This study analysed the acoustic and vestibular functional and morphological modifi cations in guinea pigs after acoustic trauma. Animals were exposed to noise (6 kHz, at 120 dB SPL for 60 minutes) and then auditory brainstem responses (ABR) and vestibulo-ocular refl ex (VOR) were measured at 6 hours, 1 day, 3, 7, and 21 days after noise. Western blotting and immunostaining for 4-hydroxy-2-noneal (4-HNE) and vascular endothelial growth factor (VEGF) were performed in the cochlear and vestibular regions at 1 and 7 days after noise exposure. A signifi cant decrease of VOR gain was observed on day 1 and the recovery was completed at day 21. ABR threshold values reached a level of 80 dB at day 1 after trauma reaching a value of about 50 dB SPL on day 21. 4-HNE expression, a marker of lipid peroxidation was strongly increased in the cochlea. In the vestibule, 4-HNE immunoreactivity was faint. However, VEGF was upregulated both in the cochlea and vestibule. In conclusion, the expression of VEGF in both cochlear and vestibular structures suggests a reparative role with potentially therapeutic implications.
Noise induced hearing loss and vestibular dysfunction in the guinea pig
FERRARESI, Aldo;PALUDETTI, Gaetano;
2009
Abstract
This study analysed the acoustic and vestibular functional and morphological modifi cations in guinea pigs after acoustic trauma. Animals were exposed to noise (6 kHz, at 120 dB SPL for 60 minutes) and then auditory brainstem responses (ABR) and vestibulo-ocular refl ex (VOR) were measured at 6 hours, 1 day, 3, 7, and 21 days after noise. Western blotting and immunostaining for 4-hydroxy-2-noneal (4-HNE) and vascular endothelial growth factor (VEGF) were performed in the cochlear and vestibular regions at 1 and 7 days after noise exposure. A signifi cant decrease of VOR gain was observed on day 1 and the recovery was completed at day 21. ABR threshold values reached a level of 80 dB at day 1 after trauma reaching a value of about 50 dB SPL on day 21. 4-HNE expression, a marker of lipid peroxidation was strongly increased in the cochlea. In the vestibule, 4-HNE immunoreactivity was faint. However, VEGF was upregulated both in the cochlea and vestibule. In conclusion, the expression of VEGF in both cochlear and vestibular structures suggests a reparative role with potentially therapeutic implications.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
