Choe Yunhwan, Park Ilyong
Department of Biomedical Engineering, College of Medicine, Dankook University, Cheonan, Korea.
Biomed Eng Lett. 2019 May 10;9(3):367-374. doi: 10.1007/s13534-019-00109-9. eCollection 2019 Aug.
Gap prepulse inhibition of acoustic startle (GPIAS) method has been used effectively for the objective assessment of tinnitus in animals. Among two types of enclosures for the GPIAS, the unconstrained type carries less risk of animal death due to the absence of binding stress in the enclosure, and lack of need for alteration to animal size variation as it grows. However, animals' voluntary movements, which have no relation to the startles evoked by acoustic stimuli, are problematic, as they cannot be excluded in the case of the unconstrained enclosure based GPIAS measurement system. In order to discount voluntary movements which are not associated with external acoustic stimuli, we propose the conditional random inter-stimulus interval (CR ISI) method for unconstrained enclosure based GPIAS measurement. With the proposed ISI method, the unconstrained enclosure based acoustic startle response measurement system has been implemented in this paper. As a result, the effectiveness of the proposed CR ISI method has been verified and compared with those of conventional ISI methods through animal experiments using SD-rats. The experimental results showed that abnormal startle responses and invalid GPIAS values caused by motion were prevented when our proposed CR ISI method was applied to our implemented system. It was also verified that our proposed CR ISI method is advantageous in reducing the total experimental time for acquiring normal startle responses and valid GPIAS values, compared to conventional ISI methods, since our proposed CR ISI can begin the acoustic stimulation only when the animal gets stable and motionless.
听觉惊吓的间隙前脉冲抑制（GPIAS）方法已被有效地用于动物耳鸣的客观评估。在用于GPIAS的两种类型的饲养箱中，无约束型由于饲养箱中不存在束缚应激，并且随着动物生长无需因动物体型变化而进行调整，因此动物死亡风险较小。然而，与听觉刺激诱发的惊吓无关的动物自主运动存在问题，因为在基于无约束饲养箱的GPIAS测量系统中无法排除这种运动。为了排除与外部听觉刺激无关的自主运动，我们提出了用于基于无约束饲养箱的GPIAS测量的条件随机刺激间隔（CR ISI）方法。本文采用所提出的ISI方法，实现了基于无约束饲养箱的听觉惊吓反应测量系统。结果，通过使用SD大鼠的动物实验，验证了所提出的CR ISI方法的有效性，并与传统ISI方法进行了比较。实验结果表明，将我们提出的CR ISI方法应用于我们实现的系统时，可以防止由运动引起的异常惊吓反应和无效的GPIAS值。还证实，与传统ISI方法相比，我们提出的CR ISI方法在减少获取正常惊吓反应和有效GPIAS值的总实验时间方面具有优势，因为我们提出的CR ISI仅在动物稳定不动时才开始听觉刺激。
