Parvalbumin-Immunoreactive Neurons Are Not Affected by Trimethyltin-Induced Neurodegeneration in the Rat Hippocampus

The present study investigates, by immunocytochemistry, the behavior of different neuronal subpopulations of the rat hippocampus in neurodegenerative processes induced by the neurotoxicant trimethyltin. The calcium-binding proteins calbindin and parvalbumin are used as selective markers of different neuronal subpopulations. The effects of the neurotoxicant were apparent 21 days after a single i.p. administration with severe neuronal loss, which was significant in CA1 and CA3, as revealed by cell counts after cresyl violet staining. Immunolabeling with calbindin D28-k (CB) and parvalbumin (PV) indicated severe cell loss of CB-containing neurons, essentially reflecting the generalized neuronal loss, while PV-containing neurons appeared to be selectively spared by the neurotoxicant-induced degeneration.