The Effects of Toluene on Memory Retention in Planaria

Toluene (methylbenzene) is a volatile aromatic hydrocarbon widely used in industrial paints, fuels, and nail polishes. There is evidence that toluene is harmful to the human central nervous system in low levels that adhere to current government regulations: regulations that date back nearly thirty years. It was hypothesized that even in authorized quantities, topical exposure to toluene would adversely affect memory retention in G. tigrina (planaria). Experimentation was done to investigate the effects of government approved toluene levels on Y-Maze performance in planaria. Five groups of ten planaria were trained to turn right in a Y-Maze through the use of light as a negative stimulus. After being topically exposed to either water, acetone, or toluene and acetone, planaria were truncated and left to regenerate before being finally tested. Y-Maze completion time and choice accuracy were recorded throughout testing and compared with corresponding pre-treatment values. ANOVA testing yielded p-values of 0.00179, 0.000162, and 0.00582 within toluene-exposed groups, implying significant memory impairment and ultimately warranting a reconsideration of current federal toluene standards.