Abstract |
Occupational exposure to styrene monomer has been associated with cognitive dysfunction in humans, and changes in dopaminergic function have been suggested to underly effects of repeated exposure to styrene monomer in animals. The study was designed to determine whether styrene and/or dopaminergic drugs affect working and reference memory in animals. Male Long-Evans rats were administered styrene by gavage at 4.5 - 6.5 months of age, and subsequently trained to perform an appetitive operant task which allowed daily quantification of working memory (accuracy of spatial delayed nonmatching-to-position), reference memory (accuracy of visual discrimination), perseverative responding (position bias) and motor function (choice lever press latencies and nosepoke inter-response times during delay). Styrene alone did not affect acquisition or any measure of performance on this task. The effects of the dopamine reuptake inhibitor d-amphetamine (0.3 - 1.0 mg/kg), the D1 agonist SKF 38393 (1.0 - 3.0 mg/kg), the D1 antagonist SCH 23390 (0.01 - 0.03 mg/kg), the D2 agonist quinpirole (0.01 - 0.056 mg/kg), and the D2 antagonist raclopride (0.056 - 0.177 mg/kg) were then assessed in control and styrene-treated rats. |