ALPHA(2)-ADRENOCEPTOR MEDIATED INHIBITION OF [H-3] DOPAMINE RELEASE FROM NUCLEUS-ACCUMBENS SLICES AND MONOAMINE LEVELS IN A RAT MODEL FOR ATTENTION-DEFICIT HYPERACTIVITY DISORDER
ALPHA(2)-ADRENOCEPTOR MEDIATED INHIBITION OF [H-3] DOPAMINE RELEASE FROM NUCLEUS-ACCUMBENS SLICES AND MONOAMINE LEVELS IN A RAT MODEL FOR ATTENTION-DEFICIT HYPERACTIVITY DISORDER
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DOI：
10.1007/bf00973098
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发表时间：
1995-04-01
影响因子：
4.4
通讯作者：
TALJAARD, JJF
中科院分区：
文献类型：
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作者：
DEVILLIERS, AS;RUSSELL, VA;TALJAARD, JJF
自发性高血压大鼠（SHR）已被提议作为注意缺陷多动障碍（ADHD）的动物模型。行为问题被认为是继发于强化机制的改变，其中丘脑核多巴胺能活性起着重要作用。在自发性高血压大鼠中，去甲肾上腺素能和多巴胺能系统之间的相互作用与自发性高血压大鼠的运动过度活跃和辨别能力受损有关。因此，本研究调查是否有任何变化，在α（2）-肾上腺素受体介导的抑制多巴胺释放从自发性高血压大鼠的脑桥核片与他们的正常血压的Wistar-Kyoto（WKY）控制相比。在SHR和WKY大鼠，α（2）-肾上腺素能受体激动剂UK 14，304可使电刺激下丘脑背侧核脑片[H-3]多巴胺（DA）释放量减少到相似的程度。SHR的蓝斑核和A（2）核的基础去甲肾上腺素（NE）水平升高，而A（2）核的NE水平无明显变化;这些结果表明，主要功能障碍的LC和A（2）核通过α（2）-肾上腺素受体介导的DA释放抑制对延髓核中的多巴胺能传递没有继发性影响。SHR与WKY大鼠不同脑区的基础单胺水平有显著差异。与WKY相比，SHR的DA和5-HT转换率降低，提示SHR某些脑区的多巴胺能和多巴胺能系统功能低下。
The spontaneously hypertensive rat (SHR) has been proposed as an animal model for attention-deficit hyperactivity disorder (ADHD). The behavioural problems have been suggested to be secondary to altered reinforcement mechanisms in which nucleus accumbens dopaminergic activity plays an important role. Interaction between the noradrenergic and dopaminergic system in the nucleus accumbens has been implicated in the locomotor hyperactivity and impaired discriminative performance of SHR. The present study therefore investigated whether there was any change in the alpha(2)-adrenoceptor mediated inhibition of dopamine release from nucleus accumbens slices of SHR in comparison with their normotensive Wistar-Kyoto (WKY) controls. The electrically stimulated release of [H-3]dopamine (DA) from nucleus accumbens slices was decreased to a similar extent by UK14,304, an alpha(2)-adrenoceptor agonist, in SHR and WKY. Basal norepinephrine (NE) levels were increased in locus coeruleus (LC) and A(2) noradrenergic nuclei, but not in the A(2) nucleus of SHR, while basal serotonin (5-HT) levels were increased in all these pons-medulla nuclei. These results suggest that a primarily dysfunctional LC and A(2) nucleus does not have a secondary effect on dopaminergic transmission in the nucleus accumbens via alpha(2)-adrenoceptor mediated inhibition of DA release. Basal monoamine levels in several brain areas of SHR were significantly different from that of WKY. DA, and 5-HT turnover were decreased in SHR versus WKY suggesting hypofunctional dopaminergic and serotonergic systems in some barin areas of SHR.