Histamine promotes rat motor performances by activation of H2 receptors in the cerebellar fastigial nucleus
Histamine promotes rat motor performances by activation of H2 receptors in the cerebellar fastigial nucleus
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DOI：
10.1016/j.bbr.2011.11.029
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发表时间：
2012-03-01
影响因子：
2.7
通讯作者：
Wang, Jian-Jun
中科院分区：
文献类型：
--
作者：
He, Ye-Cheng;Wu, Guan-Yi;Wang, Jian-Jun
小脑顶状核（FN）与间位核（IN）共同构成脊髓小脑的两个最终输出核，在身体和肢体运动中起重要作用。以前的研究已经揭示了从下丘脑到小脑核的直接组胺能投射和组胺对IN神经元的兴奋作用。然而，下丘脑组胺能投射在FN中的作用仍知之甚少。本研究表明，组胺在体外诱导大鼠FN神经元产生浓度依赖性的兴奋反应。组胺诱导的FN神经元兴奋是由突触后组胺H-2介导的，而不是HI受体。行为学实验中，双侧FNs显微注射组胺可显著改善大鼠在加速转杆和平衡木上的运动表现。选择性H-2受体拮抗剂雷尼替丁明显降低运动性能，选择性H-2受体激动剂地马普利模仿组胺对运动的促进作用。但选择性H-1受体拮抗剂triprolidine和激动剂2- pyridy乙胺没有作用。此外，双侧FNs中微量注射组胺可使足迹步幅变窄，但不影响丝悬浮，而双侧INs中微量注射组胺可使步幅变长，促进丝悬浮。这些结果表明，组胺通过激活小脑FN和in中的组胺H2受体来调节近端和远端肌肉，从而增强大鼠运动平衡和协调，并提示下丘脑-小脑组胺能投射可能调节脊髓小脑的最终输出并参与小脑介导的运动控制。(C) 2011 Elsevier B.V.版权所有
The cerebellar fastigial nucleus (FN), together with the interpositus nucleus (IN), constitutes the two final output nuclei of the spinocerebellum and plays an important role in body and limb movements. Previous studies have revealed a direct histaminergic projection from the hypothalamus to the cerebellar nuclei and an excitatory effect of histamine on the IN neurons. However, role of hypothalamic histaminergic projection in the FN has been still little known. Here we show that histamine elicited the FN neurons of rats a concentration-dependent excitatory response in vitro. The histamine-induced excitation on FN neurons was mediated by postsynaptic histamine H-2 rather than HI receptors. In behavioral tests, microinjection of histamine into bilateral FNs remarkably improved motor performances of rats on both accelerating rota-rod and balance beam. Selective H-2 receptor antagonist ranitidine considerably declined those motor performances and selective H-2 receptor agonist dimaprit mimicked the facilitation effect of histamine on the movements. But selective H-1 receptor antagonist triprolidine and agonist 2-pyridylethylamine had no effect. Furthermore, microinjection of histamine into bilateral FNs narrowed stride width of footprint but did not influence wire suspension, whereas microinjection of histamine into bilateral INs increased stride length and promoted suspension. These results demonstrate that histamine enhances rat motor balance and coordination through modulation of both proximal and distal muscles by activation of histamine H2 receptors in the cerebellar FN and IN, and suggest that the hypothalamocerebellar histaminergic projections may modulate the final outputs of the spinocerebellum and participate in the cerebellum-mediated motor control. (C) 2011 Elsevier B.V. All rights reserved.