抄録
In this study, the effects of acoustic stimuli on the heart rate fluctuations (HRFs) and autonomic nervous system activity in prenatal chick embryos was investigated. Here, instantaneous
heart rate measurements were collected while the embryos were exposed to three types of acoustic
stimuli – classical music, rock music, and hatchling cheeps – for 30 min per day from embryonic
days 16 through 20 prior to hatching day. The results showed that the frequency of the HRFs was higher when rock music was played than when classical music was played. However, the autonomic nervous system activity did not change significantly with rock versus classical music or over the days of incubation. During the perinatal period, the effects of acoustic stimuli on the autonomic nervous system activity did not exceed the effects of physiological and biological development. This may be because the 1/f frequency component of the music is filtered out by the egg. However, the 1/f spectrum of heartbeat rhythm is not affected by the sound-filtering effect of the eggs, so it is possible that the presence of 1/f fluctuations in the maternal heartbeat rhythm affects the autonomic nervous
system activity of the chick embryo. Therefore, further studies are needed to investigate the response of the embryo to the vibrational stimulus of the direct heartbeat.
