Exposure of Developing Male Rats to One or Multiple Noise Sessions and Different Housing Conditions: Hippocampal Thioredoxin Changes and Behavioral Alterations

MOLINA, SONIA JAZMÍN; BUJÁN, GUSTAVO EZEQUIEL; RODRIGUEZ GONZALEZ, MONSERRAT; CAPANI, FRANCISCO; GÓMEZ-CASATI, MARIA EUGENIA; GUELMAN, LAURA RUTH

Frontiers in Behavioral Neuroscience

University of Minho

Lugar: Braga; Año: 2019 vol. 13

Exposure of developing rats to noise has shown to induce hippocampal-relatedbehavioral alterations that were prevented after a week of housing in an enrichedenvironment. However, neither the effect of repeated exposures nor its impact on keyendogenous antioxidants had been studied yet. Thus, the aim of the present workwas to reveal novel data about hippocampal oxidative state through the measurementof possible age-related differences in the levels of hippocampal thioredoxins in ratsexposed to noise at different developmental ages and subjected to different schemesand housing conditions. In addition, the possibility that oxidative changes could underliehippocampal-related behavioral changes was also analyzed. Developing maleWistar ratswere exposed to noise for 2 h, either once or for 5 days. Upon weaning, some animalswere transferred to an enriched cage for 1 week, whereas others were kept in standardcages. One week later, auditory and behavioral assessments, as well as measurement ofhippocampal thioredoxin, were performed. Whereas no changes in the auditory functionwere observed, significant behavioral differences were found, that varied according tothe age, scheme of exposure and housing condition. In addition, a significant increase inTrx-1 levels was found in all noise-exposed groups housed in standard cages. Housinganimals in an enriched environment for 1 week was effective in preventing most ofthese changes. These findings suggest that animals become less susceptible to undergobehavioral alterations after repeated exposure to an environmental challenge, probablydue to the ability of adaptation to an unfavorable condition. Moreover, it could behypothesized that damage to younger individuals could be more easily prevented bya housing manipulation.