Validation and use of a computer-assisted counting procedure to quantify BrdU-labeled proliferating cells in the early postnatal mouse hippocampus.

The dentate gyrus is one of the few brain regions that show proliferation of neuronal precursors postnatally and in adult life. Proliferation in the dentate gyrus has been shown to be influenced by exercise, stress and drugs such as antidepressants. Traditionally, proliferation studies rely on the time consuming and subjective manual count of labeled cells. Here we adapted the Metamorph software to automatically count cells labeled in the S phase in the developing dentate gyrus of mice. The validity of the computer-assisted method was established by showing an outcome similar to that obtained with the established manual counting procedure. In addition, by using a genetically modified mouse line with increased proliferation, the ability of the computer-assisted method to detect changes in proliferation was demonstrated.