Neurotoxic effect of high dose methamphetamine administration on the hippocampal formation of adult mice: morphometric study using image analyzer.
The volume of the hippocampal formation was measured after repeated methamphetamine (MAP) administration. MAP (30 mg/kg, i.p.) or an equivalent volume of saline (SAL) was administered once daily for 5 days to adult male BALB/c mice. The animals were perfused 7 days after the last injection, and brain sections were stained with cresyl violet and studied with a computer-assisted image analyzer. The volume of the molecular layer at the ventral position of the dentate gyrus of MAP-treated animals was significantly decreased (77% of control, p < 0.001). In contrast, the volumes of the molecular layers at the dorsal and midseptal positions of the dentate gyrus did not change after MAP administration. Similarly, repeated MAP treatment did not affect the volumes of the granular layer and hilus at the dorsal, midseptal or ventral positions of the dentate gyrus. The present results are the first to document a persistent neurotoxic effect of high dose MAP administration on the hippocampal volume of adult mice.