Histamine improves rat rota-rod and balance beam performances through H2 receptors in the cerebellar interpositus nucleus
Histamine improves rat rota-rod and balance beam performances through H2 receptors in the cerebellar interpositus nucleus
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DOI：
10.1016/j.neuroscience.2006.01.045
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发表时间：
2006-01-01
期刊：
影响因子：
3.3
通讯作者：
Wang, J. -J.
中科院分区：
文献类型：
--
作者：
Song, Y. -N.;Li, H. -Z.;Wang, J. -J.
以往的研究表明，组胺能从下丘脑结节乳头核直接投射到小脑，并通过组胺H-2受体对小脑间位核神经元产生突触后兴奋作用，提示小脑核团的组胺能传入输入可能参与了小脑的运动控制功能。为了验证这一假设，在这项研究中，组胺能药物被微量注射到完整的成年雄性大鼠的小脑间位核，并观察其对运动的平衡和协调的动物执行加速旋转杆跑步机和平衡木任务的影响。结果表明，小脑间位核微量注射组胺可显著延长动物在旋转杆上的稳定平衡时间，缩短动物通过平衡木的时间，而GABA则显著抑制动物在旋转杆和平衡木上的运动成绩，生理盐水对两者均无影响。此外，选择性组胺H-2受体拮抗剂雷尼替丁可明显缩短动物的转棒耐力时间，增加小鼠的横梁通过时间，而选择性组胺H-1受体拮抗剂曲普利啶则无此作用。此外，微量注射组胺逆转雷尼替丁对旋转杆和横梁性能的抑制作用。这些结果表明，组胺增强大鼠运动的平衡和协调，通过激活组胺H-2受体在小脑间位核，并建议下丘脑小脑组胺能投射可能发挥调节作用，对小脑电路，以确保运动准确执行。(c)2006由Elsevier Ltd代表IBRO出版。
Previous studies have revealed a direct histaminergic projection from the tuberomamillary nucleus of hypothalamus to the cerebellum and a postsynaptic excitatory effect of histamine on the cerebellar interpositus nucleus neurons via histamine H-2 receptors in vitro, indicating that the histaminergic afferent inputs of cerebellar nuclei may be involved in the cerebellar function of motor control. To test this hypothesis, in this study histaminergic agents were bilaterally microinjected into the cerebellar interpositus nucleus of intact adult male rats, and their effects on motor balance and coordination of the animals performing accelerating rota-rod treadmill and balance beam tasks were observed. The results showed that microinjection of histamine into the cerebellar interpositus nucleus remarkably increased the time that animals balanced steadily on the rota-rod and markedly shortened the duration of passage through the balance beam, whereas GABA significantly depressed motor performances of animals on the rota-rod and beam, and normal saline influenced neither. In addition, administration of selective histamine H-2 receptor antagonist ranitidine considerably decreased the animals' endurance time on rota-rod and noticeably increased the passing time on beam, but selective histamine H-1 receptor antagonist triprolidine showed no effect. Furthermore, microinjection of histamine reversed the inhibitory effects of ranitidine on rota-rod and beam performance. These results demonstrate that histamine enhances rat motor balance and coordination through activation of histamine H-2 receptors in the cerebellar interpositus nucleus and suggest that the hypothalamocerebellar histaminergic projections may play a modulatory role on the cerebellar circuitry to ensure that movements are accurately executed. (c) 2006 Published by Elsevier Ltd on behalf of IBRO.