Department of Pharmacology and Toxicology, School of Medical Sciences, University of Otago Medical School, P.O. Box 913, Dunedin, New Zealand.
Neuroscience. 2011 Apr 28;180:75-84. doi: 10.1016/j.neuroscience.2011.02.040. Epub 2011 Feb 23.
Although tinnitus is an auditory disorder, it is often associated with attentional and emotional problems. Functional neuroimaging studies in humans have revealed that the hippocampus, amygdala and anterior cingulate, areas of the brain involved in emotion, attention and spatial processing, are also involved in auditory memory and tinnitus perception. However, few studies of tinnitus-evoked emotional and cognitive changes have been reported using animal models of tinnitus. In the present study, we investigated whether acoustic trauma that could cause tinnitus would affect attention and impulsivity in rats. Eight male Wistar rats were exposed to unilateral acoustic trauma (110 dB, 16 kHz for 1 h under anaesthesia) and eight rats underwent the same anaesthesia without acoustic trauma. Tinnitus was tested in noise-exposed rats using a frequency-specific shift in a discrimination function with a conditioned lick suppression paradigm. At 4 months after the noise exposure, the rats were tested in a 5-choice serial reaction time task. The behavioural procedure involved training the rats to discriminate a brief visual stimulus presented randomly in one of the five spatial locations and responding by poking its nose through the illuminated hole and collecting a food pellet from the magazine. While all of the animals performed equally well in making correct responses, the animals exposed to acoustic trauma made significantly more premature responses. The results suggest that rats exposed to acoustic trauma and some of which have chronic tinnitus are impaired in impulsive control, but not performance accuracy.
虽然耳鸣是一种听觉障碍，但它常与注意力和情绪问题有关。人类的功能神经影像学研究表明，大脑中涉及情绪、注意力和空间处理的海马体、杏仁核和前扣带也与听觉记忆和耳鸣感知有关。然而，使用耳鸣动物模型的研究很少报道与耳鸣诱发的情绪和认知变化有关。在本研究中，我们研究了听觉创伤（麻醉下暴露于 110dB、16kHz 持续 1 小时）是否会影响大鼠的注意力和冲动性。8 只雄性 Wistar 大鼠接受单侧听觉创伤，8 只大鼠接受相同的麻醉但不接受听觉创伤。在噪声暴露大鼠中，使用条件性舔抑制范式，通过辨别函数的频率特异性移位来测试耳鸣。在噪声暴露后 4 个月，大鼠在 5 个选择的序列反应时间任务中进行测试。行为程序包括训练大鼠随机在五个空间位置之一辨别短暂的视觉刺激，并通过戳穿照亮的孔将鼻子伸进孔中并从杂志中取出食物丸来做出反应。虽然所有动物在做出正确反应方面表现相同，但暴露于听觉创伤的动物做出的过早反应明显更多。结果表明，暴露于听觉创伤且部分患有慢性耳鸣的大鼠在冲动控制方面受损，但在表现准确性方面没有受损。
