Enriched environment can prevent most behavioral alterations induced by different schedules of noise exposure

S. J. MOLINA, M. SAINT-MARTIN, F. CAPANI, *L. R. GUELMAN;

Washigton

Conferencia; American Society for Neuroscience; 2014

It is known that acute noise exposure can induce transient or permanent hearing loss. However, few data are available regarding its effects on extra-auditory structures, in particular within developing Central Nervous System (CNS). Previous studies of our laboratory showed that exposure of 15-days-old rats to moderate noise during 2 hours can induce hippocampus (HC)-related behavioral, biochemical and histological alterations, including changes in anxiety-like behaviors. Nevertheless, no data on the behavioral effects induced by noise in other exposure schedules have been obtained yet. Moreover, since the use of potential strategies of neuroprotection has not been explored in our model, rearing noise-exposed animals in an enriched environment (EE) was used as a non-pharmacological tool. Therefore, the aim of the present work was to test if EE can prevent behavioral changes induced by exposure to noise using different exposure schedules. Rats of 15 days were exposed during 2 hours to white noise (95-97 dBA), for one or five consecutive days, using an ?ad-hoc? sound camera. 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. One week later, different behavioral tests were performed, including open field (OF), elevated plus maze (EPM) and inhibitory avoidance (IA) tasks. Results show that whereas no changes in associative or habituation memory were found in rats exposed to noise for 2 h, significant changes were observed when rats were exposed for 5 consecutive days. In addition, a decrease in anxiety-like behaviors was observed in both groups, which could be interpreted as a maladaptive behavior. Rearing rats in EE almost fully prevented these noise-induced behavioral changes. These findings suggest that visual, social and/or physical stimulation during the peri-adolescence period, after exposure to a physical agent such as noise, might contribute to stabilization of normal emotional and behavioral parameters.