EFFECTS OF LOUD NOISE ON HIPPOCAMPAL AND CEREBELLAR-RELATED BEHAVIORS. ROLE OF OXIDATIVE STATE

URAN, S.L.; CACERES, L.G; GUELMAN, L. R

BRAIN RESEARCH

ELSEVIER SCIENCE BV

Año: 2010 vol. 1361 p. 102 - 114

0006-8993

Living organisms are exposed to potentially hazardous noise levels coming from theenvironment. Besides the direct effect on hearing, extra-auditory noise-associated effectsshould be considered. Since loud noise has been suggested to induce central nervous systemsymptoms, the aim of the present work was to investigate the effect of acute (ANE) andchronic noise exposures (CNE) on different behavioral tasks. To understand themechanisms involved, levels of oxidative status markers were determined in two areasrelated to memory processes, the hippocampus (Hip) and the cerebellum (CE). 15-day-oldmale Wistar rats were exposed to loud noise (95?97 dB, 2 h/day), at ANE or CNE. At 30 days,rats were subjected to different CE and Hip-related behavioral tasks. Reactive oxygen species(ROS) levels and antioxidant enzyme activities (CAT and SOD) were also assessed. Resultsshow impairments in spatial and associative memory in noise-exposed animals. Moreover,a decrease in anxiety levels and an increase in habituation memory were observed in CNEanimals. While an increase in cerebellar ROS levels was found early after the first noiseexposure, a decrease was found in the CE and the Hip at 30 days. The activity ofhippocampal CAT was increased early and remained high in ANE rats, while it wasunchanged in the CE. Finally, although SOD activity was decreased immediately after thefirst noise exposure, its levels were increased at 30 days in ANE rats. In summary, thepresent study shows that an imbalance in oxidative status induced by noise exposure couldunderlie behavioral changes, some of which would be long-lasting.