Age-dependent changes might be induced in a rat hippocampal oxidative marker after noise exposure. Potential restoration after rearing in an enriched environment.

MOLINA, SJ; GUELMAN, LR; CAPANI, F; MICELI, M

San Diego, CA

Congreso; 46th Annual Meeting of the Society for Neuroscience (SFN); 2016

Society for Neuroscience (SFN)

It is well known that noise exposure can induce transient or permanent hearing loss. However, few data are available regarding its effects on extra-auditory structures, mainly within developing Central Nervous System.Previous studies of our laboratory showed that exposure of immature rats (7 and 15-days-old) to moderate noise during 2 hours, can induce hippocampushippocampal-related behavioral alterationsalterations that differ depending on the age of exposure. Moreover, rearing these animals in an enriched environment (EE) has shown to be an effective protective tool which almost fully prevented noise-induced behavioral changes. Previous studies also observed a correlation with changes in hippocampal oxidative status. Therefore, the aim of the present work was to test if noise exposure at different ages might generate hippocampal oxidative hippocampal changes in an oxidative marker such as Trx-1. The possible potential prevention of these changes through the use of an enriched environment (EE) was also assessed. Rats of 7 and 15 days were exposed during 2 h to white noise (95-97 dB) for one day. After weaning, groups of 3-4 rats were transferred to an enriched cage, consisting of toys, a wheel, tunnels and ramps, while other groups were placed in standard cages. After one week, levels of Trx-1, a member of the family of the antioxidants thioredoxins, were evaluated.Results showed that Trx-1 levels of rats exposed at 7 days and reared in standard cages were increased, whereas no significant changes were found in rats reared in EE when compared with their respective control animals. In contrast, animals exposed at 15 days showed no significant differences in Trx-1 levels, neither in standard nor in enriched conditions.These findings suggest that different noise exposure ages at an earlyseveral developmental ages might differentially affect hippocampal oxidative status. An oxidative imbalance might be triggered after noise exposure at an early age. The restore restoration ofin hippocampal Trx-1 levels in exposed animals reared in an EE might be correlated with a more reduced cellular milieu after facilitated by EE rearing, suggesting that EE this strategy could be a useful strategy that mightto allow aid animals to cope with an unfavorable condition.