Effect of bisphenol A exposure on spontaneous behavior using the elevated plus maze test

Abstract

The elevated plus maze (EPM) test is widely used with experimental animals to evaluate anxiety, which is most often indicated by the open‐arm staying time. However, little attention has been focused on general spontaneous behaviors (such as locomotor activity, rearing and grooming) using this test. We compared the scores for the same parameter of spontaneous behavior using both the EPM test and the open‐field test (OFT). Then, using an exposure model of bisphenol A (BPA), which is an endocrine‐disrupting chemical, we evaluated its impact on the scores for both tests. In control males, a significant positive correlation was confirmed for all parameters between the two tests. In females, none of the three parameters reached significance. With the BPA exposure model, locomotor activity and rearing showed similar results to those of the control group for both males and females. In grooming, there was a very low correlation between the EPM test and the OFT. When the mean values were compared using the OPT between the control and BPA groups, there was an increase in rearing and a decrease in grooming in the BPA males. On the other hand, in females, effects were seen when using the EPM test. In the BPA females, there were high values for locomotor activity and rearing, and low values for grooming. In grooming behavior, the OPT score was lower in the BPA males, while the EPM test score was lower in the BPA females. The impact of BPA exposure on spontaneous behavior depended on the experimental equipment and gender. (J Osaka Dent Univ 2019; 53: 187‐192)