We studied aggression in male Sprague-Dawley rats in a model of a depressive-like state induced by unpredictable treatment with ultrasonic waves with the frequencies of 20-45 kHz for 1, 2 or 3 weeks. We did not find any increase in the number of animals exhibiting aggression in the "resident-intruder" test after the treatment of any selected duration. However, the aggressive animals exposed to ultrasound exhibited the substantially increased number of attacks and their total duration as well as decreased latency of the first attack compared to the respective indices in the animals of the control group. Taking this into account, it is possible to suggest that the initial level of aggression increases in a model of ultrasonic chronic stress.

中文翻译：

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慢性暴露于超声频率选择性地增加了大鼠的攻击性。

我们研究了雄性Sprague-Dawley大鼠的攻击性，该模型是通过对频率为20-45 kHz的超声波进行不可预测的治疗1、2或3周而诱发的抑郁样状态。在选择任何持续时间的治疗后，在“常驻入侵者”测试中我们没有发现表现出攻击性的动物数量有任何增加。然而，与对照组动物的各个指标相比，暴露于超声的攻击性动物表现出攻击次数及其总持续时间显着增加，并且首次攻击的潜伏期缩短。考虑到这一点，有可能表明，在超声慢性应激模型中，初始攻击水平会增加。