Evaluation of bisphenol a towards spatial memory and learning impairment in adult zebrafish

Abstract

The production of bisphenol A (BPA) has been widely used in plastics and resin production. The effect of BPA on the human brain and behavior raises concern about its possible impact on adults as it is associated with adverse behavior and learning deficits. Herein, we assess the effect of BPA on adult zebrafish spatial memory and learning impairment by using T-maze. In the toxicity study, zebrafish embryos were treated with 1.25 ^g/ml, 5 ^g/ml, and 125 ^g/ml BPA concentrations for cytotoxic effects observation. After subsequent behavioral training, T-maze tests were conducted on days 1, 4, 7, 10, and 12 of a 12-day BPA exposure (at concentrations of 1.25 ^g/ml and 5 ^g/ml). The protocol of T-maze was based on associative learning, which involved associating a visual stimulus (color) with a natural stimulus (food). Toxicity study demonstrated viability of BPA concentration decreased in the order of 125>5>1.25 ^g/ml,, abnormally decreased heartbeat and delayed hatching rate towards higher concentration. Control group showed adult zebrafish are able to perform associative learning tasks. Fish that received 1.25 ^g/ml did not exhibit a significant difference in performance from control fish, and fish that received the 5 ^g/ml performed significantly worse than lower concentration. Exposure of 5 ^g/ml BPA towards zebrafish shows significant memory and learning impairment. The exposures we obtained from any common plastics that we used daily could contribute to the total amount of endocrine disrupting compounds and affect neurobehavior.