a direct postsynaptic action of histamine. The histamine H-2 receptor antagonist ranitidine effectively blocked the excitatory response of IN cells to histamine (n = 23), but the histamine H-1 receptor antagonist triprolidine could not significantly block the histamine-induced excitation, or only very slightly decreased the excitatory effect of histamine on the cells (n = 21). On the other hand, the highly selective histamine H-2 receptor agonist dimaprit mimicked the excitatory effect of histamine on IN cells and the dimaprit-induced excitation was also blocked by ranitidine (n = 14). Successively perfusing slices with the medium containing ranitidine and triprolidine, respectively, we found that ranitidine exhibited the same blocking effect on the dimaprit-induced excitation, but triprolidine had no such effect (n = 8). Moreover, the histamine H, receptor agonist 2-pyridylethylamine did not show any effect on the IN cells (n = 9). These results demonstrate that histamine excites cerebellar IN cells via the histamine H-2 receptor mechanism. Together with our previous results, we suggest that the hypothalumocerebellar histaminergic fibers may modulate neuronal activities of the cerebellar cortex and deep nuclei in parallel. The significance of the excitatory effect of histamine on the cerebellar nuclear cells is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.