Effect of prenatal chronic noise exposure on the growth and development of body and brain of chick embryo

CONTEXT: Noise acts as an environmental stressor as has been demonstrated by an increased brain acetyl cholinesterase activity as well as elevated plasma corticosterone and adrenocorticotropic hormone levels. Noise can lead to neurodegenerative changes in the brain and in the ear. AIM: This study was undertaken to investigate the effect of chronic noise on growth and development during the sensitive period of embryonic life. MATERIALS AND METHODS: In this study, we analyzed the body weight, brain weight and brain size following prenatal chronic noise exposure. Fertilized eggs of domestic chicks were exposed to chronic excessive acoustic stimulation with frequency of the sound ranging from 30 to 3000 Hz with a peak at 2700 Hz was given at 110 dB sound pressure level from embryonic day (E) 10 until hatching. RESULTS: An appreciable decrease in body weight, brain weight and brain size was evident in the experimental group exposed to noise. A generalized decrease in the neuronal nuclear size and increase in the density of neurons was also observed. CONCLUSION: These observations could be an indicator of growth and developmental retardation following exposure to noise.