Comment on the Interpretation of Effects Caused by Chronic Trichloroethylene Exposure

Work was started with the intention of testing effects on the central nervous system from exposure to trichloroethylene. In the experiments the authors used a symetrical labyrinth as a probe for spatial memory. This behavior is extremely sensitive to damage in the hippocampal area, while other parts of the brain seem not to be involved in any prominent way. Results were that no effects on seedseeking behavior in the labyrinth could be seen during the solvent exposure or after it had been terminated. If, however, the animals were challenged by a second exposure several months after termination of the first, significant differences between the previously exposed animals and the controls were found. The effects can be considered both as irreversible and covert.