Department of Life Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
Exp Brain Res. 2011 Nov;215(1):45-52. doi: 10.1007/s00221-011-2869-7. Epub 2011 Sep 20.
The spontaneously hypertensive rat (SHR) is the most commonly used model of attention-deficit hyperactivity disorder (ADHD), displaying the main symptoms of the disorder which are responsive to psychostimulant treatments. Research to date has focused on behavioural tests investigating functioning of the striatum or prefrontal cortex in these rats. However, there is now evidence that the superior colliculus, a structure associated with head and eye movements, may also be dysfunctional in ADHD. Therefore, the aim of this study was to investigate whether the SHR demonstrated impairment in collicular-dependent behaviour. To this end, we examined air righting behaviour, which has previously been shown to be modulated in a height-dependent manner reliant on a functional superior colliculus. We assessed SHR, Wistar Kyotos and Wistars on static righting and air righting at 50 and 10 cm drop heights. There were no differences in static righting, indicating that there were no gross motor differences that would confound air righting. Qualitative analysis of video footage of the righting did not reveal any changes previously associated with collicular damage, unique to the SHR. However, the SHR did show impairment in height-dependent modulation of righting in contrast to both control strains, such that the SHR failed to modulate righting latency according to drop height. This failure is indicative of collicular abnormality. Given that many rodent tests of attentional mechanisms involve head and eye orienting, which are heavily dependent on the colliculus, a collicular dysfunction has strong implications for the type of attentional task used in this strain.
自发性高血压大鼠（SHR）是注意力缺陷多动障碍（ADHD）最常用的模型，表现出该疾病的主要症状，对精神兴奋剂治疗有反应。迄今为止，研究主要集中在行为测试上，这些测试调查了这些大鼠的纹状体或前额叶皮层的功能。然而，现在有证据表明，与头部和眼球运动相关的上丘，在 ADHD 中也可能出现功能障碍。因此，本研究的目的是研究 SHR 是否表现出与上丘相关的行为障碍。为此，我们检查了空中翻转行为，此前的研究表明，这种行为以前依赖于功能正常的上丘，以高度依赖的方式进行调节。我们评估了 SHR、WistarKyotos 和 Wistars 在静态和 50cm 和 10cm 落差的空中翻转。静态翻转没有差异，表明没有混淆空中翻转的严重运动差异。对翻转的视频片段的定性分析没有揭示出任何与上丘损伤相关的以前与 SHR 独特的变化。然而，与两种对照品系相比，SHR 在高度依赖性的翻转调节中确实存在障碍，以至于 SHR 无法根据落差调节翻转潜伏期。这种失败表明上丘异常。鉴于许多涉及头部和眼睛定向的注意力机制的啮齿动物测试，这些都严重依赖于上丘，因此上丘功能障碍对该品系中使用的注意力任务类型有很强的影响。
