DOPAMINERGIC ACTIVATION EXCITES RAT LATERAL HABENULAR NEURONS IN VIVO
DOPAMINERGIC ACTIVATION EXCITES RAT LATERAL HABENULAR NEURONS IN VIVO
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DOI：
10.1016/j.neuroscience.2009.04.026
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发表时间：
2009-07-21
期刊：
影响因子：
3.3
通讯作者：
Weiss, T.
中科院分区：
文献类型：
--
作者：
Kowski, A. B.;Veh, R. W.;Weiss, T.
上丘脑外侧缰复合体（LHb）是连接基底前脑和中脑调节核团的间脑背侧传导系统的一部分。LHb参与了上行单胺能传递的调节，特别是中脑多巴胺能神经元的活动。在这里，我们已经调查了LHb是否反过来受到多巴胺能调制。在麻醉大鼠中，使用细胞外单单位记录检查了全身应用多巴胺能药物后LHb内自发神经元活动的变化。阿扑吗啡（2毫克/公斤）的管理导致个别LHb神经元的兴奋。平均而言，LHb神经元的自发动作电位放电增加了39%。然而，阿扑吗啡的影响表现出显着的地形差异内的LHb。特别是，一个小的子集的LHb，这是本地化的椭圆形亚核内的外侧分裂的神经元，表现出阿扑吗啡介导的放电频率增加了96%。与此相反，自发放电的神经元在其他领域的外侧分裂没有修改。同样地，在LHb的内侧部内，优先接收来自多巴胺能中脑核的投射的区域，大多数神经元未能显示阿扑吗啡介导的动作电位放电的改变。然而，在该分区的上级亚核内，一个传入供应尚不清楚的区域，自发神经元放电增强了56%。阿扑吗啡介导的兴奋LHb神经元拮抗共同应用氟哌啶醇（2毫克/公斤），单独不改变自发动作电位放电的个别LHb神经元。本研究表明，自发活动的不同子集的神经元内的LHb强烈增强多巴胺能受体的系统激活。尽管样本量小，数据表明，这种多巴胺能调制表现出地形特异性。因此，结果支持大鼠缰复合体的功能亚核组织的假设。(C)2009年IBRO。由爱思唯尔有限公司出版。保留所有权利。
The lateral habenular complex (LHb) of the epithalamus is part of a dorsal diencephalic conduction system connecting basal forebrain with regulatory midbrain nuclei. The LHb has been implicated in the regulation of ascending monoaminergic transmission, particularly midbrain dopaminergic neuronal activity. Here, we have investigated whether the LHb in turn is subject to dopaminergic modulation. Alterations in spontaneous neuronal activity within the LHb following systemic application of dopaminergic drugs have been examined in anesthetized rats using extracellular single unit recordings. The administration of apomorphine (2 mg/kg) resulted in an excitation of individual LHb neurons. On average, the spontaneous action potential firing of the LHb neurons was increased by 39%. However, the apomorphine effect showed marked topographic differences within the LHb. Particularly, a small subset of neurons in the lateral division of the LHb, which was localized within the oval subnucleus, showed an apomorphine-mediated increase in discharge frequency by 96%. In contrast, spontaneous discharge of neurons within other areas of the lateral division was not modified. Likewise, within the medial division of the LHb, a region that preferentially receives projections from dopaminergic midbrain nuclei, the majority of neurons failed to show apomorphine-mediated alterations in action potential firing. However, within the superior subnucleus of this division, an area with yet unclear afferent supply, spontaneous neuronal firing was enhanced by 56%. The apomorphine-mediated excitation of LHb neurons was antagonized by co-application of haloperidol (2 mg/kg), which alone did not alter spontaneous action potential firing of individual LHb neurons. The present study demonstrates that spontaneous activity of distinct subsets of neurons within the LHb is strongly enhanced by systemic activation of dopaminergic receptors. Despite the small sample size, the data suggest that this dopaminergic modulation shows a topographic specificity. Therefore, the results support the hypothesis of a functional subnuclear organization of the rat habenular complex. (C) 2009 IBRO. Published by Elsevier Ltd. All rights reserved.