gms | German Medical Science

82nd Annual Meeting of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery

German Society of Oto-Rhino-Laryngology, Head and Neck Surgery

01.06. - 05.06.2011, Freiburg

Sensitivity to stress of the auditory system of Wistar Han rats

Meeting Abstract

Search Medline for

German Society of Oto-Rhino-Laryngology, Head and Neck Surgery. 82nd Annual Meeting of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery. Freiburg, 01.-05.06.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. Doc11hno34

doi: 10.3205/11hno34, urn:nbn:de:0183-11hno348

Published: August 3, 2011

© 2011 Mazurek et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Introduction: Our recent study has shown that 24-h exposure to stress induces hypersensitivity in the auditory system of Wistar Harlan rats lasting up to one day. In our present work, the same research model was used to test Wistar Han rats to identify strain differences in susceptibility to stress.

Methods: The animals were exposed to a low-intensity and low-frequency noise (1 s, 300 Hz, 15-s interval, 61–65 dB A) for 24 h. In addition, the device induced slight vibration of the cage. Auditory brainstem response (ABR) was measured at different times post-stress. In addition, we determined the concentration of stress markers in serum and examined the expression of selected proteins in the inferior colliculus (IC) and auditory cortex (AC) using a Western blot. Non-stressed animals served as controls.

Results: Immediately after stress, we found a transient hearing loss, which was followed by decrease of the ABR thresholds. This auditory hypersensitivity was most pronounced after 24 h and was still detectable one week later. Six hours post-stress, corticosterone and TNFa were only slightly increased in serum, whereas the concentration of BDNF increased significantly. Three hours after stress, expression of BDNF in the IC and AC was higher than in the controls. AMPA2 receptor protein increased in the IC and AC after 6 h and 24 h to 1 week, respectively. The AMPA3 increased in the AC after 3 h.

Conclusion: Dissimilar to Wistar Harlan rats, exposure of Wistar Han rats to stress induced a transient hearing loss followed by long-lasting hypersensitivity of the auditory system. The slow and small increase of corticosterone implies a disturbance in the HPA axis. Changes in BDNF and AMPA protein expression could be indicative of the synaptic plasticity.