Trimethyltin-induced changes in gross morphology of the hippocampus

Acute exposure to trimethyltin (TMT) produces alterations in hippocampal morphology. The purpose of this study was to arrive at a simple method for quantitative assessment of the gross changes in morphology which could then be used as a correlate in studies of TMT toxicity. Adult Long-Evans male hooded rats were treated with a single dose of TMT chloride and sacrificed either (a) within 11 days; (b) following 30 days; or (c) 105 days following treatment. Among a variety of morphological measures explored, the easiest and most clearly dosage-related was length of the line of pyramidal cells, from CA1 through CA3c. TMT shortened this line in a dosage- and time-dependent manner. Loss of cells appeared to begin in CA3c and progress through CA3b and CA3a as a dosage and time since treatment increased. It was concluded that this measurement may provide a useful morphological correlate for physiological and behavioral studies of TMT toxicity.