IMPACT OF LOUD NOISE ON ASSOCIATIVE MEMORY. RAT HIPPOCAMPAL NEURONAL ALTERATION AND OXIDATIVE STATUS IMBALANCE

URAN, S.L; AÓN, L; CACERES, L.G; CAPANI, F; GUELMAN, L.R

Rosario, Santa Fé, Argentina

Congreso; XLI Reunión Anual de la Sociedad Argentina de Farmacología Experimental; 2009

Sociedad Argentina de Farmacología Experimental

Central Nervous System (CNS) is vulnerable to reactive oxygen species (ROS). The aim of the present work was to test if loud noise exposure can affect hippocampal-related memory, histology and oxidative status. 15-days-old male Wistar rats were exposed to white noise (100dB) and separated into acute (2h/day) and chronic exposure (2h/day for 15d). Passive avoidance test (PA), hippocampal ROS levels, antioxidant enzymes activities (SOD/CAT) as well as histological assessments were performed at 30 and 90-days-old rats. Results show a decreased latency to enter the dark compartment in PA only at 30 days when compared to control animals. ROS levels were decreased, while antioxidant enzymes activities were increased after noise exposure in 30 days-old-rats. Histological abnormalities were found only at 30 days in CA1 and dentate gyrus. Data suggest that loud noise is capable of inducing temporary memory impairments. The increase in CAT and SOD activities could be triggered as a compensatory response to hippocampal noise-induced damage, leading to a decrease in ROS levels at 30 days. The improvement in the performance at 90 days could be related to the lack of damage in hippocampus at this age.