Urban traffic noise pollution disturbs spatial learning and memory and increases anxiety-like behavior in adult male rats

Noise pollution is an unwanted inevitable distribution of the modern and industrialized life of mankind. With the expansion of urban life, humans are daily exposed to noise pollution which can cause anxiety and disorders in cognitive activities. The present study was aimed to investigate the impact of sub-chronic urban traffic noise pollution on learning, memory and anxiety-like behavior in adult male rats. Thirty two adult male Wistar rats (weighing 275-300g) were used in the present experimental study. The animals were divided into two groups: the control and the noise-exposed. The rats in the test group were exposed to a 90dB noise recorded from a crowded street traffic for 6h/10 days. Control rats were intact. Morris water maze (MWM) and an elevated plus maze (EPM) were used to assess spatial learning and memory and anxiety-like behavior in rats. The findings displayed that both control and noise-exposed group improved their maze steering over 4 days of experiment in MWM; however, noise-exposed group had more latency and traveled-distance in MWM to find the hidden platform in probe trial compared to those of control (P<0.05). Moreover, noise-exposed group showed a significant increase in weight gain compared to the control group (P<0.05). In addition, the spent time in open arm of the EPM was significantly decreased compared to controls (P<0.05). Urban traffic noise pollution for a short-term period causes a meaningful increase on weight gain, disorders in retrieval memory and increase in anxiety-like behavior in rats.