CONICET | Buscador de Institutos y Recursos Humanos

Behavioral effects induced by early noise exposure: impact of housing in an enriched environmentMolina, SJ1, Capani, F2 and Guelman, LR1,31 Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires. Centro de Estudios Farmacológicos y Botánicos (CEFyBO, UBA-CONICET). Buenos Aires, Argentina. 2 Laboratorio de plasticidad y citoaerquitectura neuronal, ININCA-CONICET, Buenos Aires, Argentina. 3 Universidad de Buenos Aires. Facultad de Medicina. 1ª Cátedra de Farmacología. Buenos Aires, Argentina.Noise can be defined as an unpleasant sound, in general of high intensity. Even though it is known that noise exposure can induce transient or permanent hearing loss, few data are available regarding its effects on extra-auditory structures, in particular within developing Central Nervous System (CNS). Therefore, the aim of the present work was to test the behavioral effects induced in immature rats after moderate noise exposure using different schedules and the potential neuroprotective action of an enriched environment (EE), a non-pharmacological tool that has been demonstrated to be effective after different injuries. Rats of 15 days were exposed during 2 hours to white noise (95-97 dBA), for one (N1) or five consecutive days (N5), 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, elevated plus maze and inhibitory avoidance tasks. Results showed behavioral differences between noise-exposed animals depending on the schedule of exposure. While N1 rats had a better performance in an associative memory task and a deficit in habituation memory when compared with sham animals, no significant changes were found in N5 rats. Interestingly, housing in an EE fully prevented the changes found in N1 rats.On the other hand, N1 rats showed a decrease in exploratory and an increase in anxiety-like behaviors. None of these changes were prevented by housing in an EE. However, N5 rats showed the opposite result: an increase in exploratory and a decrease in anxiety-like behaviors. In addition, EE fully prevented the behavioral alterations found in N5 rats.These findings suggest that different noise schedules, either one or five daily exposures, can differentially affect behavioral performances when noise is present at an early developmental age. Moreover, housing rats in EE might reverse some of the behavioral changes induced by a previous exposure to noise.Therefore, it could be concluded that developing CNS might be susceptible to the effect of an environmental agent such as noise and that visual, social and/or physical stimulation during the peri-adolescence period could be a successful tool that can contribute to the stabilization of emotional and behavioral parameters.