Correlation between behavioral and pathological changes in the evaluation of neurotoxicity.

Recently the EPA has implemented new guidelines under Section 4 of TSCA to undertake neurotoxicity testing. It is expected that other agencies, both national and international, will follow suit. The evaluation of neurotoxicity will be based primarily on behavioral and morphological observations and particularly on the correlation between them. Initially, considerable information will have to be gathered from various laboratories to form the background data on which decisions of toxic effects can be made. This paper presents our experience to date with behavioral and neuropathological procedures for the evaluation of chemical compounds or dietary regimens in rats for potential neurotoxicity. Reference is made to acrylamide, 2,5-hexanedione, 3,3'-iminodipropionitrile, amphetamine, physostigmine, ethanol, triethyltin, food and water deprivation, and carbon tetrachloride. The question of whether every change induced by xenobiotics can be considered as a sign of toxicity is discussed.