Deformed dendrites and reduced spine numbers on ectopic neurones in the hippocampus of rats exposed to methylazoxymethanol-acetate. A Golgi-Cox study.

Clusters of ectopic neurones appeared in the hippocampus of rat offspring which were exposed to the alkylating neurotoxin methylazoxymethanol-acetate (MAMac) during foetal development. The offspring were 30 and 60 days old when their brains were removed and prepared by the Golgi-Cox procedure outlined by Sholl (1953). Reductions in the number of dendritic branches, changes in apical dendritic lengths, abnormalities in the shapes of the dendritic shafts, and significant diminution in spine numbers were observed in ectopic neurones. The significance of these pathological alterations in dendritic morphology is discussed with special reference to the findings of an earlier study which revealed that afferent axons terminate upon ectopic neurones in an abnormal way.