| Budget Amount *help |
¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
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| Outline of Final Research Achievements |
Methods: Pregnant wild-type C57BL/6 mice with 14, 16, and 18 day embryos (E14, E16, and E18) or mice at postnatal day 1, 3, and 5 (P1, P3, and P5) were used. Acoustic overexposure of an octave of band noise (8 - 16 kHz) at 95, 100, 105, 110, and 116 dB SPL was applied for 2h. Results: The auditory brainstem response (ABR) of 8, 12, and 16 kHz in the E16 group were significantly increased compared to the control group (p < 0.05). The hearing loss of E16 C57BL/6 mice was sound pressure dependent at 8 kHz and 12 kHz. Noise exposure to E16 C57BL/6 mice did not alter the inner ear hair cells (HCs) or spiral ganglion (SG) cells. Conclusion: Noise exposure during the embryonic stage and in neonatal mice affected cochlear function that was evident at postnatal day 28. Further studies are needed to determine the precise mechanism underlying the acoustic effect in embryos and neonatal mice.
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