Hippocampal Neurogenesis in Ames Dwarf Mice

Abstract

Neuronal generation had been thought to occur only during development; however, current research indicates that neurogenesis continues into adulthood in the hippocampus and olfactory regions. The model selected for study was the Ames Dwarf mouse, homozygous for the PROP‐1 gene mutation and deficient in pituitary hormones. Normal‐sized heterozygous litter mates were used as controls. The goal was to determine whether there were alterations in brain neurogenesis using the bromodeoxyuridine (BrdU) method to label dividing cells. 12‐month‐old male Dwarf and control mice (n=5–6/group) were injected IP for seven days with 50mg/kg of BrdU. Animals were perfused with paraformaldehyde, and consecutive 25 um sections were taken through the hippocampus. Immunofluorescence was used to localize BrdU and neuronal nuclear antigen, NeuN, a marker for mature neurons. There was no difference in the number of BrdU‐positive cells in Dwarf mice as compared to controls (13.5 ± 5.1 vs 12.6 ± 2.7). The percentage of co‐labeled BrdU and NeuN neurons showed a trend to be higher in Dwarf mice (69.9 ± 5.9% vs. 61.9 ± 12.6%; Dwarf vs control). Data indicate that there is an increase in proliferation of neural progenitor cells that can develop into mature neurons in the hippocampus of Ames Dwarf mice over controls. Supported by NIH R25GM086257 and Henry Jackson Foundation Subaward #686190.