Morphometric analysis of the developing rat brain

In 2 studies, a method of linear morphometry was applied to regulatory deve lopmental neurotoxicity studies in the rat. The first study involved the de velopment of the brain during postnatal days (PNDs) 7-63, and the second in volved the effects of 8 mg/kg IP trimethyltin chloride (TMT) to rats at PND 8, with morphometry performed at PNDs 12 and 24. The results of the TMT li near morphometry were compared with those from stereologic counting of neur ons in the cerebral cortex, piriform cortex, and hippocampus. Stereology pr oduces more meaningful data than simple linear morphometry for use in the r egulatory assessment of the developmental neurotoxicity potential of compou nds.