ヤギおよびラットにおける短期的な音響曝露ストレスの評価

抄録

Low frequency noise has been recognized as an environmental noise problem. It has been reported that low frequency noise would adversely affect human mental performance and interfere with the normal immune response to infection. The purpose of this study was to evaluate the frequency that served as a stressor to Shiba goats and the response to sound in different species. Shiba goats and Donryu rats were used for the experiment. Sound waves from 50 to 4000 Hz were generated for 1 minute at increments of 10 Hz at 50, 70, and 90 dB, respectively. Also, sound waves from 4000 to 50 Hz were generated at decrements of 10 Hz at 50, 70, and 90 dB, respectively. While animals were exposed to these sounds, we observed their responses and counted the number of such reactions. The concentration of cortisol in saliva, heart rate and brain oxyecoia saturation of the goats were measured. In the goats, marked stress behavior was observed in the frequency band of 100-500 Hz. The presence of stress was supported by the results of measurement of cortisol concentration, heart rate and brain oxyecoia saturation. On the other hand, in the rats, no frequency band was identified that produced a remarkable response. The frequency band of 100-500 Hz seems to serve as a stressor to the goats.